145 results on '"Aleksandra Radjenovic"'
Search Results
2. Muscle protein synthesis and muscle/metabolic responses to resistance exercise training in South Asian and White European men
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Faris F. Aba Alkhayl, Ahmad D. Ismail, Carlos Celis-Morales, John Wilson, Aleksandra Radjenovic, Lynsey Johnston, Paul Welsh, Naveed Sattar, Jason M. R. Gill, Tom Preston, and Stuart R. Gray
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Medicine ,Science - Abstract
Abstract The aims of the current study, therefore, were to compare (1) free-living MPS and (2) muscle and metabolic adaptations to resistance exercise in South Asian and white European adults. Eighteen South Asian and 16 White European men were enrolled in the study. Free-living muscle protein synthesis was measured at baseline. Muscle strength, body composition, resting metabolic rate, VO2max and metabolic responses (insulin sensitivity) to a mixed meal were measured at baseline and following 12 weeks of resistance exercise training. Free-living muscle protein synthesis was not different between South Asians (1.48 ± 0.09%/day) and White Europeans (1.59 ± 0.15%/day) (p = 0.522). In response to resistance exercise training there were no differences, between South Asians and White Europeans, muscle mass, lower body strength or insulin sensitivity. However, there were differences between the ethnicities in response to resistance exercise training in body fat, resting carbohydrate and fat metabolism, blood pressure, VO2max and upper body strength with responses less favourable in South Asians. In this exploratory study there were no differences in muscle protein synthesis or anabolic and metabolic responses to resistance exercise, yet there were less favourable responses in several outcomes. These findings require further investigation.
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- 2022
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3. Myocardial changes on 3T cardiovascular magnetic resonance imaging in response to haemodialysis with fluid removal
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Alastair J. Rankin, Kenneth Mangion, Jennifer S. Lees, Elaine Rutherford, Keith A. Gillis, Elbert Edy, Laura Dymock, Thomas A. Treibel, Aleksandra Radjenovic, Rajan K. Patel, Colin Berry, Giles Roditi, and Patrick B. Mark
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End-stage kidney disease ,Haemodialysis ,Cardiovascular ,Magnetic resonance imaging ,Left ventricular hypertrophy ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Abstract Background Mapping of left ventricular (LV) native T1 is a promising non-invasive, non-contrast imaging biomarker. Native myocardial T1 times are prolonged in patients requiring dialysis, but there are concerns that the dialysis process and fluctuating fluid status may confound results in this population. We aimed to assess the changes in cardiac parameters on 3T cardiovascular magnetic resonance (CMR) before and after haemodialysis, with a specific focus on native T1 mapping. Methods This is a single centre, prospective observational study in which maintenance haemodialysis patients underwent CMR before and after dialysis (both scans within 24 h). Weight measurement, bio-impedance body composition monitoring, haemodialysis details and fluid intake were recorded. CMR protocol included cine imaging and mapping native T1 and T2. Results Twenty-six participants (16 male, 65 ± 9 years) were included in the analysis. The median net ultrafiltration volume on dialysis was 2.3 L (IQR 1.8, 2.5), resulting in a median weight reduction at post-dialysis scan of 1.35 kg (IQR 1.0, 1.9), with a median reduction in over-hydration (as measured by bioimpedance) of 0.75 L (IQR 0.5, 1.4). Significant reductions were observed in LV end-diastolic volume (− 25 ml, p = 0.002), LV stroke volume (− 13 ml, p = 0.007), global T1 (21 ms, p = 0.02), global T2 (− 1.2 ms, p = 0.02) following dialysis. There was no change in LV mass (p = 0.35), LV ejection fraction (p = 0.13) or global longitudinal strain (p = 0.22). On linear regression there was no association between baseline over-hydration (as defined by bioimpedance) and global native T1 or global T2, nor was there an association between the change in over-hydration and the change in these parameters. Conclusions Acute changes in cardiac volumes and myocardial native T1 are detectable on 3T CMR following haemodialysis with fluid removal. The reduction in global T1 suggests that the abnormal native T1 observed in patients on haemodialysis is not entirely due to myocardial fibrosis.
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- 2021
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4. Cardiovascular magnetic resonance for the detection of descending thoracic aorta calcification in patients with end-stage renal disease
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Elbert Edy, Alastair J. Rankin, Jennifer S. Lees, Pauline Hall Barrientos, Rosemary Woodward, Sokratis Stoumpos, Ioannis Koktzoglou, Robert R. Edelman, Aleksandra Radjenovic, Patrick B. Mark, and Giles H. Roditi
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Thoracic aortic calcification ,End-stage renal disease ,Cardiovascular disease ,Computed tomography ,Magnetic resonance imaging ,Radial volumetric interpolated breath-hold examination (radial-VIBE) sequence ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Abstract Background Vascular calcification is an independent predictor of cardiovascular disease in patients with chronic kidney disease. Computed tomography (CT) is the gold-standard for detecting vascular calcification. Radial volumetric-interpolated breath-hold examination (radial-VIBE), a free-breathing gradient-echo cardiovascular magnetic resonance (CMR) sequence, has advantages over CT as it is ionising radiation-free. However, its capability in detecting thoracic aortic calcification (TAC) has not been investigated. This study aims to compare radial-VIBE to CT for the detection of TAC in the descending aorta of patients with end-stage renal disease (ESRD) using semi-automated methods, and to investigate the association between TAC and coronary artery calcification (CAC). Methods Paired cardiac CT and radial-VIBE CMR scans from ESRD patients participating in 2 prospective studies were obtained. Calcification volume was quantified using semi-automated methods in a 9 cm segment of the thoracic aorta. Correlation and agreement between TAC volume measured on CMR and CT were assessed with Spearman’s correlation coefficient (ρ), linear regression, Bland–Altman plots and intraclass correlation coefficient (ICC). Association between CAC Agatston score and TAC volume determined by CT and CMR was measured with Spearman’s correlation coefficient. Results Scans from 96 participants were analysed. Positive correlation was found between CMR and CT calcification volume [ρ = 0.61, 95% confidence interval (CI) 0.45–0.73]. ICC for consistency was 0.537 (95% CI 0.378–0.665). Bland–Altman plot revealed that compared to CT, CMR volumes were systematically higher at low calcification volume, and lower at high calcification volume. CT did not detect calcification in 41.7% of participants, while radial-VIBE CMR detected signal which the semi-quantitative algorithm reported as calcification in all of those individuals. Instances of suboptimal radial-VIBE CMR image quality were deemed to be the major contributors to the discrepancy. Correlations between CAC Agatston score and TAC volume measured by CT and CMR were ρ = 0.404 (95% CI 0.214–0.565) and ρ = 0.211 (95% CI 0.008–0.396), respectively. Conclusion Radial-VIBE CMR can detect TAC with strong positive association to CT, albeit with the presence of proportional bias. Quantification of vascular calcification by radial-VIBE remains a promising area for future research, but improvements in image quality are necessary.
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- 2021
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5. Diagnostic Accuracy of 3.0‐T Magnetic Resonance T1 and T2 Mapping and T2‐Weighted Dark‐Blood Imaging for the Infarct‐Related Coronary Artery in Non–ST‐Segment Elevation Myocardial Infarction
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Jamie Layland, Samuli Rauhalammi, Matthew M. Y. Lee, Nadeem Ahmed, Jaclyn Carberry, Vannesa Teng Yue May, Stuart Watkins, Christie McComb, Kenneth Mangion, John D. McClure, David Carrick, Anna O'Donnell, Arvind Sood, Margaret McEntegart, Keith G. Oldroyd, Aleksandra Radjenovic, and Colin Berry
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acute coronary syndrome ,area at risk ,edema ,mapping ,noninvasive imaging ,non–ST‐segment elevation acute coronary syndrome ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
BackgroundPatients with recent non–ST‐segment elevation myocardial infarction commonly have heterogeneous characteristics that may be challenging to assess clinically. Methods and ResultsWe prospectively studied the diagnostic accuracy of 2 novel (T1, T2 mapping) and 1 established (T2‐weighted short tau inversion recovery [T2W‐STIR]) magnetic resonance imaging methods for imaging the ischemic area at risk and myocardial salvage in 73 patients with non–ST‐segment elevation myocardial infarction (mean age 57±10 years, 78% male) at 3.0‐T magnetic resonance imaging within 6.5±3.5 days of invasive management. The infarct‐related territory was identified independently using a combination of angiographic, ECG, and clinical findings. The presence and extent of infarction was assessed with late gadolinium enhancement imaging (gadobutrol, 0.1 mmol/kg). The extent of acutely injured myocardium was independently assessed with native T1, T2, and T2W‐STIR methods. The mean infarct size was 5.9±8.0% of left ventricular mass. The infarct zone T1 and T2 times were 1323±68 and 57±5 ms, respectively. The diagnostic accuracies of T1 and T2 mapping for identification of the infarct‐related artery were similar (P=0.125), and both were superior to T2W‐STIR (P
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- 2017
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6. Temporal Evolution of Myocardial Hemorrhage and Edema in Patients After Acute ST‐Segment Elevation Myocardial Infarction: Pathophysiological Insights and Clinical Implications
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David Carrick, Caroline Haig, Nadeem Ahmed, Samuli Rauhalammi, Guillaume Clerfond, Jaclyn Carberry, Ify Mordi, Margaret McEntegart, Mark C. Petrie, Hany Eteiba, Stuart Hood, Stuart Watkins, M. Mitchell Lindsay, Ahmed Mahrous, Paul Welsh, Naveed Sattar, Ian Ford, Keith G. Oldroyd, Aleksandra Radjenovic, and Colin Berry
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magnetic resonance imaging ,myocardial edema ,myocardial hemorrhage ,myocardial infarction ,pathophysiology ,reperfusion injury ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
BackgroundThe time course and relationships of myocardial hemorrhage and edema in patients after acute ST‐segment elevation myocardial infarction (STEMI) are uncertain. Methods and ResultsPatients with ST‐segment elevation myocardial infarction treated by primary percutaneous coronary intervention underwent cardiac magnetic resonance imaging on 4 occasions: at 4 to 12 hours, 3 days, 10 days, and 7 months after reperfusion. Myocardial edema (native T2) and hemorrhage (T2*) were measured in regions of interest in remote and injured myocardium. Myocardial hemorrhage was taken to represent a hypointense infarct core with a T2* value
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- 2016
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7. Correction: Orthogonal Invariant Sets of the Diffusion Tensor and the Development of a Curvilinear Set Suitable for Low-Anisotropy Tissues.
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Robin A. Damion, Aleksandra Radjenovic, Eileen Ingham, Zhongmin Jin, and Michael E. Ries
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Medicine ,Science - Published
- 2014
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8. Orthogonal invariant sets of the diffusion tensor and the development of a curvilinear set suitable for low-anisotropy tissues.
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Robin A Damion, Aleksandra Radjenovic, Eileen Ingham, Zhongmin Jin, and Michael E Ries
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Medicine ,Science - Abstract
We develop a curvilinear invariant set of the diffusion tensor which may be applied to Diffusion Tensor Imaging measurements on tissues and porous media. This new set is an alternative to the more common invariants such as fractional anisotropy and the diffusion mode. The alternative invariant set possesses a different structure to the other known invariant sets; the second and third members of the curvilinear set measure the degree of orthotropy and oblateness/prolateness, respectively. The proposed advantage of these invariants is that they may work well in situations of low diffusion anisotropy and isotropy, as is often observed in tissues such as cartilage. We also explore the other orthogonal invariant sets in terms of their geometry in relation to eigenvalue space; a cylindrical set, a spherical set (including fractional anisotropy and the mode), and a log-Euclidean set. These three sets have a common structure. The first invariant measures the magnitude of the diffusion, the second and third invariants capture aspects of the anisotropy; the magnitude of the anisotropy and the shape of the diffusion ellipsoid (the manner in which the anisotropy is realised). We also show a simple method to prove the orthogonality of the invariants within a set.
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- 2013
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9. Effect of Empagliflozin on Kidney Biochemical and Imaging Outcomes in Patients With Type 2 Diabetes, or Prediabetes, and Heart Failure with Reduced Ejection Fraction (SUGAR-DM-HF)
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Matthew M.Y. Lee, Keith A. Gillis, Katriona J.M. Brooksbank, Sarah Allwood-Spiers, Pauline Hall Barrientos, Kirsty Wetherall, Giles Roditi, Bashair AlHummiany, Colin Berry, Ross T. Campbell, Victor Chong, Liz Coyle, Kieran F. Docherty, John G. Dreisbach, Bernd Kuehn, Catherine Labinjoh, Ninian N. Lang, Vera Lennie, Kenneth Mangion, Alex McConnachie, Clare L. Murphy, Colin J. Petrie, John R. Petrie, Kanishka Sharma, Steven Sourbron, Iain A. Speirits, Joyce Thompson, Paul Welsh, Rosemary Woodward, Ann Wright, Aleksandra Radjenovic, John J.V. McMurray, Pardeep S. Jhund, Mark C. Petrie, Naveed Sattar, and Patrick B. Mark
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Heart Failure ,Prediabetic State ,Diabetes Mellitus, Type 2 ,Glucosides ,Physiology (medical) ,Humans ,Stroke Volume ,Benzhydryl Compounds ,Cardiology and Cardiovascular Medicine ,Kidney - Abstract
No abstract available.
