181 results on '"Aleksandra Radjenovic"'
Search Results
52. 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
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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
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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
53. Right Ventricular free wall myocardial tissue characterisation by systolic Cardiac Magnetic Resonance T1 mapping in pulmonary hypertension
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Andrew J. Peacock, Colin Church, Geeshath Jayasekera, Martin Johnson, and Aleksandra Radjenovic
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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
54. 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
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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
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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
55. Remote Zone Extracellular Volume and Left Ventricular Remodeling in Survivors of ST-Elevation Myocardial Infarction
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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
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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
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- 2016
56. 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
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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
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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.
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- 2016
57. Non-Contrast Renal Magnetic Resonance Imaging to Assess Perfusion and Corticomedullary Differentiation in Health and Chronic Kidney Disease
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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
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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
58. Pixel-tracking derived strain using the GlasgowHeart Method
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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).
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- 2016
59. Myocardial Hemorrhage After Acute Reperfused ST-Segment–Elevation Myocardial Infarction
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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
60. High-Resolution Versus Standard-Resolution Cardiovascular MR Myocardial Perfusion Imaging for the Detection of Coronary Artery Disease
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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.
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- 2012
61. Spin–lattice relaxation rates and water content of freeze-dried articular cartilage
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Eileen Ingham, Sainath Shrikant Pawaskar, Michael E. Ries, Samantha P. Williams, Zhongmin Jin, Robin A. Damion, and Aleksandra Radjenovic
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Cartilage, Articular ,Magnetic Resonance Spectroscopy ,Sus scrofa ,Body water ,Biomedical Engineering ,Spin–lattice relaxation ,Articular cartilage ,Models, Biological ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Freeze-drying ,0302 clinical medicine ,Nuclear magnetic resonance ,Body Water ,Species Specificity ,Rheumatology ,medicine ,Animals ,Orthopedics and Sports Medicine ,Water content ,Chemistry ,Cartilage ,Relaxation (NMR) ,Anatomy ,Longitudinal relaxation ,Freeze Drying ,medicine.anatomical_structure ,Relaxation rate ,Cattle ,030217 neurology & neurosurgery ,MRI - Abstract
Summary Objective Nuclear magnetic resonance (NMR) spin–lattice relaxation rates were measured in bovine and porcine articular cartilage as a function of water content. Methods Water content was varied by freeze-drying samples for short periods of time (up to 15min). The samples were weighed at all stages of drying so that water content could be quantified. Spin–lattice relaxation rates were measured using magnetic resonance imaging (MRI). Results Linear correlations were observed between relaxation rate and two measures of inverse water content: (1) solid-to-water ratio ( ρ ), expressed as a ratio of the mass of the solid component of the cartilage ( m s ) and the mass of water at each freeze-drying time point ( m w ), and (2) a ratio of the total mass of the fully-hydrated cartilage and m w (1/ w ). These correlations did not appear significantly different for the bovine and porcine data. However, fitting the data to a piecewise-linear model revealed differences between these two species. We interpret the first two segments of the piecewise model as the depletion of different water phases but conjecture that the third segment is partially caused by changes in relaxation rates as a result of a reduction in macromolecular mobilities. Conclusions Whilst we can produce linear correlations which broadly describe the dependence of the measured spin–lattice relaxation rate on (inverse) water content, the linear model seems to obscure a more complicated relationship which potentially provides us with more information about the structure of articular cartilage and its extracellular water.
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- 2012