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- 2022
10. Effect of the phosphodiesterase 4 inhibitor apremilast on cardiometabolic outcomes in psoriatic disease—results of the Immune Metabolic Associations in Psoriatic Arthritis study
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Naveed Sattar, Iain B. McInnes, John Harvie, Aleksandra Radjenovic, Rosemary Brown, Katriona Brooksbank, Paul Welsh, Caron Paterson, Xuan Gao, Stefan Siebert, Lyn D. Ferguson, Dominic Rimmer, Susanne Cathcart, and Gary Semple
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Adult ,Male ,medicine.medical_specialty ,Adipose tissue ,Gastroenterology ,030207 dermatology & venereal diseases ,03 medical and health sciences ,Psoriatic arthritis ,chemistry.chemical_compound ,0302 clinical medicine ,Rheumatology ,Weight loss ,Psoriasis ,Internal medicine ,Adipocyte ,Weight Loss ,medicine ,Body Fat Distribution ,Humans ,Glucose homeostasis ,Pharmacology (medical) ,Prospective Studies ,030203 arthritis & rheumatology ,business.industry ,Arthritis, Psoriatic ,Weight change ,Cardiometabolic Risk Factors ,Middle Aged ,medicine.disease ,Thalidomide ,chemistry ,Female ,Phosphodiesterase 4 Inhibitors ,Apremilast ,medicine.symptom ,business ,medicine.drug - Abstract
Objectives Studies have suggested phosphodiesterase 4 (PDE4) inhibition may be associated with weight loss and other cardiometabolic benefits. We evaluated the effect of the PDE4 inhibitor apremilast on body weight and composition, glucose homeostasis, lipid profiles and vascular function in psoriatic disease and whether weight change correlated with therapeutic response. Methods We conducted a prospective, open-label study (Immune Metabolic Associations in Psoriatic Arthritis) of adults receiving apremilast 30 mg as part of routine care for PsA and/or psoriasis. Cardiometabolic, anthropometric and disease activity assessments were performed at baseline (pre-apremilast) and at months 1, 3 and 6 of apremilast treatment in 60 patients. A subgroup underwent further assessment of endothelial function, body composition and adipocyte morphology. Results In patients (median age 54.5 years, 63% women, median BMI 33.2 kg/m2), apremilast was associated with a mean weight loss of 2.2 kg (95% CI 1.4, 3.0; P Conclusion Following apremilast treatment, we observed weight loss, principally abdominal subcutaneous fat, and improvement in psoriatic disease activity. The latter was independent of weight change, suggesting apremilast likely acts through direct immunological mechanisms.
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- 2021
11. Quality assurance of quantitative cardiac T1-mapping in multicenter clinical trials – A T1 phantom program from the hypertrophic cardiomyopathy registry (HCMR) study
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Dipan J. Shah, Han W. Kim, Michael Salerno, Bette Kim, Aleksandra Radjenovic, Milind Y. Desai, Iulia A. Popescu, Sven Plein, David M. Higgins, Tarik Hafyane, Michelle Michels, Stefan K. Piechnik, Kyle Autry, Kelvin Chow, Christopher M. Kramer, Stefan L. Zimmerman, James A. White, Ntobeko A B Ntusi, Taigang He, Dana Dawson, Craig S. Broberg, Ornella Rimoldi, Linda Calistri, Amedeo Chiribiri, Chiara Bucciarelli-Ducci, Steffen Huber, Lisa M Anderson, Mark B.M. Hofman, Sanjay K Prasad, Joanne Wormleighton, Qiang Zhang, Stefano Colagrande, Flett Andrew, Michael Jerosch-Herold, Luca Biasiolli, Elizabeth R. Jenista, Konrad Werys, Iacopo Carbone, Heiko Mahrholdt, Javier Sanz, Raymond Y. Kwong, Jeanette Schulz-Menger, Redha Boubertakh, Saidi A Mohiddin, David A. Broadbent, Gerry P McCann, Scott Semple, David E. Newby, Vanessa M Ferreira, Stefan Neubauer, Cardiology, Radiology and nuclear medicine, ACS - Atherosclerosis & ischemic syndromes, and ACS - Heart failure & arrhythmias
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Magnetic Resonance Spectroscopy ,Coefficient of variation ,Phantom study ,030204 cardiovascular system & hematology ,Imaging phantom ,Article ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,030212 general & internal medicine ,Quantitative T1-mapping ,Registries ,Cardiac MRI ,Protocol (science) ,medicine.diagnostic_test ,business.industry ,Phantoms, Imaging ,Hypertrophic cardiomyopathy ,Reproducibility of Results ,Magnetic resonance imaging ,Cardiomyopathy, Hypertrophic ,Reference Standards ,medicine.disease ,Magnetic Resonance Imaging ,Confidence interval ,Multicenter study ,Quality assurance ,Standardization ,Clinical trial ,Cardiovascular and Metabolic Diseases ,Cardiology and Cardiovascular Medicine ,Nuclear medicine ,business - Abstract
Background Quantitative cardiovascular magnetic resonance T1-mapping is increasingly used for myocardial tissue characterization. However, the lack of standardization limits direct comparability between centers and wider roll-out for clinical use or trials. Purpose To develop a quality assurance (QA) program assuring standardized T1 measurements for clinical use. Methods MR phantoms manufactured in 2013 were distributed, including ShMOLLI T1-mapping and reference T1 and T2 protocols. We first studied the T1 and T2 dependency on temperature and phantom aging using phantom datasets from a single site over 4 years. Based on this, we developed a multiparametric QA model, which was then applied to 78 scans from 28 other multi-national sites. Results T1 temperature sensitivity followed a second-order polynomial to baseline T1 values (R2 > 0.996). Some phantoms showed aging effects, where T1 drifted up to 49% over 40 months. The correlation model based on reference T1 and T2, developed on 1004 dedicated phantom scans, predicted ShMOLLI-T1 with high consistency (coefficient of variation 1.54%), and was robust to temperature variations and phantom aging. Using the 95% confidence interval of the correlation model residuals as the tolerance range, we analyzed 390 ShMOLLI T1-maps and confirmed accurate sequence deployment in 90%(70/78) of QA scans across 28 multiple centers, and categorized the rest with specific remedial actions. Conclusions The proposed phantom QA for T1-mapping can assure correct method implementation and protocol adherence, and is robust to temperature variation and phantom aging. This QA program circumvents the need of frequent phantom replacements, and can be readily deployed in multicenter trials., Highlights • CMR T1 correlated with reference T1 and T2; this derives the QA model for T1-map. • The proposed QA model is robust to temperature variations and phantom aging. • This QA method requires no frequent phantom replacements. • The T1-map QA program can be readily deployed in multicenter trials.
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- 2021
12. Estimation of fractional myocardial blood volume and water exchange using ferumoxytol‐enhanced <scp>magnetic resonance imaging</scp>
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Caroline M Colbert, Aleksandra Radjenovic, Michael A. Thomas, Ran Yan, Kim-Lien Nguyen, J. Paul Finn, and Peng Hu
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Swine ,Haemodynamic response ,Contrast Media ,Blood volume ,Water exchange ,Cardiovascular ,Medical and Health Sciences ,Article ,030218 nuclear medicine & medical imaging ,swine model ,03 medical and health sciences ,Engineering ,0302 clinical medicine ,ferumoxytol ,Animals ,Medicine ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Heart Disease - Coronary Heart Disease ,tissue blood volume ,Blood Volume ,medicine.diagnostic_test ,business.industry ,Limits of agreement ,Reproducibility of Results ,Water ,Magnetic resonance imaging ,T1 mapping ,Magnetic Resonance Imaging ,Ferrosoferric Oxide ,Ferumoxytol ,Nuclear Medicine & Medical Imaging ,Heart Disease ,Relaxation rate ,Physical Sciences ,Biomedical Imaging ,business ,Nuclear medicine ,Perfusion ,compartment modeling - Abstract
BACKGROUND: Fractional myocardial blood volume (fMBV) estimated using ferumoxytol-enhanced MRI (FE-MRI) has the potential to capture a hemodynamic response to myocardial hypoperfusion during contrast steady state without reliance on gadolinium chelates. Ferumoxytol has a long intravascular half-life and its use for steady-state MRI is off-label. PURPOSE: To optimize and evaluate a two-compartment model for estimation of fMBV based on FE-MRI. STUDY TYPE: Prospective ANIMAL MODEL: Nine healthy swine; one swine with artificially-induced single-vessel coronary stenosis. FIELD STRENGTH/SEQUENCE: 3.0T clinical magnet using the 5(3)3(3)3 Modified Look-Locker Inversion Recovery (MOLLI) sequence. ASSESSMENT: Myocardial longitudinal spin-lattice relaxation rate (R1) was measured using the MOLLI sequence before and at contrast steady state following seven ferumoxytol infusions (0.125 – 4.0 mg/kg). fMBV and water exchange were estimated using a two-compartment model. Model-fitted fMBV was compared to simple fast-exchange fMBV approximation and percent change in pre and post-ferumoxytol R1. Dose under-sampling schemes were investigated to reduce acquisition duration. STATISTICAL TESTS: Variation in fMBV was assessed with a one-way analysis of variance (ANOVA). Fast-exchange fMBV and ferumoxytol dose under-sampling were evaluated using Bland-Altman analysis. RESULTS: Healthy normal swine showed a mean mid-ventricular fMBV of 7.2 ± 1.4% and water exchange rate of 11.3 ± 5.1 s(−1). There was inter-subject variation in fMBV (p
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- 2020
13. Comparing the interobserver reproducibility of different regions of interest on multi-parametric renal magnetic resonance imaging in healthy volunteers, patients with heart failure and renal transplant recipients
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Rosemary Woodward, Naveed Sattar, Bernd Kuehn, Aleksandra Radjenovic, G. Roditi, Sarah Allwood-Spiers, Patrick B. Mark, Keith Gillis, Matthew M.Y. Lee, Alastair J Rankin, and Luke Zhu
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Adult ,Male ,Intraclass correlation ,Coefficient of variation ,030232 urology & nephrology ,Biophysics ,Kidney Volume ,Renal MRI ,030204 cardiovascular system & hematology ,Kidney ,03 medical and health sciences ,0302 clinical medicine ,Chronic kidney disease ,Image Interpretation, Computer-Assisted ,medicine ,Humans ,Effective diffusion coefficient ,Radiology, Nuclear Medicine and imaging ,Multiparametric Magnetic Resonance Imaging ,Aged ,Heart Failure ,Observer Variation ,Reproducibility ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Reproducibility of Results ,Renal transplantation ,Magnetic resonance imaging ,Organ Size ,Middle Aged ,medicine.disease ,Kidney Transplantation ,Healthy Volunteers ,Diffusion Magnetic Resonance Imaging ,medicine.anatomical_structure ,Heart failure ,Female ,business ,Nuclear medicine ,Glomerular Filtration Rate ,Research Article - Abstract
Objective To assess interobserver reproducibility of different regions of interest (ROIs) on multi-parametric renal MRI using commercially available software. Materials and methods Healthy volunteers (HV), patients with heart failure (HF) and renal transplant recipients (Tx) were recruited. Localiser scans, T1 mapping and pseudo-continuous arterial spin labelling (pCASL) were performed. HV and Tx also underwent diffusion-weighted imaging to allow calculation of apparent diffusion coefficient (ADC). For T1, pCASL and ADC, ROIs were drawn for whole kidney (WK), cortex (Cx), user-defined representative cortex (rep-Cx) and medulla. Intraclass correlation coefficient (ICC) and coefficient of variation (CoV) were assessed. Results Forty participants were included (10 HV, 10 HF and 20 Tx). The ICC for renal volume was 0.97 and CoV 6.5%. For T1 and ADC, WK, Cx, and rep-Cx were highly reproducible with ICC ≥ 0.76 and CoV 0.86, but CoV up to 14.2%). While reproducible, WK values were derived from a wide spread of data (ROI standard deviation 17% to 55% of the mean value for ADC and pCASL, respectively). Renal volume differed between groups (p p = 0.009) and HF (p = 0.02). Medullary T1 values were also higher in Tx than HV (p = 0.03), while medullary pCASL values were significantly lower in Tx compared to HV and HF (p = 0.03 for both). Discussion Kidney volume calculated by manually contouring a localiser scan was highly reproducible between observers and detected significant differences across patient groups. For T1, pCASL and ADC, Cx and rep-Cx ROIs are generally reproducible with advantages over WK values.
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- 2019
14. Muscle Protein Synthesis and Muscle/Metabolic Responses To Resistance Exercise Training in South Asian and White European Men
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Stuart R. Gray, Lynsey Johnston, Aleksandra Radjenovic, Jason G. Gill, Faris F. Aba Aba Alkhayl, Paul P. Welsh, John Wilson, Carlos Celis-Morales, Tom Preston, Naveed Sattar, and Ahmad D. Ismail
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Adult ,Male ,South asia ,Muscle Proteins ,Physiology ,White People ,Young Adult ,Asian People ,Humans ,Medicine ,Muscle Strength ,Muscle, Skeletal ,Exercise ,Asia, Southeastern ,Muscle protein ,Multidisciplinary ,White (horse) ,business.industry ,Resistance training ,Resistance Training ,Lipid Metabolism ,Europe ,Adipose Tissue ,Body Composition ,Carbohydrate Metabolism ,Insulin Resistance ,business - Abstract
PurposeThe aims of the current study, therefore, were to compare 1) free-living MPS and 2) muscle and metabolic adaptations to resistance exercise in South Asian and white European adults.MethodsEighteen South Asian and 16 White European men were enrolled in the study. Free-living muscle protein synthesis was measured at baseline. Muscle strength, body composition, resting metabolic rate, VO2max and metabolic responses (insulin sensitivity) to a mixed meal were measured at baseline and following 12 weeks of resistance exercise training. Results Free-living muscle protein synthesis was not different between South Asians (1.48 ± 0.09 %/day) and White Europeans (1.59 ± 0.15 %/day) (p=0.522). In response to resistance exercise training there were no differences, between South Asians and White Europeans, muscle mass, lower body strength or insulin sensitivity. However, there were differences between the ethnicities in response to resistance exercise training in body fat, resting carbohydrate and fat metabolism, blood pressure, VO2max and upper body strength with responses less favourable in South Asians. ConclusionIn this exploratory study there were no differences in muscle protein synthesis or anabolic and metabolic responses to resistance exercise, yet there were less favourable responses in several outcomes. These findings require further investigation.
- Published
- 2021
15. Ferumoxytol magnetic resonance angiography: a dose-finding study in patients with chronic kidney disease
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Aleksandra Radjenovic, Martin Hennessy, Ram Kasthuri, David B. Kingsmore, Sokratis Stoumpos, Patrick B. Mark, Alex T. Vesey, and Giles Roditi
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Male ,medicine.medical_specialty ,Inferior vena cava ,Magnetic resonance angiography ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Chronic kidney disease ,medicine.artery ,Iron oxide ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Magnetic Resonance ,Prospective Studies ,Renal Insufficiency, Chronic ,Neuroradiology ,MR angiography ,Ferumoxytol ,Dose-Response Relationship, Drug ,medicine.diagnostic_test ,business.industry ,Abdominal aorta ,Magnetic resonance imaging ,Interventional radiology ,General Medicine ,Middle Aged ,medicine.disease ,Ferrosoferric Oxide ,medicine.vein ,030220 oncology & carcinogenesis ,Injections, Intravenous ,Hematinics ,cardiovascular system ,Female ,Radiology ,business ,Magnetic Resonance Angiography ,Kidney disease - Abstract
Objectives Ferumoxytol is an alternative to gadolinium-based compounds as a vascular contrast agent for magnetic resonance angiography (MRA), particularly for patients with chronic kidney disease (CKD). However, dose-related efficacy data are lacking. We aimed to determine the optimal (minimum effective) dose of ferumoxytol for MRA in patients with CKD. Methods Ferumoxytol-enhanced MRA (FeMRA) was performed at 3.0 T in patients with CKD after dose increments up to a total of 4 mg/kg. Image quality was assessed by contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) in the abdominal aorta and inferior vena cava. Quadratic regression analyses were performed to estimate the effects of dose increments on CNR and SNR. Results Twenty-three patients underwent FeMRA (mean age 60 [SD 13] years, 87% men, 48% had diabetic nephropathy) with cumulative doses of 0, 1, 2, 3 and 4 mg/kg of ferumoxytol. On regression analyses, a parabolic relationship was observed between ferumoxytol dose and signal with progressive signal loss using doses exceeding 4 mg/kg. A dose of 3 mg/kg achieved ≥ 75% of predicted peak CNR and SNR and images were deemed of excellent diagnostic quality. Conclusions In patients with CKD undergoing FeMRA, a dose of 3 mg/kg provides excellent arterial and venous enhancement. The benefits of increasing the dose to a theoretically optimal value of 4 mg/kg appear to be negligible and likely of minimal, if any, diagnostic value. Key Points • Ferumoxytol is used off-label as an MRI contrast agent but dose-related data are lacking. • In patients with CKD requiring MR angiography, a dose of 3 mg/kg provides excellent vascular enhancement. Electronic supplementary material The online version of this article (10.1007/s00330-019-06137-4) contains supplementary material, which is available to authorized users.
- Published
- 2019
16. Image‐based computational fluid dynamics for estimating pressure drop and fractional flow reserve across iliac artery stenosis: A comparison with in‐vivo measurements
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Giles Roditi, Aleksandra Radjenovic, Simeon Skopalik, Pauline Hall Barrientos, Patrick B. Mark, James Matthews, and Manosh C. Paul
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medicine.medical_specialty ,0206 medical engineering ,Biomedical Engineering ,Constriction, Pathologic ,02 engineering and technology ,Fractional flow reserve ,030204 cardiovascular system & hematology ,Computational fluid dynamics ,Coronary Angiography ,Iliac Artery ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Humans ,Medicine ,Molecular Biology ,Pressure drop ,medicine.diagnostic_test ,business.industry ,Applied Mathematics ,Coronary Stenosis ,Magnetic resonance imaging ,Gold standard (test) ,medicine.disease ,Coronary Vessels ,020601 biomedical engineering ,Fractional Flow Reserve, Myocardial ,Coronary arteries ,Stenosis ,medicine.anatomical_structure ,Computational Theory and Mathematics ,Modeling and Simulation ,Hydrodynamics ,Cardiology ,business ,Software ,Artery - Abstract
Computational Fluid Dynamics (CFD) and time‐resolved phase‐contrast magnetic resonance imaging (PC‐MRI) are potential non‐invasive methods for the assessment of the severity of arterial stenoses. Fractional flow reserve (FFR) is the current “gold standard” for determining stenosis severity in the coronary arteries but is an invasive method requiring insertion of a pressure wire. CFD derived FFR (vFFR) is an alternative to traditional catheter derived FFR now available commercially for coronary artery assessment, however, it can potentially be applied to a wider range of vulnerable vessels such as the iliac arteries. In this study CFD simulations are used to assess the ability of vFFR in predicting the stenosis severity in a patient with a stenosis of 77% area reduction (>50% diameter reduction) in the right iliac artery. Variations of vFFR, overall pressure drop and flow split between the vessels were observed by using different boundary conditions. Correlations between boundary condition parameters and resulting flow variables are presented. The study concludes that vFFR has good potential to characterise iliac artery stenotic disease.
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- 2021
17. Psoriatic arthritis is associated with adverse body composition predictive of greater coronary heart disease and type 2 diabetes propensity : a cross-sectional study
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Stefan Siebert, Olof Dahlqvist Leinhard, Pauline Hall Barrientos, Giles Roditi, Rosemary Woodward, Iain B. McInnes, Aleksandra Radjenovic, Jennifer Linge, Lyn D. Ferguson, and Naveed Sattar
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Male ,obesity ,Cross-sectional study ,Adipose tissue ,Coronary Disease ,Type 2 diabetes ,Gastroenterology ,0302 clinical medicine ,Weight loss ,Interquartile range ,Risk Factors ,Pharmacology (medical) ,Cardiac and Cardiovascular Systems ,030212 general & internal medicine ,AcademicSubjects/MED00360 ,psoriatic arthritis ,Kardiologi ,diabetes ,Age Factors ,Middle Aged ,Clinical Science ,Magnetic Resonance Imaging ,Prostate-specific antigen ,Liver ,Thigh ,Endokrinologi och diabetes ,Body Composition ,Female ,medicine.symptom ,Adult ,medicine.medical_specialty ,ectopic fat ,Intra-Abdominal Fat ,Endocrinology and Diabetes ,03 medical and health sciences ,Sex Factors ,Rheumatology ,Internal medicine ,Diabetes mellitus ,medicine ,Humans ,Muscle, Skeletal ,Aged ,030203 arthritis & rheumatology ,business.industry ,Arthritis, Psoriatic ,medicine.disease ,Obesity ,Cross-Sectional Studies ,CHD ,Diabetes Mellitus, Type 2 ,Case-Control Studies ,business - Abstract
Objectives To compare body composition in PsA with metabolic disease free (MDF) controls and type 2 diabetes and assess body-composition predicted propensity for cardiometabolic disease. Methods Detailed MRI body composition profiles of 26 PsA participants from the IMAPA study were compared with 130 age, sex and BMI-matched MDF controls and 454 individuals with type 2 diabetes from UK Biobank. The body-composition predicted propensity for coronary heart disease (CHD) and type 2 diabetes was compared between PsA and matched MDF controls. Results PsA participants had a significantly greater visceral adipose tissue (VAT) volume [mean 5.89 l (s.d. 2.10 l)] compared with matched-MDF controls [mean 4.34 l (s.d. 1.83 l)] (P Conclusion Individuals with PsA have an adverse body composition phenotype with greater visceral and ectopic liver fat and lower thigh muscle volume than matched MDF controls. Body fat distribution in PsA is more in keeping with the pattern observed in type 2 diabetes and is associated with greater propensity to cardiometabolic disease. These data support the need for greater emphasis on weight loss in PsA management to lessen CHD and type 2 diabetes risk.
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- 2021
18. Effect of Empagliflozin on Left Ventricular Volumes in Patients With Type 2 Diabetes, or Prediabetes, and Heart Failure With Reduced Ejection Fraction (SUGAR-DM-HF)
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Vera Lennie, Aleksandra Radjenovic, Victor Chong, Kirsty Wetherall, Steven Sourbron, Naveed Sattar, Colin J. Petrie, Liz Coyle, Catherine Labinjoh, Katriona Brooksbank, Giles Roditi, John J.V. McMurray, Matthew M.Y. Lee, Rosemary Woodward, John R. Petrie, Iain A. Speirits, John G. Dreisbach, Clare Murphy, Pardeep S. Jhund, Kieran F. Docherty, Colin Berry, Alex McConnachie, Paul Welsh, Kenneth Mangion, Patrick B. Mark, Ross T. Campbell, Mark C. Petrie, and Ninian N. Lang
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Male ,medicine.medical_specialty ,Type 2 diabetes ,030204 cardiovascular system & hematology ,Prediabetic State ,03 medical and health sciences ,0302 clinical medicine ,Double-Blind Method ,Glucosides ,Physiology (medical) ,Internal medicine ,Diabetes mellitus ,medicine ,Empagliflozin ,Humans ,030212 general & internal medicine ,Prediabetes ,Benzhydryl Compounds ,Ventricular remodeling ,Sodium-Glucose Transporter 2 Inhibitors ,Aged ,Heart Failure ,Ejection fraction ,medicine.diagnostic_test ,Ventricular Remodeling ,business.industry ,Magnetic resonance imaging ,Stroke Volume ,medicine.disease ,Diabetes Mellitus, Type 2 ,Heart failure ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background: Sodium-glucose cotransporter 2 inhibitors reduce the risk of heart failure hospitalization and cardiovascular death in patients with heart failure and reduced ejection fraction (HFrEF). However, their effects on cardiac structure and function in HFrEF are uncertain. Methods: We designed a multicenter, randomized, double-blind, placebo-controlled trial (the SUGAR-DM-HF trial [Studies of Empagliflozin and Its Cardiovascular, Renal and Metabolic Effects in Patients With Diabetes Mellitus, or Prediabetes, and Heart Failure]) to investigate the cardiac effects of empagliflozin in patients in New York Heart Association functional class II to IV with a left ventricular (LV) ejection fraction ≤40% and type 2 diabetes or prediabetes. Patients were randomly assigned 1:1 to empagliflozin 10 mg once daily or placebo, stratified by age ( Results: From April 2018 to August 2019, 105 patients were randomly assigned: mean age 68.7 (SD, 11.1) years, 77 (73.3%) male, 82 (78.1%) diabetes and 23 (21.9%) prediabetes, mean LV ejection fraction 32.5% (9.8%), and 81 (77.1%) New York Heart Association II and 24 (22.9%) New York Heart Association III. Patients received standard treatment for HFrEF. In comparison with placebo, empagliflozin reduced LV end-systolic volume index by 6.0 (95% CI, –10.8 to –1.2) mL/m 2 ( P =0.015). There was no difference in LV global longitudinal strain. Empagliflozin reduced LV end-diastolic volume index by 8.2 (95% CI, –13.7 to –2.6) mL/m 2 ( P =0.0042) and reduced N-terminal pro-B-type natriuretic peptide by 28% (2%–47%), P =0.038. There were no between-group differences in other cardiovascular magnetic resonance measures, diuretic intensification, Kansas City Cardiomyopathy Questionnaire Total Symptom Score, 6-minute walk distance, or B-lines. Conclusions: The sodium-glucose cotransporter 2 inhibitor empagliflozin reduced LV volumes in patients with HFrEF and type 2 diabetes or prediabetes. Favorable reverse LV remodeling may be a mechanism by which sodium-glucose cotransporter 2 inhibitors reduce heart failure hospitalization and mortality in HFrEF. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT03485092.
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- 2021
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19. Vascular effects of serelaxin in patients with stable coronary artery disease: a randomized placebo-controlled trial
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Markus Hinder, Ify Mordi, Simon Wilson, Aleksandra Radjenovic, Surendra Machineni, Iain B. Squire, David E. Newby, Niko Tzemos, Margaret F. Prescott, Gerry P McCann, Scott Semple, Sheraz A Nazir, Denise Yates, Jose Alcantara, Barbara Gugliotta, David Corcoran, Yinuo Pang, and Colin Berry
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Male ,Physiology ,Vasodilator Agents ,Placebo-controlled study ,Coronary Artery Disease ,030204 cardiovascular system & hematology ,030226 pharmacology & pharmacy ,Coronary artery disease ,0302 clinical medicine ,Medicine ,AcademicSubjects/MED00200 ,Prospective Studies ,Pulse wave velocity ,Vascular Pathophysiology ,Troponin T ,Relaxin ,Aortic stiffness ,Myocardial Perfusion Imaging ,Middle Aged ,Recombinant Proteins ,Vasodilation ,Treatment Outcome ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,Perfusion ,medicine.medical_specialty ,Manometry ,Magnetic Resonance Imaging, Cine ,Pulse Wave Analysis ,Placebo ,03 medical and health sciences ,Myocardial perfusion ,Vascular Stiffness ,Double-Blind Method ,Serelaxin ,Physiology (medical) ,Internal medicine ,Coronary Circulation ,Humans ,Arterial Pressure ,Aged ,business.industry ,Original Articles ,medicine.disease ,United Kingdom ,Blood pressure ,business ,Biomarkers - Abstract
Aims The effects of serelaxin, a recombinant form of human relaxin-2 peptide, on vascular function in the coronary microvascular and systemic macrovascular circulation remain largely unknown. This mechanistic, clinical study assessed the effects of serelaxin on myocardial perfusion, aortic stiffness, and safety in patients with stable coronary artery disease (CAD). Methods and results In this multicentre, double-blind, parallel-group, placebo-controlled study, 58 patients were randomized 1:1 to 48 h intravenous infusion of serelaxin (30 µg/kg/day) or matching placebo. The primary endpoints were change from baseline to 47 h post-initiation of the infusion in global myocardial perfusion reserve (MPR) assessed using adenosine stress perfusion cardiac magnetic resonance imaging, and applanation tonometry-derived augmentation index (AIx). Secondary endpoints were: change from baseline in AIx and pulse wave velocity, assessed at 47 h, Day 30, and Day 180; aortic distensibility at 47 h; pharmacokinetics and safety. Exploratory endpoints were the effect on cardiorenal biomarkers [N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hsTnT), endothelin-1, and cystatin C]. Of 58 patients, 51 were included in the primary analysis (serelaxin, n = 25; placebo, n = 26). After 2 and 6 h of serelaxin infusion, mean placebo-corrected blood pressure reductions of −9.6 mmHg (P = 0.01) and −13.5 mmHg (P = 0.0003) for systolic blood pressure and −5.2 mmHg (P = 0.02) and −8.4 mmHg (P = 0.001) for diastolic blood pressure occurred. There were no between-group differences from baseline to 47 h in global MPR (−0.24 vs. −0.13, P = 0.44) or AIx (3.49% vs. 0.04%, P = 0.21) with serelaxin compared with placebo. Endothelin-1 and cystatin C levels decreased from baseline in the serelaxin group, and there were no clinically relevant changes observed with serelaxin for NT-proBNP or hsTnT. Similar numbers of serious adverse events were observed in both groups (serelaxin, n = 5; placebo, n = 7) to 180-day follow-up. Conclusion In patients with stable CAD, 48 h intravenous serelaxin reduced blood pressure but did not alter myocardial perfusion.