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62. Native myocardial longitudinal (T1 ) relaxation time: Regional, age, and sex associations in the healthy adult heart
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Samuli M O, Rauhalammi, Kenneth, Mangion, Pauline Hall, Barrientos, David J A, Carrick, Guillaume, Clerfond, John, McClure, Christie, McComb, Aleksandra, Radjenovic, and Colin, Berry
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Male ,Aging ,Sex Characteristics ,healthy volunteer ,Heart Ventricles ,native T1 ,Reproducibility of Results ,Middle Aged ,T1 mapping ,Magnetic Resonance Imaging ,Sensitivity and Specificity ,Ventricular Function, Left ,Cardiac Imaging Techniques ,longitudinal relaxation time ,Reference Values ,myocardium ,Humans ,Female ,Cardiac ,Original Research - Abstract
Purpose To use magnetic resonance imaging (MRI) at two field strengths to assess healthy adults' regional myocardial noncontrast (native) T 1 relaxation time distribution, and global myocardial native T 1 between sexes and across age groups. Materials and Methods In all, 84 healthy volunteers underwent MRI at 1.5T and 3.0T. T 1 maps were acquired in three left ventricular short axis slices using an optimized modified Look–Locker inversion recovery investigational prototype sequence. T 1 measurements in msec were calculated from 16 regions‐of‐interest, and a global T 1 value from all evaluable segments per subject. Associations were assessed with a multivariate linear regression model. Results In total, 1297 (96.5%) segments were evaluable at 1.5T and 1263 (94.0%) segments at 3.0T. Native T 1 was higher in septal than lateral myocardium (1.5T: 956.3 ± 44.4 vs. 939.2 ± 54.2 msec; P < 0.001; 3.0T: 1158.2 ± 45.9 vs. 1148.9 ± 56.9 msec; P = 0.012). Native T 1 decreased with increasing age in females but not in males. Among lowest age tertile (
- Published
- 2015
63. SP538EXPLORATION OF RIGHT VENTRICULAR HAEMODYNAMICS IN HAEMODIALYSIS PATIENTS USING CARDIAC MAGNETIC RESONANCE IMAGING
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Rosemary Woodward, Aleksandra Radjenovic, Allan D. Struthers, Elaine Rutherford, Kenneth Mangion, Christie McComb, Laura Panaro, Patrick B. Mark, and Colin Berry
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Transplantation ,medicine.medical_specialty ,medicine.diagnostic_test ,Nephrology ,Cardiac magnetic resonance imaging ,business.industry ,Internal medicine ,medicine ,Cardiology ,Hemodynamics ,business - Published
- 2017
64. MO050FERUMOXYTOL-ENHANCED MAGNETIC RESONANCE ANGIOGRAPHY FOR THE ASSESSMENT OF PATIENTS WITH COMPLEX ANATOMY DUE FOR VASCULAR ACCESS CREATION
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Martin Hennessy, Aleksandra Radjenovic, Ram Kasthuri, Alex T. Vesey, Giles Roditi, Sokratis Stoumpos, Patrick B. Mark, Peter C. Thomson, and David B. Kingsmore
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Transplantation ,medicine.medical_specialty ,medicine.diagnostic_test ,Nephrology ,business.industry ,Vascular access ,Medicine ,Radiology ,business ,Magnetic resonance angiography - Published
- 2017
65. Endocardial and epicardial myocardial perfusion determined by semi-quantitative and quantitative myocardial perfusion magnetic resonance
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Aleksandra Radjenovic, Sven Plein, Neil Maredia, Stephen G. Ball, John D Biglands, Abdulghani M Larghat, John P Greenwood, and Michael Jerosch-Herold
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Adult ,Gadolinium DTPA ,Male ,medicine.medical_specialty ,Adenosine ,Time Factors ,Vasodilator Agents ,Contrast Media ,Magnetic Resonance Imaging, Cine ,Hemodynamics ,Ventricular Function, Left ,Hyperaemia ,Coronary circulation ,Predictive Value of Tests ,Reference Values ,Coronary Circulation ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Endocardium ,Cardiac imaging ,Chi-Square Distribution ,business.industry ,Myocardial Perfusion Imaging ,Blood flow ,medicine.anatomical_structure ,Regional Blood Flow ,Dynamic contrast-enhanced MRI ,Cardiology ,Regression Analysis ,Female ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,Nuclear medicine ,business ,Pericardium ,Perfusion - Abstract
This study aims to quantify subendocardial and subepicardial myocardial blood flow (MBF) from dynamic contrast-enhanced MRI and to compare semi-quantitative and quantitative analysis methods. 17 healthy volunteers (9 males, mean age 34 ± 8) were scanned during adenosine stress and at rest. A “semi-quantitative” myocardial perfusion index (MPI) was calculated based on maximal upslopes of signal intensity-time profiles for a mid-ventricular myocardial slice. In addition, absolute MBF (ml/g/min) was estimated using Fermi-constrained deconvolution. On semi-quantitative analysis, the ratio of subendocardial to subepicardial MPI was 0.98 ± 0.1 at stress and 1.16 ± 0.09 at rest, P < 0.0001. The MPRI (i.e. the ratio of stress over rest MPI) for the subendocardium was 1.54 ± 0.3 versus 1.81 ± 0.35 for the subepicardium, P = 0.03. For quantitative analysis, the ratio of subendocardial to subepicardial MBF was 0.91 ± 0.11 at stress versus 1.17 ± 0.16 at rest, P < 0.0001. The subendocardial MBF reserve was also lower than in the subepicardium (2.6 ± 0.75 vs. 3.32 ± 0.93, P = 0.027). In conclusion, semi-quantitative and quantitative analysis of dynamic contrast-enhanced MRI shows higher subendocardial blood flow at rest and reduced subendocardial perfusion reserve compared to the subepicardium.