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- 2021
20. Cardiovascular magnetic resonance for the detection of descending thoracic aorta calcification in patients with end-stage renal disease
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Ioannis Koktzoglou, Sokratis Stoumpos, Patrick B. Mark, Pauline Hall Barrientos, Rosemary Woodward, Jennifer S Lees, Alastair J Rankin, Aleksandra Radjenovic, Robert R. Edelman, Elbert Edy, and Giles Roditi
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medicine.medical_specialty ,Magnetic Resonance Spectroscopy ,Thoracic aorta calcification ,Aorta, Thoracic ,Coronary Artery Disease ,030204 cardiovascular system & hematology ,End stage renal disease ,03 medical and health sciences ,End-stage renal disease ,0302 clinical medicine ,Predictive Value of Tests ,Thoracic aortic calcification ,medicine.artery ,medicine ,Thoracic aorta ,Diseases of the circulatory (Cardiovascular) system ,Humans ,Radiology, Nuclear Medicine and imaging ,Radial volumetric interpolated breath-hold examination (radial-VIBE) sequence ,cardiovascular diseases ,Prospective Studies ,Computed tomography ,030304 developmental biology ,Angiology ,0303 health sciences ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Research ,Magnetic resonance imaging ,medicine.disease ,Cardiovascular disease ,Magnetic Resonance Imaging ,Descending aorta ,RC666-701 ,cardiovascular system ,Kidney Failure, Chronic ,Cardiology and Cardiovascular Medicine ,Agatston score ,Nuclear medicine ,business ,Calcification - Abstract
Background Vascular calcification is an independent predictor of cardiovascular disease in patients with chronic kidney disease. Computed tomography (CT) is the gold-standard for detecting vascular calcification. Radial volumetric-interpolated breath-hold examination (radial-VIBE), a free-breathing gradient-echo cardiovascular magnetic resonance (CMR) sequence, has advantages over CT as it is ionising radiation-free. However, its capability in detecting thoracic aortic calcification (TAC) has not been investigated. This study aims to compare radial-VIBE to CT for the detection of TAC in the descending aorta of patients with end-stage renal disease (ESRD) using semi-automated methods, and to investigate the association between TAC and coronary artery calcification (CAC). Methods Paired cardiac CT and radial-VIBE CMR scans from ESRD patients participating in 2 prospective studies were obtained. Calcification volume was quantified using semi-automated methods in a 9 cm segment of the thoracic aorta. Correlation and agreement between TAC volume measured on CMR and CT were assessed with Spearman’s correlation coefficient (ρ), linear regression, Bland–Altman plots and intraclass correlation coefficient (ICC). Association between CAC Agatston score and TAC volume determined by CT and CMR was measured with Spearman’s correlation coefficient. Results Scans from 96 participants were analysed. Positive correlation was found between CMR and CT calcification volume [ρ = 0.61, 95% confidence interval (CI) 0.45–0.73]. ICC for consistency was 0.537 (95% CI 0.378–0.665). Bland–Altman plot revealed that compared to CT, CMR volumes were systematically higher at low calcification volume, and lower at high calcification volume. CT did not detect calcification in 41.7% of participants, while radial-VIBE CMR detected signal which the semi-quantitative algorithm reported as calcification in all of those individuals. Instances of suboptimal radial-VIBE CMR image quality were deemed to be the major contributors to the discrepancy. Correlations between CAC Agatston score and TAC volume measured by CT and CMR were ρ = 0.404 (95% CI 0.214–0.565) and ρ = 0.211 (95% CI 0.008–0.396), respectively. Conclusion Radial-VIBE CMR can detect TAC with strong positive association to CT, albeit with the presence of proportional bias. Quantification of vascular calcification by radial-VIBE remains a promising area for future research, but improvements in image quality are necessary.
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- 2020
21. Ferumoxytol MR Angiography versus Duplex US for Vascular Mapping before Arteriovenous Fistula Surgery for Hemodialysis
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Giles Roditi, David B. Kingsmore, Ram Kasthuri, Karen Stevenson, Alfred Tan, Pauline Hall Barrientos, Aleksandra Radjenovic, Peter C. Thomson, Sokratis Stoumpos, and Patrick B. Mark
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Male ,medicine.medical_specialty ,medicine.medical_treatment ,Arteriovenous fistula ,Contrast Media ,Magnetic resonance angiography ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Arteriovenous Shunt, Surgical ,Renal Dialysis ,medicine ,Vascular Patency ,Humans ,Radiology, Nuclear Medicine and imaging ,Ultrasonography, Doppler, Duplex ,medicine.diagnostic_test ,business.industry ,Mr angiography ,Middle Aged ,medicine.disease ,Ferrosoferric Oxide ,Surgery ,Ferumoxytol ,Stenosis ,Duplex (building) ,030220 oncology & carcinogenesis ,Female ,Hemodialysis ,business ,Algorithms ,Magnetic Resonance Angiography - Abstract
Background Duplex US is performed routinely for vascular mapping prior to arteriovenous fistula (AVF) creation for hemodialysis but cannot demonstrate the central vasculature. Ferumoxytol, an iron oxide nanoparticle, provides an alternative to gadolinium contrast material for MR angiography for safe use in chronic kidney disease (CKD). Purpose To assess the clinical utility of ferumoxytol-enhanced MR angiography compared with duplex US for vascular mapping before upper limb AVF creation in participants with CKD. Materials and Methods In a prospective comparative study (ClinicalTrials.gov: NCT02997046) from December 2016 to August 2018, participants with CKD underwent ferumoxytol-enhanced MR angiography and duplex US. Two independent readers evaluated vessels for diameter, stenosis or occlusion, arterial disease, and central stenosis. Intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to assess intra- and interreader variability. On the basis of accepted standards for AVF creation, an algorithm was developed to predict AVF outcome based on imaging findings. Multivariable regression models used AVF success as the dependent variable and age, sex, and duplex US or ferumoxytol-enhanced MR angiography findings as independent variables. Results Fifty-nine participants with CKD (mean age, 59 years ± 13 [standard deviation]; 30 women) were evaluated. A total of 51 fistulas were created, of which 24 (47%) were successful. Ferumoxytol-enhanced MR angiography showed excellent inter- and intrareader repeatability (ICC, 0.84-0.99) for all variables assessed. In addition to revealing 15 central vasculature stenoses, ferumoxytol-enhanced MR angiography resulted in characterization of 88 of 236 (37%) of the arterial sections examined as unsuitable for AVF creation compared with 61 of 236 (26%) sections with duplex US (
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- 2020
22. P0289MULTI-PARAMETRIC RENAL MAGNETIC RESONANCE IMAGING IN EARLY KIDNEY TRANSPLANTATION
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Rosemary Woodward, Aleksandra Radjenovic, G. Roditi, Rajan K. Patel, Bernd Kuehn, Patrick B. Mark, Keith Gillis, Sarah Allwood-Spiers, and Alastair J Rankin
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Transplantation ,medicine.medical_specialty ,medicine.diagnostic_test ,Nephrology ,business.industry ,medicine ,Magnetic resonance imaging ,Radiology ,medicine.disease ,business ,Kidney transplantation ,Parametric statistics - Abstract
Background and Aims Existing methods of investigating renal transplant dysfunction do not provide reliable information regarding diagnosis nor prognosis. Multi-parametric magnetic resonance imaging (MRI) may provide novel biomarkers for evaluation of transplant dysfunction. We aim to determine how MRI parameters change over the first year of transplantation, and how these relate to future renal function. Method Patients receiving a kidney transplant attended for study visits at 6, 26 and 52 weeks post operatively, comprising measurement of clinical and biochemical parameters, together with research multi-parametric MRI. Imaging measurements comprised kidney volume, arterial spin labelling (ASL) perfusion, T1 relaxation time, T2*, apparent diffusion coefficient (ADC) and fractional anisotropy (FA). Imaging was performed at 3.0 Tesla using a Siemens MAGNETOM Prisma system. Regions of interest were drawn in whole kidney (WK), cortex (Cx) and medulla (Md) (figure 1). Results 20 patients were included: 16 were male, with age 55.5±12.8 years, baseline eGFR 54.0±23.6 ml/min/1.73m2, and blood pressure 146/80 ± 15/15 mmHg. 14 received deceased, and 6 received live, donor transplants. Patients were all managed with tacrolimus, mycophenolate and low dose prednisolone, following induction therapy with either basiliximab or anti-thymocyte globulin. 6 week ADC was 1.69±0.14 in WK, 1.65±0.08 in Cx, and 1.67±0.10 ×10-3 mm2/s in Md. FA was 0.19±0.04 in WK, 0.14 ± 0.04 in Cx and 0.22 ± 0.10 in Md. T2* was 57.6±9.4 in WK, 63.9±8.7 in Cx and 45.0±8.0 ms in Md. Over the 3 visits there was reduction in FA (p=0.008) and medullary T2* (p Over 1 year the median change in eGFR was -2ml/min/1.73m2. There was correlation between baseline eGFR and the following variables: volume (r=0.29, p=0.04), whole kidney ADC (r=0.36, p=0.01), cortical ADC (r=0.46, p=0.001), representative cortex ADC (r=0.48, p Conclusion Diffusion weighted MRI measurements correlate with eGFR and may allow improved prognostication regarding future renal function. Certain MRI parameters including FA and R2* vary depending on time point of transplantation which may reflect changes in transplant microstructure in the early postoperative period. Multi-parametric MRI provides a novel method of evaluating renal transplants non-invasively and may allow more accurate prediction of future transplant function than existing biochemical measures.
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- 2020
23. Use of Ferumoxytol enhanced Magnetic Resonance Angiography for cardiovascular assessment in late-stage chronic kidney disease
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Sokratis Stoumpos, Patrick Mark, David Kingsmore, Giles Roditi, and Aleksandra Radjenovic
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- 2020
24. Hypertension, Microvascular Pathology, and Prognosis After an Acute Myocardial Infarction
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Ian Ford, Colin Berry, Vannesa Teng Yue May, Ify Mordi, Jaclyn Carberry, David Carrick, Keith G. Oldroyd, Paul Welsh, Aleksandra Radjenovic, Naveed Sattar, Stuart Hood, Mitchell Lindsay, Annette Maznyczka, Andrew Davie, Kenneth Mangion, Nadeem Ahmed, Margaret McEntegart, Hany Eteiba, Stuart Watkins, Caroline Haig, Mark C. Petrie, Kirsty Wetherall, and Ahmed Mahrous
- Subjects
Male ,medicine.medical_specialty ,hypertension ,030204 cardiovascular system & hematology ,Microvascular injury ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Internal Medicine ,medicine ,Humans ,In patient ,030212 general & internal medicine ,Myocardial infarction ,Aged ,business.industry ,Age Factors ,Heart ,Original Articles ,Middle Aged ,reperfusion injury ,Prognosis ,medicine.disease ,Magnetic Resonance Imaging ,Pathophysiology ,myocardial infarction ,Logistic Models ,Microvessels ,Multivariate Analysis ,ComputingMethodologies_DOCUMENTANDTEXTPROCESSING ,Cardiology ,ST Elevation Myocardial Infarction ,Female ,atherosclerosis ,business ,Reperfusion injury - Abstract
Supplemental Digital Content is available in the text., The rationale for our study was to investigate the pathophysiology of microvascular injury in patients with acute ST-segment–elevation myocardial infarction in relation to a history of hypertension. We undertook a cohort study using invasive and noninvasive measures of microvascular injury, cardiac magnetic resonance imaging at 2 days and 6 months, and assessed health outcomes in the longer term. Three hundred twenty-four patients with acute myocardial infarction (mean age, 59 [12] years; blood pressure, 135 [25] / 79 [14] mm Hg; 237 [73%] male, 105 [32%] with antecedent hypertension) were prospectively enrolled during emergency percutaneous coronary intervention. Compared with patients without antecedent hypertension, patients with hypertension were older (63 [12] years versus 57 [11] years; P
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- 2018
25. Multicenter Safety and Practice for Off-Label Diagnostic Use of Ferumoxytol in MRI
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Mark L. Schiebler, Kim-Lien Nguyen, Csanad Varallyay, J. Paul Finn, Mark A. Fogel, Islam H Zaki, Mustafa R. Bashir, Giles Roditi, Kevin K. Whitehead, Michael D. Hope, Scott Semple, Lindsay M. Griffin, Aleksandra Radjenovic, Cynthia K. Rigsby, Martin R. Prince, Edward A. Neuwelt, David Saloner, David E. Newby, Rola Saouaf, Peng Hu, Takegawa Yoshida, Sokratis Stoumpos, and Nikhita Kathuria-Prakash
- Subjects
Male ,Contrast Media ,Off-label use ,Medical and Health Sciences ,030218 nuclear medicine & medical imaging ,0302 clinical medicine ,80 and over ,Registries ,Child ,Original Research ,Aged, 80 and over ,medicine.diagnostic_test ,Common Terminology Criteria for Adverse Events ,Middle Aged ,Magnetic Resonance Imaging ,Nuclear Medicine & Medical Imaging ,6.1 Pharmaceuticals ,030220 oncology & carcinogenesis ,Child, Preschool ,Female ,Patient Safety ,Adult ,medicine.medical_specialty ,Adolescent ,Drug-Related Side Effects and Adverse Reactions ,Vital signs ,Postmarketing surveillance ,03 medical and health sciences ,Clinical Research ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Preschool ,Adverse effect ,Nutrition ,Aged ,business.industry ,Infant, Newborn ,Evaluation of treatments and therapeutic interventions ,Infant ,Magnetic resonance imaging ,Off-Label Use ,Newborn ,medicine.disease ,Ferrosoferric Oxide ,Ferumoxytol ,Iron-deficiency anemia ,business - Abstract
BACKGROUND: Ferumoxytol is approved for use in the treatment of iron deficiency anemia, but it can serve as an alternative to gadolinium-based contrast agents. On the basis of postmarketing surveillance data, the Food and Drug Administration issued a black box warning regarding the risks of rare but serious acute hypersensitivity reactions during fast high-dose injection (510 mg iron in 17 seconds) for therapeutic use. Whereas single-center safety data for diagnostic use have been positive, multicenter data are lacking. PURPOSE: To report multicenter safety data for off-label diagnostic ferumoxytol use. MATERIALS AND METHODS: The multicenter ferumoxytol MRI registry was established as an open-label nonrandomized surveillance databank without industry involvement. Each center monitored all ferumoxytol administrations, classified adverse events (AEs) using the National Cancer Institute Common Terminology Criteria for Adverse Events (grade 1–5), and assessed the relationship of AEs to ferumoxytol administration. AEs related to or possibly related to ferumoxytol injection were considered adverse reactions. The core laboratory adjudicated the AEs and classified them with the American College of Radiology (ACR) classification. Analysis of variance was used to compare vital signs. RESULTS: Between January 2003 and October 2018, 3215 patients (median age, 58 years; range, 1 day to 96 years; 1897 male patients) received 4240 ferumoxytol injections for MRI. Ferumoxytol dose ranged from 1 to 11 mg per kilogram of body weight (≤510 mg iron; rate ≤45 mg iron/sec). There were no systematic changes in vital signs after ferumoxytol administration (P > .05). No severe, life-threatening, or fatal AEs occurred. Eighty-three (1.9%) of 4240 AEs were related or possibly related to ferumoxytol infusions (75 mild [1.8%], eight moderate [0.2%]). Thirty-one AEs were classified as allergiclike reactions using ACR criteria but were consistent with minor infusion reactions observed with parenteral iron. CONCLUSION: Diagnostic ferumoxytol use was well tolerated, associated with no serious adverse events, and implicated in few adverse reactions. Registry results indicate a positive safety profile for ferumoxytol use in MRI. © RSNA, 2019 Online supplemental material is available for this article.
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- 2019
26. Low-Dose Alteplase During Primary Percutaneous Coronary Intervention According to Ischemic Time
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Matthias Schmitt, Paul Welsh, Hany Eteiba, Elisa McAlindon, Campbell Tait, Naveed Sattar, Annette Maznyczka, Neil Maredia, Alex McConnachie, Peter McCartney, Colin Berry, Aleksandra Radjenovic, Vanessa Orchard, John P Greenwood, Keith G. Oldroyd, Timothy A. Fairbairn, Ian Ford, Gerry P McCann, Thomas J. Ford, Margaret McEntegart, David Corcoran, and T-Time Investigators
- Subjects
Male ,Time Factors ,Heart disease ,medicine.medical_treatment ,microvascular obstruction ,Myocardial Ischemia ,Ischemic time ,030204 cardiovascular system & hematology ,AUC, area under the curve ,0302 clinical medicine ,CMR, cardiac magnetic resonance ,Medicine ,Thrombolytic Therapy ,030212 general & internal medicine ,Myocardial infarction ,Prospective Studies ,STEMI, ST-segment elevation myocardial infarction ,myocardial hemorrhage ,Darkness ,Middle Aged ,primary percutaneous coronary intervention ,Tissue Plasminogen Activator ,Cardiology ,MI, myocardial infarction ,fibrinolysis ,Female ,Cardiology and Cardiovascular Medicine ,medicine.medical_specialty ,MVO, microvascular obstruction ,Placebo ,TIMI, Thrombolysis In Myocardial Infarction ,Article ,Time ,PPCI, primary percutaneous coronary intervention ,03 medical and health sciences ,Percutaneous Coronary Intervention ,Double-Blind Method ,Fibrinolytic Agents ,Internal medicine ,Fibrinolysis ,Humans ,IQR, interquartile range ,Aged ,Dose-Response Relationship, Drug ,business.industry ,Percutaneous coronary intervention ,medicine.disease ,ST-segment elevation myocardial infarction ,OR, odds ratio ,Conventional PCI ,Adjunctive treatment ,ST Elevation Myocardial Infarction ,business - Abstract
Background Microvascular obstruction affects one-half of patients with ST-segment elevation myocardial infarction and confers an adverse prognosis. Objectives This study aimed to determine whether the efficacy and safety of a therapeutic strategy involving low-dose intracoronary alteplase infused early after coronary reperfusion associates with ischemic time. Methods This study was conducted in a prospective, multicenter, parallel group, 1:1:1 randomized, dose-ranging trial in patients undergoing primary percutaneous coronary intervention. Ischemic time, defined as the time from symptom onset to coronary reperfusion, was a pre-specified subgroup of interest. Between March 17, 2016, and December 21, 2017, 440 patients, presenting with ST-segment elevation myocardial infarction within 6 h of symptom onset (, Central Illustration
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- 2019
27. 6030Effects of adjunctive treatment with low-dose alteplase during primary percutaneous coronary intervention according to ischaemic time
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Elisa McAlindon, N Maredia, Matthias Schmitt, Annette Maznyczka, Keith G. Oldroyd, Peter McCartney, John P Greenwood, T A Fairbairn, Aleksandra Radjenovic, Vanessa Orchard, Alex McConnachie, Colin Berry, Gerry P McCann, Hany Eteiba, and Margaret McEntegart
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medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Adjunctive treatment ,Low dose ,Medicine ,Percutaneous coronary intervention ,Cardiology and Cardiovascular Medicine ,business ,Surgery - Abstract
Background Microvascular obstruction affects half of patients with acute ST-segment elevation myocardial infarction and confers an adverse prognosis. Purpose We aimed to determine whether the efficacy and safety of a therapeutic strategy involving low-dose intra-coronary alteplase infused early after coronary reperfusion associates with ischaemic time. Methods We conducted a prospective, multicentre, parallel group, 1:1:1 randomised, dose-ranging trial in patients undergoing primary percutaneous coronary intervention. Ischaemic time, defined as the time from symptom onset to coronary reperfusion, was a pre-specified sub-group of interest. Between March 17, 2016, and December 21, 2017, 440 patients presenting at 11 hospitals in the UK were enrolled with follow up to 3 months. Patients with acute myocardial infarction due to occlusion of a major coronary artery presenting ≤6 hours from symptom onset were randomly assigned to treatment with placebo, alteplase 10mg or alteplase 20mg. The primary outcome was the amount of microvascular obstruction disclosed by cardiac magnetic resonance imaging at 2–7 days. Secondary outcomes included infarct size, myocardial haemorrhage, left ventricular ejection fraction, and troponin T area-under-the curve. Results 440 patients were randomized (figure), the primary endpoint was achieved in 396 (90%), seventeen (3.9%) withdrew and all other patients were followed up to 3 months. In the primary analysis, the amount of microvascular obstruction did not differ between the groups. Their ischaemic times were: ≤2 hours, n=98; ≥2– In patients with an ischaemic time ≥4 hours, treatment with alteplase (10 mg, n=26; 20 mg, n=30) was associated with a dose dependent increase in the amount (mean) of microvascular obstruction (% left ventricular mass) compared to placebo (n=27) 1.14 vs. 3.11 vs. 5.20; mean difference on square root scale 0.81 (95% CI 0.21, 1.42), p=0.009. The interaction test between ischaemic time and treatment (active vs. placebo) was not statistically significant p=0.06, however when the interaction was assessed for a trend across treatment groups this did reach statistical significance, p=0.018. Furthermore, a higher proportion of patients presenting ≥4–6 hours treated with 20 mg of alteplase had myocardial haemorrhage (59.3%) compared to the placebo group (28.0%), odds ratio 3.81 (95% CI 1.19, 12.25), p=0.025. The amount of haemorrhage was also greater; estimated mean difference 3.49 (95% CI 1.22, 5.75), p=0.0026. No between-treatment group differences for myocardial haemorrhage were observed in patients presenting with shorter ischaemic times. Study flow diagram Conclusions In patients presenting with an ischaemic time ≥4 hours, adjunctive treatment with low-dose intra-coronary alteplase during primary PCI was associated with increases in microvascular obstruction and myocardial haemorrhage. The mechanism may involve haemorrhagic transformation within the infarct core. Acknowledgement/Funding NIHR EME programme (reference: 12/170/45); British Heart Foundation (BHF reference FS/16/74/32573)
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- 2019
28. Ferumoxytol MR Angiography
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William Strauss, David B. Kingsmore, Pauline Hall Barrientos, Sokratis Stoumpos, Alex T. Vesey, Martin Hennessy, Patrick B. Mark, Giles Roditi, Douglas H. Black, Aleksandra Radjenovic, Karen Stevenson, and Ram Kasthuri
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Novel technique ,medicine.medical_specialty ,medicine.diagnostic_test ,urogenital system ,business.industry ,Mr angiography ,030204 cardiovascular system & hematology ,medicine.disease ,Kidney transplant ,030218 nuclear medicine & medical imaging ,Peripheral ,Ferumoxytol ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Radiology, Nuclear Medicine and imaging ,Radiology ,Cardiology and Cardiovascular Medicine ,business ,Kidney transplantation ,Kidney disease ,Computed tomography angiography - Abstract
Although kidney transplantation is the treatment of choice for suitable patients with end-stage kidney disease, approximately 25% of chronic kidney disease (CKD) patients have peripheral arterial disease (PAD) ([1][1]). Computed tomography angiography (CTA) can identify patients requiring
- Published
- 2020
29. Ferumoxytol MR Angiography: A Novel Technique for Assessing Iliac Vasculature in Potential Kidney Transplant Recipients
- Author
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Sokratis, Stoumpos, Pauline, Hall Barrientos, Douglas H, Black, Karen, Stevenson, Martin, Hennessy, Alex T, Vesey, William, Strauss, Ram, Kasthuri, Aleksandra, Radjenovic, David B, Kingsmore, Giles, Roditi, and Patrick B, Mark
- Subjects
Predictive Value of Tests ,Contrast Media ,Humans ,Kidney Transplantation ,Ferrosoferric Oxide ,Magnetic Resonance Angiography - Published
- 2019
30. FO019FERUMOXYTOL MR ANGIOGRAPHY VS DOPPLER US FOR VASCULAR MAPPING BEFORE HAEMODIALYSIS ARTERIOVENOUS ACCESS CREATION
- Author
-
Alfred Tan, Ram Kasthuri, David B. Kingsmore, Martin Hennessy, Aleksandra Radjenovic, Giles Roditi, Sokratis Stoumpos, and Patrick B. Mark
- Subjects
Transplantation ,medicine.medical_specialty ,Nephrology ,business.industry ,Mr angiography ,Medicine ,Doppler ultrasound ,Radiology ,business - Published
- 2019
31. FO039FERUMOXYTOL MR ANGIOGRAPHY VS CT ANGIOGRAPHY FOR THE ASSESSMENT OF POTENTIAL KIDNEY TRANSPLANT RECIPIENTS
- Author
-
Alex Vesey, Martin Hennessy, Sokratis Stoumpos, Aleksandra Radjenovic, Patrick B. Mark, Pauline Hall Barrientos, Ram Kasthuri, Douglas H. Black, David B. Kingsmore, Giles Roditi, and Karen S. Stevenson
- Subjects
Computed tomographic angiography ,Transplantation ,medicine.medical_specialty ,medicine.diagnostic_test ,Nephrology ,business.industry ,Angiography ,Mr angiography ,medicine ,Radiology ,business ,Kidney transplant - Published
- 2019
32. Quantitative Myocardial Perfusion Imaging Versus Visual Analysis in Diagnosing Myocardial Ischemia
- Author
-
Montasir Ibraheem, John D Biglands, John P Greenwood, Derek R. Magee, Aleksandra Radjenovic, and Sven Plein
- Subjects
medicine.medical_specialty ,education.field_of_study ,medicine.diagnostic_test ,business.industry ,Population ,Magnetic resonance imaging ,Perfusion scanning ,Blood flow ,030204 cardiovascular system & hematology ,medicine.disease ,Confidence interval ,030218 nuclear medicine & medical imaging ,Coronary artery disease ,03 medical and health sciences ,Myocardial perfusion imaging ,0302 clinical medicine ,Internal medicine ,medicine ,Cardiology ,Radiology, Nuclear Medicine and imaging ,Cardiology and Cardiovascular Medicine ,education ,business ,Perfusion - Abstract
Objectives This study sought to compare the diagnostic accuracy of visual and quantitative analyses of myocardial perfusion cardiovascular magnetic resonance against a reference standard of quantitative coronary angiography. Background Visual analysis of perfusion cardiovascular magnetic resonance studies for assessing myocardial perfusion has been shown to have high diagnostic accuracy for coronary artery disease. However, only a few small studies have assessed the diagnostic accuracy of quantitative myocardial perfusion. Methods This retrospective study included 128 patients randomly selected from the CE-MARC (Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease) study population such that the distribution of risk factors and disease status was proportionate to the full population. Visual analysis results of cardiovascular magnetic resonance perfusion images, by consensus of 2 expert readers, were taken from the original study reports. Quantitative myocardial blood flow estimates were obtained using Fermi-constrained deconvolution. The reference standard for myocardial ischemia was a quantitative coronary x-ray angiogram stenosis severity of ≥70% diameter in any coronary artery of >2 mm diameter, or ≥50% in the left main stem. Diagnostic performance was calculated using receiver-operating characteristic curve analysis. Results The area under the curve for visual analysis was 0.88 (95% confidence interval: 0.81 to 0.95) with a sensitivity of 81.0% (95% confidence interval: 69.1% to 92.8%) and specificity of 86.0% (95% confidence interval: 78.7% to 93.4%). For quantitative stress myocardial blood flow the area under the curve was 0.89 (95% confidence interval: 0.83 to 0.96) with a sensitivity of 87.5% (95% confidence interval: 77.3% to 97.7%) and specificity of 84.5% (95% confidence interval: 76.8% to 92.3%). There was no statistically significant difference between the diagnostic performance of quantitative and visual analyses (p = 0.72). Incorporating rest myocardial blood flow values to generate a myocardial perfusion reserve did not significantly increase the quantitative analysis area under the curve (p = 0.79). Conclusions Quantitative perfusion has a high diagnostic accuracy for detecting coronary artery disease but is not superior to visual analysis. The incorporation of rest perfusion imaging does not improve diagnostic accuracy in quantitative perfusion analysis.
- Published
- 2018
33. Current Smoking and Prognosis After Acute ST-Segment Elevation Myocardial Infarction: New Pathophysiological Insights
- Author
-
Caroline, Haig, David, Carrick, Jaclyn, Carberry, Kenneth, Mangion, Annette, Maznyczka, Kirsty, Wetherall, Margaret, McEntegart, Mark C, Petrie, Hany, Eteiba, Mitchell, Lindsay, Stuart, Hood, Stuart, Watkins, Andrew, Davie, Ahmed, Mahrous, Ify, Mordi, Nadeem, Ahmed, Vannesa, Teng Yue May, Ian, Ford, Aleksandra, Radjenovic, Paul, Welsh, Naveed, Sattar, Keith G, Oldroyd, and Colin, Berry
- Subjects
Adult ,Heart Failure ,Male ,Edema, Cardiac ,Smokers ,Time Factors ,Ventricular Remodeling ,Microcirculation ,Myocardium ,Smoking ,Myocardial Reperfusion Injury ,Middle Aged ,Magnetic Resonance Imaging ,Risk Assessment ,Percutaneous Coronary Intervention ,Treatment Outcome ,Predictive Value of Tests ,Risk Factors ,Coronary Circulation ,Humans ,ST Elevation Myocardial Infarction ,Female ,Prospective Studies ,Aged - Abstract
The aim of this study was to mechanistically investigate associations among cigarette smoking, microvascular pathology, and longer term health outcomes in patients with acute ST-segment elevation myocardial infarction (MI).The pathophysiology of myocardial reperfusion injury and prognosis in smokers with acute ST-segment elevation MI is incompletely understood.Patients were prospectively enrolled during emergency percutaneous coronary intervention. Microvascular function in the culprit artery was measured invasively. Contrast-enhanced magnetic resonance imaging (1.5-T) was performed 2 days and 6 months post-MI. Infarct size and microvascular obstruction were assessed using late gadolinium enhancement imaging. Myocardial hemorrhage was assessed with T2* mapping. Pre-specified endpoints included: 1) all-cause death or first heart failure hospitalization; and 2) cardiac death, nonfatal MI, or urgent coronary revascularization (major adverse cardiovascular events). Binary logistic regression (odds ratio [OR] with 95% confidence interval [CI]) with smoking status was used.In total, 324 patients with ST-segment elevation MI were enrolled (mean age 59 years, 73% men, 60% current smokers). Current smokers were younger (age 55 ± 11 years vs. 65 ± 10 years, p 0.001), with fewer patients with hypertension (52 ± 27% vs. 53 ± 41%, p = 0.007). Smokers had better TIMI (Thrombolysis In Myocardial Infarction) flow grade (≥2 vs. ≤1, p = 0.024) and ST-segment resolution (none vs. partial vs. complete, p = 0.010) post-percutaneous coronary intervention. On day 1, smokers had higher circulating C-reactive protein, neutrophil, and monocyte levels. Two days post-MI, smoking independently predicted infarct zone hemorrhage (OR: 2.76; 95% CI: 1.42 to 5.37; p = 0.003). After a median follow-up period of 4 years, smoking independently predicted all-cause death or heart failure events (OR: 2.20; 95% CI: 1.07 to 4.54) and major adverse cardiovascular events (OR: 2.79; 95% CI: 2.30 to 5.99).Smoking is associated with enhanced inflammation acutely, infarct-zone hemorrhage subsequently, and longer term adverse cardiac outcomes. Inflammation and irreversible myocardial hemorrhage post-MI represent mechanistic drivers for adverse long-term prognosis in smokers. (Detection and Significance of Heart Injury in ST Elevation Myocardial Infarction. [BHF MR-MI]; NCT02072850).
- Published
- 2018
34. Ferumoxytol-enhanced magnetic resonance angiography for the assessment of potential kidney transplant recipients
- Author
-
Aleksandra Radjenovic, Ram Kasthuri, Martin Hennessy, Alex T. Vesey, Sokratis Stoumpos, Patrick B. Mark, David B. Kingsmore, and Giles Roditi
- Subjects
Male ,medicine.medical_specialty ,Contrast Media ,030204 cardiovascular system & hematology ,Kidney ,Magnetic resonance angiography ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Magnetic resonance imaging ,0302 clinical medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Magnetic Resonance ,Kidney transplantation ,Neuroradiology ,medicine.diagnostic_test ,business.industry ,Vascular disease ,Patient Selection ,Angiography ,General Medicine ,Middle Aged ,Image Enhancement ,medicine.disease ,Kidney Transplantation ,Ferrosoferric Oxide ,Ferumoxytol ,Female ,Radiology ,Kidney failure, chronic ,business ,Ferric compounds ,Magnetic Resonance Angiography ,Kidney disease - Abstract
Traditional contrast-enhanced methods for scanning blood vessels using magnetic resonance imaging (MRI) or CT carry potential risks for patients with advanced kidney disease. Ferumoxytol is a superparamagnetic iron oxide nanoparticle preparation that has potential as an MRI contrast agent in assessing the vasculature. Twenty patients with advanced kidney disease requiring aorto-iliac vascular imaging as part of pre-operative kidney transplant candidacy assessment underwent ferumoxytol-enhanced magnetic resonance angiography (FeMRA) between December 2015 and August 2016. All scans were performed for clinical indications where standard imaging techniques were deemed potentially harmful or inconclusive. Image quality was evaluated for both arterial and venous compartments. First-pass and steady-state FeMRA using incremental doses of up to 4 mg/kg body weight of ferumoxytol as intravenous contrast agent for vascular enhancement was performed. Good arterial and venous enhancements were achieved, and FeMRA was not limited by calcification in assessing the arterial lumen. The scans were diagnostic and all patients completed their studies without adverse events. Our preliminary experience supports the feasibility and utility of FeMRA for vascular imaging in patients with advanced kidney disease due for transplant listing, which has the advantages of obtaining both arteriography and venography using a single test without nephrotoxicity. • Evaluation of vascular disease is important in planning kidney transplantation. • Standard vascular imaging methods are often problematic in kidney disease patients. • FeMRA has the advantage of arteriography and venography in a single test. • FeMRA is safe and non-nephrotoxic. • FeMRA is not limited by arterial calcification.
- Published
- 2018
35. Comparison of the Diagnostic Performance of Four Quantitative Myocardial Perfusion Estimation Methods Used in Cardiac MR Imaging: CE-MARC Substudy
- Author
-
John D Biglands, Derek R. Magee, John P Greenwood, Aleksandra Radjenovic, Sven Plein, and Steven Sourbron
- Subjects
Adult ,Male ,medicine.medical_specialty ,Coronary Disease ,Perfusion scanning ,Myocardial perfusion imaging ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Original Research ,Aged ,Retrospective Studies ,medicine.diagnostic_test ,business.industry ,Myocardial Perfusion Imaging ,Magnetic resonance imaging ,Blood flow ,Middle Aged ,Magnetic Resonance Imaging ,Mr imaging ,Cardiac Imaging Techniques ,Cardiology ,Female ,Estimation methods ,business ,Perfusion - Abstract
To compare the diagnostic performance of four tracer kinetic analysis methods to quantify myocardial perfusion from magnetic resonance (MR) imaging cardiac perfusion data sets in terms of their ability to lead to the diagnosis of myocardial ischemia.The study was approved by the regional ethics committee, and all patients gave written consent. A representative sample of 50 patients with suspected ischemic heart disease was retrospectively selected from the Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease trial data set. Quantitative myocardial blood flow (MBF) was estimated from rest and adenosine stress MR imaging perfusion data sets by using four established methods. A matching diagnosis of both an inducible defect as assessed with single photon emission computed tomography and a luminal stenosis of 70% or more as assessed with quantitative x-ray angiography was used as the reference standard for the presence of myocardial ischemia. Diagnostic performance was evaluated with receiver operating characteristic (ROC) curve analysis for each method, with stress MBF and myocardial perfusion reserve (MPR) serving as continuous measures.Area under the ROC curve with stress MBF and MPR as the outcome measures, respectively, was 0.86 and 0.92 for the Fermi model, 0.85 and 0.87 for the uptake model, 0.85 and 0.80 for the one-compartment model, and 0.87 and 0.87 for model-independent deconvolution. There was no significant difference between any of the models or between MBF and MPR, except that the Fermi model outperformed the one-compartment model if MPR was used as the outcome measure (P = .02).Diagnostic performance of quantitative myocardial perfusion estimates is not affected by the tracer kinetic analysis method used.
- Published
- 2015
36. P2471A randomised, placebo-controlled trial of the effects of IV serelaxin on myocardial blood flow and vascular function in patients with stable coronary artery disease (CAD)
- Author
-
Aleksandra Radjenovic, M.E. Hinder, Sheraz A Nazir, B. Gugliotta, David Corcoran, Gerry P McCann, David E. Newby, Colin Berry, Scott Semple, Denise Yates, Ify R. Mordi, Iain B. Squire, Niko Tzemos, S. Machineni, and S. Wilson
- Subjects
medicine.medical_specialty ,business.industry ,Placebo-controlled study ,CAD ,Blood flow ,medicine.disease ,Coronary artery disease ,Serelaxin ,Internal medicine ,Cardiology ,Medicine ,In patient ,Cardiology and Cardiovascular Medicine ,business ,Vascular function - Published
- 2017
37. Quantitative Myocardial Perfusion Imaging Versus Visual Analysis in Diagnosing Myocardial Ischemia: A CE-MARC Substudy
- Author
-
John D, Biglands, Montasir, Ibraheem, Derek R, Magee, Aleksandra, Radjenovic, Sven, Plein, and John P, Greenwood
- Subjects
Male ,Myocardial Ischemia ,Myocardial Perfusion Imaging ,Reproducibility of Results ,Middle Aged ,Coronary Angiography ,Magnetic Resonance Imaging ,Predictive Value of Tests ,Coronary Circulation ,Image Interpretation, Computer-Assisted ,Humans ,Female ,Aged ,Retrospective Studies - Abstract
This study sought to compare the diagnostic accuracy of visual and quantitative analyses of myocardial perfusion cardiovascular magnetic resonance against a reference standard of quantitative coronary angiography.Visual analysis of perfusion cardiovascular magnetic resonance studies for assessing myocardial perfusion has been shown to have high diagnostic accuracy for coronary artery disease. However, only a few small studies have assessed the diagnostic accuracy of quantitative myocardial perfusion.This retrospective study included 128 patients randomly selected from the CE-MARC (Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease) study population such that the distribution of risk factors and disease status was proportionate to the full population. Visual analysis results of cardiovascular magnetic resonance perfusion images, by consensus of 2 expert readers, were taken from the original study reports. Quantitative myocardial blood flow estimates were obtained using Fermi-constrained deconvolution. The reference standard for myocardial ischemia was a quantitative coronary x-ray angiogram stenosis severity of ≥70% diameter in any coronary artery of2 mm diameter, or ≥50% in the left main stem. Diagnostic performance was calculated using receiver-operating characteristic curve analysis.The area under the curve for visual analysis was 0.88 (95% confidence interval: 0.81 to 0.95) with a sensitivity of 81.0% (95% confidence interval: 69.1% to 92.8%) and specificity of 86.0% (95% confidence interval: 78.7% to 93.4%). For quantitative stress myocardial blood flow the area under the curve was 0.89 (95% confidence interval: 0.83 to 0.96) with a sensitivity of 87.5% (95% confidence interval: 77.3% to 97.7%) and specificity of 84.5% (95% confidence interval: 76.8% to 92.3%). There was no statistically significant difference between the diagnostic performance of quantitative and visual analyses (p = 0.72). Incorporating rest myocardial blood flow values to generate a myocardial perfusion reserve did not significantly increase the quantitative analysis area under the curve (p = 0.79).Quantitative perfusion has a high diagnostic accuracy for detecting coronary artery disease but is not superior to visual analysis. The incorporation of rest perfusion imaging does not improve diagnostic accuracy in quantitative perfusion analysis.
- Published
- 2017
38. Cardiac MR Imaging to Measure Myocardial Blood Flow Response to the Cold Pressor Test in Healthy Smokers and Nonsmokers
- Author
-
Aleksandra Radjenovic, Sven Plein, Adam N Mather, Manish Motwani, John D Biglands, John P Greenwood, Abdulghani M Larghat, and Timothy A. Fairbairn
- Subjects
Gadolinium DTPA ,Male ,medicine.medical_specialty ,Adenosine ,Measure (physics) ,Contrast Media ,Young Adult ,Coronary Circulation ,Internal medicine ,Image Interpretation, Computer-Assisted ,Healthy volunteers ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,business.industry ,Smoking ,Hemodynamics ,Myocardial Perfusion Imaging ,Cold pressor test ,Blood flow ,Magnetic Resonance Imaging ,Mr imaging ,Healthy Volunteers ,Exercise Test ,Cardiology ,Female ,Endothelium, Vascular ,business ,Perfusion ,Blood Flow Velocity - Abstract
To determine if myocardial perfusion cardiac magnetic resonance (MR) imaging can show changes in myocardial blood flow (MBF) during the cold pressor test (CPT) and can allow identification of the differing endothelial function of smokers and nonsmokers when compared during adenosine stress.The study was approved by the institutional ethics review board and all participants gave informed written consent. Twenty-nine healthy volunteers (19 nonsmokers, 10 smokers; mean age ± standard deviation, 22 years ± 4) underwent 1.5-T MR imaging and analysis. Myocardial perfusion was assessed during rest, peak CPT, and adenosine hyperemia with a saturation-recovery gradient-echo pulse sequence (spatial resolution, 2.4 × 2.4 × 10 mm). Global, endocardial, and epicardial MBF were calculated by using Fermi-constrained deconvolution. Paired and independent t test statistical analyses were used to compare the responses between tests and groups. Regression analysis was performed to identify predictors of MBF change.MBF at rest was similar between the nonsmoking and smoking groups (0.97 mL/g/min ± 0.4 vs 0.96 mL/g/min ± 0.3, respectively; P = .96). Nonsmokers responded to CPT with a 47% increase in MBF (1.43 mL/g/min ± 0.5) and smokers responded with a 27% increase (1.22 mL/g/min ± 0.4; P.001). An endocardial-to-epicardial gradient existed at rest (nonsmokers, 1.10 [P = .002]; smokers, 1.30 [P = .01]) and CPT (nonsmokers, 1.19 [P.001] smokers, 1.28 [P = .04]) but reversed during adenosine stress (nonsmokers, 0.89 [P = .03]; smokers, 0.92 [P = .42]).Myocardial perfusion cardiac MR imaging during CPT can allow assessment of changes in MBF globally and in the separate myocardial layers in healthy smokers and nonsmokers. This allows the combined assessment of endothelium-dependent (CPT) and endothelium-independent (adenosine stress test) MBF reserve in a single study.
- Published
- 2014
39. LEO 6. Ferumoxytol-Enhanced Magnetic Resonance Angiography—Clinical Feasibility and Optimal Dosing
- Author
-
Aleksandra Radjenovic, Martin Hennessy, Sokratis Stoumpos, Patrick B. Mark, Alex T. Vesey, David B. Kingsmore, and Giles Roditi
- Subjects
Ferumoxytol ,medicine.diagnostic_test ,business.industry ,medicine ,Surgery ,Dosing ,Cardiology and Cardiovascular Medicine ,Nuclear medicine ,business ,Magnetic resonance angiography - Published
- 2018
40. Reproducibility of first-pass cardiovascular magnetic resonance myocardial perfusion
- Author
-
Michael Jerosch-Herold, Neil Maredia, Stephen G. Ball, John D Biglands, Aleksandra Radjenovic, Abdulghani M Larghat, Sven Plein, and John P Greenwood
- Subjects
Adult ,Male ,Coefficient of variation ,Diastole ,Ventricular Function, Left ,Reference Values ,Ventriculography, First-Pass ,Coronary Circulation ,Image Interpretation, Computer-Assisted ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Observer Variation ,First pass ,Reproducibility ,medicine.diagnostic_test ,business.industry ,Myocardial Perfusion Imaging ,Reproducibility of Results ,Magnetic resonance imaging ,Blood flow ,Image Enhancement ,Female ,Nuclear medicine ,business ,Perfusion ,Quantitative analysis (chemistry) ,Magnetic Resonance Angiography - Abstract
Purpose: To assess the reproducibility of semiquantitative and quantitative analysis of first-pass myocardial perfusion cardiovascular magnetic resonance (CMR) in healthy volunteers. Materials and Methods: Eleven volunteers underwent myocardial perfusion CMR during adenosine stress and rest on 2 separate days. Perfusion data were acquired in a single mid-ventricular section in two cardiac phases to permit cardiac phase reproducibility comparisons. Semiquantitative analysis was performed to derive normalized upslopes of myocardial signal intensity profiles (myocardial perfusion index, MPI). The quantitative analysis estimated absolute myocardial blood flow (MBF) using Fermi-constrained deconvolution. The perfusion reserve index was calculated by dividing stress by rest data. Two observers performed all the measurements independently. One observer repeated all first scan measurements 4 weeks later. Results: The reproducibility of perfusion CMR was highest for semiquantitative analysis with an intraobserver coefficient of variability (CoV) of 3%–7% and interobserver CoV of 4%–10%. Semiquantitative interstudy comparison was less reproducible (CoV of 13%–27%). Quantitative intraobserver CoV of 10%–18%, interobserver CoV of 8%–15% and interstudy CoV of 20%–41%. Reproducibility of systolic and diastolic phases and the endocardial and epicardial myocardial layer showed similar reproducibility on both semiquantitative and quantitative analysis. Conclusion: The reproducibility of CMR myocardial perfusion estimates is good, but varies between intraobserver, interobserver, and interstudy comparisons. In this study semiquantitative analysis was more reproducible than quantitative analysis. J. Magn. Reson. Imaging 2013;37:865–874. © 2013 Wiley Periodicals, Inc.
- Published
- 2013
41. Investigation into diagnostic accuracy of common strategies for automated perfusion motion correction
- Author
-
Aleksandra Radjenovic, Roger D. Boyle, Constantine Zakkaroff, Sven Plein, John P Greenwood, Derek R. Magee, and John D Biglands
- Subjects
Motion analysis ,medicine.diagnostic_test ,Transform theory ,business.industry ,Image Processing ,Image registration ,030204 cardiovascular system & hematology ,Single-photon emission computed tomography ,Translation (geometry) ,Motion (physics) ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Medical imaging ,Radiology, Nuclear Medicine and imaging ,Computer vision ,Artificial intelligence ,business ,Nuclear medicine ,Rotation (mathematics) - Abstract
Respiratory motion is a significant obstacle to the use of quantitative perfusion in clinical practice. Increasingly complex motion correction algorithms are being developed to correct for respiratory motion. However, the impact of these improvements on the final diagnosis of ischemic heart disease has not been evaluated. The aim of this study was to compare the performance of four automated correction methods in terms of their impact on diagnostic accuracy. Three strategies for motion correction were used: (1) independent translation correction for all slices, (2) translation correction for the basal slice with transform propagation to the remaining two slices assuming identical motion in the remaining slices, and (3) rigid correction (translation and rotation) for the basal slice. There were no significant differences in diagnostic accuracy between the manual and automatic motion-corrected datasets ([Formula: see text]). The area under the curve values for manual motion correction and automatic motion correction were 0.93 and 0.92, respectively. All of the automated motion correction methods achieved a comparable diagnostic accuracy to manual correction. This suggests that the simplest automated motion correction method (method 2 with translation transform for basal location and transform propagation to the remaining slices) is a sufficiently complex motion correction method for use in quantitative myocardial perfusion.
- Published
- 2016
42. The cardiac toxicity CMR Study in patients with lung cancer treated with chemo-radiotherapy: The CART study- a semi quantitative analysis of the myocardial perfusion index
- Author
-
Nazia Mohammed, Aleksandra Radjenovic, S. Nowicki, Naveed Sattar, Jon Stobo, M. Glegg, Marimuthu Sankaralingham, Claire Lawless, Kenneth Mangion, Colin Berry, James Paul, John Foster, and Noelle O'Rourke
- Subjects
Medicine(all) ,Cart ,Chemo-radiotherapy ,medicine.medical_specialty ,Radiological and Ultrasound Technology ,business.industry ,Perfusion index ,medicine.disease ,Text mining ,Cardiac toxicity ,Poster Presentation ,Medicine ,Radiology, Nuclear Medicine and imaging ,Radiology ,Cardiology and Cardiovascular Medicine ,business ,Lung cancer ,Semi quantitative ,Angiology - Published
- 2016
43. Right Ventricular free wall myocardial tissue characterisation by systolic Cardiac Magnetic Resonance T1 mapping in pulmonary hypertension
- Author
-
Andrew J. Peacock, Colin Church, Geeshath Jayasekera, Martin Johnson, and Aleksandra Radjenovic
- Subjects
Medicine(all) ,medicine.medical_specialty ,Radiological and Ultrasound Technology ,Myocardial tissue ,business.industry ,medicine.disease ,Pulmonary hypertension ,Right ventricular dysfunction ,Right ventricular ejection fraction ,Internal medicine ,Poster Presentation ,medicine ,Cardiology ,Radiology, Nuclear Medicine and imaging ,Radiology ,Right Ventricular Free Wall ,Cardiology and Cardiovascular Medicine ,business ,Cardiac magnetic resonance ,Angiology - Published
- 2016
44. Myocardial haemorrhage after acute reperfused ST-elevation myocardial infarction evolves progressively and contributes to the early bimodal pattern in T2-relaxation time: advanced imaging and clinical significance
- Author
-
David Carrick, Keith G. Oldroyd, Jaclyn Carberry, Margaret McEntegart, Nadeem Ahmed, Samuli M Rauhalammi, Ian Ford, Ahmed Mahrous, Mitchell Lindsay, Ify R. Mordi, Naveed Sattar, Stuart Watkins, Paul Welsh, Hany Eteiba, Guillaume Clerfond, Stuart Hood, Caroline Haig, Mark C. Petrie, Colin Berry, and Aleksandra Radjenovic
- Subjects
Medicine(all) ,medicine.medical_specialty ,Radiological and Ultrasound Technology ,business.industry ,Text mining ,St elevation myocardial infarction ,Internal medicine ,T2 relaxation ,Poster Presentation ,medicine ,Cardiology ,Radiology, Nuclear Medicine and imaging ,Clinical significance ,Radiology ,Cardiology and Cardiovascular Medicine ,business ,Angiology - Published
- 2016
45. Remote Zone Extracellular Volume and Left Ventricular Remodeling in Survivors of ST-Elevation Myocardial Infarction
- Author
-
Jaclyn Carberry, Colin Berry, Samuli M Rauhalammi, Ian Ford, Ify Mordi, Paul Welsh, Naveed Sattar, Ahmed Mahrous, Andrew Davie, Hany Eteiba, Mitchell Lindsay, David Carrick, Nadeem Ahmed, Stuart Hood, Margaret McEntegart, Keith G. Oldroyd, Stuart Watkins, Caroline Haig, Mark C. Petrie, and Aleksandra Radjenovic
- Subjects
Male ,medicine.medical_specialty ,extracellular matrix ,Statistics as Topic ,Magnetic Resonance Imaging, Cine ,030204 cardiovascular system & hematology ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Random Allocation ,0302 clinical medicine ,Cardiac magnetic resonance imaging ,Diabetes mellitus ,Internal medicine ,Internal Medicine ,Medicine ,Humans ,magnetic resonance imaging ,Myocardial infarction ,Ventricular remodeling ,Aged ,Ejection fraction ,medicine.diagnostic_test ,Ventricular Remodeling ,business.industry ,Myocardium ,Magnetic resonance imaging ,Stroke Volume ,Heart ,Stroke volume ,Original Articles ,Middle Aged ,medicine.disease ,Confidence interval ,myocardial infarction ,Cardiology ,ComputingMethodologies_DOCUMENTANDTEXTPROCESSING ,ST Elevation Myocardial Infarction ,Female ,business ,Extracellular Space ,edema - Abstract
Supplemental Digital Content is available in the text., The natural history and pathophysiological significance of tissue remodeling in the myocardial remote zone after acute ST-elevation myocardial infarction (STEMI) is incompletely understood. Extracellular volume (ECV) in myocardial regions of interest can now be measured with cardiac magnetic resonance imaging. Patients who sustained an acute STEMI were enrolled in a cohort study (BHF MR-MI [British Heart Foundation Magnetic Resonance Imaging in Acute ST-Segment Elevation Myocardial Infarction study]). Cardiac magnetic resonance was performed at 1.5 Tesla at 2 days and 6 months post STEMI. T1 modified Look-Locker inversion recovery mapping was performed before and 15 minutes after contrast (0.15 mmol/kg gadoterate meglumine) in 140 patients at 2 days post STEMI (mean age: 59 years, 76% male) and in 131 patients at 6 months post STEMI. Remote zone ECV was lower than infarct zone ECV (25.6±2.8% versus 51.4±8.9%; P
- Published
- 2016
46. Myocardial strain in healthy adults across a broad age range as revealed by cardiac magnetic resonance imaging at 1.5 and 3.0T: Associations of myocardial strain with myocardial region, age, and sex
- Author
-
Kenneth, Mangion, Guillaume, Clerfond, Christie, McComb, David, Carrick, Samuli M, Rauhalammi, John, McClure, David S, Corcoran, Rosemary, Woodward, Vanessa, Orchard, Aleksandra, Radjenovic, Xiaodong, Zhong, and Colin, Berry
- Subjects
Adult ,Male ,Aging ,Adolescent ,Compressive Strength ,Heart Ventricles ,Middle Aged ,Magnetic Resonance Imaging ,Ventricular Function, Left ,Young Adult ,Sex Factors ,healthy volunteers ,Reference Values ,Elastic Modulus ,Tensile Strength ,myocardial strain ,Anisotropy ,Elasticity Imaging Techniques ,Humans ,Female ,Stress, Mechanical ,displacement encoding with stimulated echoes ,Cardiac ,Aged ,Original Research - Abstract
Purpose To assess myocardial strain using cine displacement encoding with stimulated echoes (DENSE) using 1.5T and 3.0T MRI in healthy adults. Materials and Methods Healthy adults without any history of cardiovascular disease underwent magnetic resonance imaging (MRI) at 1.5T and 3.0T within 2 days. The MRI protocol included balanced steady‐state free‐precession (b‐SSFP), 2D cine‐echo planar imaging (EPI)‐DENSE, and late gadolinium enhancement in subjects >45 years. Acquisitions were divided into six segments; global and segmental peak longitudinal and circumferential strain were derived and analyzed by field strength, age, and gender. Results In all, 89 volunteers (mean age 44.8 ± 18.0 years, range: 18–87 years) underwent MRI at 1.5T, and 88 of these subjects underwent MRI at 3.0T (1.4 ± 1.4 days between the scans). Compared with 3.0T, the magnitudes of global circumferential (–19.5 ± 2.6% vs. –18.47 ± 2.6%; P = 0.001) and longitudinal (–12.47 ± 3.2% vs. –10.53 ± 3.1%; P = 0.004) strain were greater at 1.5T. At 1.5T, longitudinal strain was greater in females than in males: –10.17 ± 3.4% vs. –13.67 ± 2.4%; P = 0.001. Similar observations occurred for circumferential strain at 1.5T (–18.72 ± 2.2% vs. –20.10 ± 2.7%; P = 0.014) and at 3.0T (–17.92 ± 1.8% vs. –19.1 ± 3.1%; P = 0.047). At 1.5T, longitudinal and circumferential strain were not associated with age after accounting for sex (longitudinal strain P = 0.178, circumferential strain P = 0.733). At 3.0T, longitudinal and circumferential strain were associated with age (P < 0.05). Longitudinal strain values were greater in the apico‐septal, basal‐lateral, and mid‐lateral segments and circumferential strain in the inferior, infero‐lateral, and antero‐lateral LV segments. Conclusion Myocardial strain parameters as revealed by cine‐DENSE at different MRI field strengths were associated with myocardial region, age, and sex. J. Magn. Reson. Imaging 2016;44:1197–1205.
- Published
- 2016
47. Non-Contrast Renal Magnetic Resonance Imaging to Assess Perfusion and Corticomedullary Differentiation in Health and Chronic Kidney Disease
- Author
-
Christian Delles, Markus P. Schneider, Keith Gillis, Kathryn K. Stevens, Aleksandra Radjenovic, Scott T W Morris, Giles Roditi, Patrick B. Mark, Rajan K. Patel, and Christie McComb
- Subjects
Adult ,Male ,medicine.medical_specialty ,Kidney Cortex ,030232 urology & nephrology ,Renal function ,Perfusion scanning ,urologic and male genital diseases ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Medizinische Fakultät ,Internal medicine ,medicine ,otorhinolaryngologic diseases ,Humans ,Pathological ,Aged ,ddc:616 ,Kidney ,Kidney Medulla ,medicine.diagnostic_test ,business.industry ,Case-control study ,Magnetic resonance imaging ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Case-Control Studies ,Cardiology ,Kidney Failure, Chronic ,Female ,Radiology ,business ,Perfusion ,Kidney disease - Abstract
Aims: Arterial spin labelling (ASL) MRI measures perfusion without administration of contrast agent. While ASL has been validated in animals and healthy volunteers (HVs), application to chronic kidney disease (CKD) has been limited. We investigated the utility of ASL MRI in patients with CKD. Methods: We studied renal perfusion in 24 HVs and 17 patients with CKD (age 22-77 years, 40% male) using ASL MRI at 3.0T. Kidney function was determined using estimated glomerular filtration rate (eGFR). T1 relaxation time was measured using modified look-locker inversion and flow-sensitive alternating inversion recovery true-fast imaging and steady precession was performed to measure cortical and whole kidney perfusion. Results: T1 was higher in CKD within cortex and whole kidney, and there was association between T1 time and eGFR. No association was seen between kidney size and volume and either T1, or ASL perfusion. Perfusion was lower in CKD in cortex (136 ± 37 vs. 279 ± 69 ml/min/100 g; p < 0.001) and whole kidney (146 ± 24 vs. 221 ± 38 ml/min/100 g; p < 0.001). There was significant, negative, association between T1 longitudinal relaxation time and ASL perfusion in both the cortex (r = -0.75, p < 0.001) and whole kidney (r = -0.50, p < 0.001). There was correlation between eGFR and both cortical (r = 0.73, p < 0.01) and whole kidney (r = 0.69, p < 0.01) perfusion. Conclusions: Significant differences in renal structure and function were demonstrated using ASL MRI. T1 may be representative of structural changes associated with CKD; however, further investigation is required into the pathological correlates of reduced ASL perfusion and increased T1 time in CKD.
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- 2016
48. Pixel-tracking derived strain using the GlasgowHeart Method
- Author
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Kenneth Mangion, Colin Berry, Xiaoyu Luo, Hao Gao, Caroline Haig, and Aleksandra Radjenovic
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Medicine(all) ,Subset Analysis ,medicine.medical_specialty ,Contouring ,Radiological and Ultrasound Technology ,Pixel ,Observer (quantum physics) ,Strain (chemistry) ,business.industry ,Pearson product-moment correlation coefficient ,Surgery ,symbols.namesake ,Poster Presentation ,medicine ,symbols ,Circumferential strain ,Radiology, Nuclear Medicine and imaging ,Cardiology and Cardiovascular Medicine ,business ,Nuclear medicine ,Angiology - Abstract
Background:\ud \ud Estimation of strain parameters from cine acquisitions, such as balanced steady state free precession (b-SSFP) is advantageous, as it would obviate the need for acquisition of additional strain sequences reducing scanning time and making strain more accessible to clinicians. 2D strain derived from feature-tracking is now commercially available. The GlasgowHeart cine-strain method is designed to overcome some limitations of currently available feature-tracking methods by estimating pixel-wise strain for myocardial deformation incorporating all of the myocardial tissues. The aims of this pilot study was to ensure that 2D peak circumferential strain estimated from the GlasgowHeart method is feasible in healthy volunteers (n = 20) and reproducible with minimal intra- and inter- observer variability.\ud \ud Methods:\ud \ud Healthy volunteers aged at least 18 years of age with no prior medical history were invited to participate. A subset of 20 healthy adult volunteers underwent 1.5T CMR twice, < 2 days apart. Written consent was obtained. Mid-LV cine sequences, were analysed with the GlasgowHeart software. The process involves contouring the myocardial borders at end-diastole and segmenting the myocardium by using the right ventricular insertion point according to the 16 segment AHA model. Two observers independently analysed 40 short axis slices using the cine-strain method for inter-observer variability. One observer re-analysed the 40 short axis slices 10 days later for intra-observer variability. Scans were analysed in a random order. Pearson correlation and Bland-Altman analysis were used to analyse the data.\ud \ud Results:\ud \ud 20 participants were used in the subset analysis (mean age ± SD 49.5 years (17.2) 50% male). Peak circumferential strain (Ecc) measured on the first set of MRIs by the two observers (Figure 2A,B) was highly correlated (R = 0.915, p < 0.001) and in excellent agreement (mean difference = 0.01; 95% LoA: -0.01, 0.02). The repeated image analysis (Figure 2C,D) also disclosed a high degree of association in paired measurements of Ecc that was strongly correlated(R= 0.915, p< 0.001) and in excellent agreement (mean difference = 0.00; 95% LoA: -0.02, 0.01). Ecc measured in the second set of MRIs by 2 observers was well correlated (R = 0.937, p < 0.001) and in excellent agreement (mean difference = 0.00; 95% limits of agreement were -0.016 and 0.021). The repeated image analysis at follow-up yielded Ecc that was well correlated(R= 0.942, p < 0.001) and in excellent agreement (mean = 0.00; 95% LoA: -0.009 and 0.009). There was no difference between the average global Ecc at different time points (p > 0.05).
- Published
- 2016
49. Myocardial Hemorrhage After Acute Reperfused ST-Segment–Elevation Myocardial Infarction
- Author
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David, Carrick, Caroline, Haig, Nadeem, Ahmed, Margaret, McEntegart, Mark C, Petrie, Hany, Eteiba, Stuart, Hood, Stuart, Watkins, M Mitchell, Lindsay, Andrew, Davie, Ahmed, Mahrous, Ify, Mordi, Samuli, Rauhalammi, Naveed, Sattar, Paul, Welsh, Aleksandra, Radjenovic, Ian, Ford, Keith G, Oldroyd, and Colin, Berry
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Male ,Microcirculation ,Myocardial Infarction ,myocardial reperfusion ,Contrast Media ,Hemorrhage ,Original Articles ,Middle Aged ,Coronary Angiography ,Electrocardiography ,ComputingMethodologies_DOCUMENTANDTEXTPROCESSING ,magnetic resonance imaging ,Humans ,Female ,Prospective Studies ,prognosis ,Biomarkers ,Magnetic Resonance Angiography - Abstract
Supplemental Digital Content is available in the text., Background— The success of coronary reperfusion therapy in ST-segment–elevation myocardial infarction (MI) is commonly limited by failure to restore microvascular perfusion. Methods and Results— We performed a prospective cohort study in patients with reperfused ST-segment–elevation MI who underwent cardiac magnetic resonance 2 days (n=286) and 6 months (n=228) post MI. A serial imaging time-course study was also performed (n=30 participants; 4 cardiac magnetic resonance scans): 4 to 12 hours, 2 days, 10 days, and 7 months post reperfusion. Myocardial hemorrhage was taken to represent a hypointense infarct core with a T2* value of
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- 2016
50. High-Resolution Versus Standard-Resolution Cardiovascular MR Myocardial Perfusion Imaging for the Detection of Coronary Artery Disease
- Author
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Neil Maredia, Sebastian Kozerke, Manish Motwani, Aleksandra Radjenovic, Sven Plein, John P Greenwood, Timothy A. Fairbairn, University of Zurich, and Plein, S
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Male ,medicine.medical_specialty ,High resolution ,610 Medicine & health ,Coronary Artery Disease ,030204 cardiovascular system & hematology ,2705 Cardiology and Cardiovascular Medicine ,030218 nuclear medicine & medical imaging ,170 Ethics ,Coronary artery disease ,03 medical and health sciences ,Myocardial perfusion imaging ,0302 clinical medicine ,Internal medicine ,Image Processing, Computer-Assisted ,medicine ,Humans ,2741 Radiology, Nuclear Medicine and Imaging ,10237 Institute of Biomedical Engineering ,Radiology, Nuclear Medicine and imaging ,In patient ,Subendocardial ischemia ,Observer Variation ,medicine.diagnostic_test ,business.industry ,Myocardial Perfusion Imaging ,Area under the curve ,Reproducibility of Results ,Middle Aged ,medicine.disease ,Stenosis ,ROC Curve ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business ,Perfusion ,Magnetic Resonance Angiography - Abstract
Background— Although accelerated high-spatial-resolution cardiovascular MR (CMR) myocardial perfusion imaging has been shown to be clinically feasible, there has not yet been a direct comparison with standard-resolution methods. We hypothesized that higher spatial resolution detects more subendocardial ischemia and leads to greater diagnostic accuracy for the detection coronary artery disease. This study compared the diagnostic accuracy of high-resolution and standard-resolution CMR myocardial perfusion imaging in patients with suspected coronary artery disease. Methods and Results— A total of 111 patients were recruited to undergo 2 separate perfusion-CMR studies at 1.5 T, 1 with standard-resolution (2.5×2.5 mm in-plane) and 1 with high-resolution (1.6×1.6 mm in-plane) acquisition. High-resolution acquisition was facilitated by 8-fold k-t broad linear speed-up technique acceleration. Two observers visually graded perfusion in each myocardial segment on a 4-point scale. Segmental scores were summed to produce a perfusion score for each patient. All patients underwent invasive coronary angiography and coronary artery disease was defined as stenosis ≥50% luminal diameter (quantitative coronary angiography). CMR data were successfully obtained in 100 patients. In patients with coronary artery disease (n=70), more segments were determined to have subendocardial ischemia with high-resolution than with standard-resolution acquisition (279 versus 108; P P P =0.002) and overall (area under the curve, 0.93 versus 0.83; P Conclusions— High-resolution perfusion-CMR has greater overall diagnostic accuracy than standard-resolution acquisition for the detection of coronary artery disease in both single- and multivessel disease and detects more subendocardial ischemia.
- Published
- 2012
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