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- 2011
66. Evaluation of the effect of myocardial segmentation errors on myocardial blood flow estimates from DCE-MRI
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Aleksandra Radjenovic, Sven Plein, John D Biglands, Abdulghani M Larghat, Roger Boyle, and Derek R. Magee
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Adult ,Male ,genetic structures ,Maximum deviation ,Contrast Media ,Sensitivity and Specificity ,Coronary Circulation ,Image Interpretation, Computer-Assisted ,Healthy volunteers ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Computer vision ,Segmentation ,Mathematics ,Observer Variation ,Contouring ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Myocardium ,Reproducibility of Results ,Magnetic resonance imaging ,Blood flow ,Middle Aged ,Magnetic Resonance Imaging ,Dynamic contrast ,Female ,Artificial intelligence ,business ,Contour error ,Algorithms ,Blood Flow Velocity ,circulatory and respiratory physiology ,Biomedical engineering - Abstract
Quantitative analysis of cardiac dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) perfusion datasets is dependent on the drawing (manually or automatically) of myocardial contours. The required accuracy of these contours for myocardial blood flow (MBF) estimation is not well understood. This study investigates the relationship between myocardial contour errors and MBF errors. Myocardial contours were manually drawn on DCE-MRI perfusion datasets of healthy volunteers imaged in systole. Systematic and random contour errors were simulated using spline curves and the resulting errors in MBF were calculated. The degree of contour error was also evaluated by two recognized segmentation metrics. We derived contour error tolerances in terms of the maximum deviation (MD) a contour could deviate radially from the 'true' contour expressed as a fraction of each volunteer's mean myocardial width (MW). Significant MBF errors were avoided by setting tolerances of MD ≤ 0.4 MW, when considering the whole myocardium, MD ≤ 0.3 MW, when considering six radial segments, and MD ≤ 0.2 MW for further subdivision into endo- and epicardial regions, with the exception of the anteroseptal region, which required greater accuracy. None of the considered segmentation metrics correlated with MBF error; thus, both segmentation metrics and MBF errors should be used to evaluate contouring algorithms.
- Published
- 2011
67. TCT-232 The Glasgow MRI Rotational Atherectomy Study (GlaMoRoS): HSRA PCI is associated with a low rate of peri-procedural MI and a significant improvement in ischemic burden
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Mitchell Lindsay, John Paul Rocchiccioli, Barry Hennigan, David Carrick, David Corcoran, Guillaume Clerfond, Hany Eteiba, Margaret McEntegart, Colin Berry, Aleksandra Radjenovic, Keith G. Oldroyd, and Kenneth Mangion
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medicine.medical_specialty ,business.industry ,Internal medicine ,Conventional PCI ,Peri ,Cardiology ,Medicine ,Rotational atherectomy ,Cardiology and Cardiovascular Medicine ,business ,Surgery - Published
- 2016
68. Construction and validation of anisotropic and orthotropic ventricular geometries for quantitative predictive cardiac electrophysiology
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Godfrey L. Smith, Michael E. Ries, Aleksandra Radjenovic, Stephen Gilbert, Sven Plein, Alan P. Benson, Olivier Bernus, John P Greenwood, Arun V. Holden, Kevin Mohee, Hans Dierckx, Steven Sourbron, and Richard D. Walton
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Physics ,Cardiac electrophysiology ,Orientation (computer vision) ,Mathematical analysis ,Biomedical Engineering ,Biophysics ,Bioengineering ,Articles ,Orthotropic material ,computer.software_genre ,Biochemistry ,Biomaterials ,Voxel ,Fractional anisotropy ,Tensor ,Anisotropy ,computer ,Simulation ,Biotechnology ,Diffusion MRI - Abstract
Reaction–diffusion computational models of cardiac electrophysiology require both dynamic excitation models that reconstruct the action potentials of myocytes as well as datasets of cardiac geometry and architecture that provide the electrical diffusion tensor D , which determines how excitation spreads through the tissue. We illustrate an experimental pipeline we have developed in our laboratories for constructing and validating such datasets. The tensor D changes with location in the myocardium, and is determined by tissue architecture. Diffusion tensor magnetic resonance imaging (DT-MRI) provides three eigenvectors e i and eigenvalues λ i at each voxel throughout the tissue that can be used to reconstruct this architecture. The primary eigenvector e 1 is a histologically validated measure of myocyte orientation (responsible for anisotropic propagation). The secondary and tertiary eigenvectors ( e 2 and e 3 ) specify the directions of any orthotropic structure if λ 2 is significantly greater than λ 3 —this orthotropy has been identified with sheets or cleavage planes. For simulations, the components of D are scaled in the fibre and cross-fibre directions for anisotropic simulations (or fibre, sheet and sheet normal directions for orthotropic tissues) so that simulated conduction velocities match values from optical imaging or plunge electrode experiments. The simulated pattern of propagation of action potentials in the models is partially validated by optical recordings of spatio-temporal activity on the surfaces of hearts. We also describe several techniques that enhance components of the pipeline, or that allow the pipeline to be applied to different areas of research: Q ball imaging provides evidence for multi-modal orientation distributions within a fraction of voxels, infarcts can be identified by changes in the anisotropic structure—irregularity in myocyte orientation and a decrease in fractional anisotropy, clinical imaging provides human ventricular geometry and can identify ischaemic and infarcted regions, and simulations in human geometries examine the roles of anisotropic and orthotropic architecture in the initiation of arrhythmias.
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- 2010
69. A novel and non-destructive method to examine meniscus architecture using 9.4 Tesla MRI
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Thomas Stapleton, Aleksandra Radjenovic, R. Venkatesh, Eileen Ingham, Samantha P. Williams, M. Wang, John Fisher, and Z M Jin
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musculoskeletal diseases ,Materials science ,Knee Joint ,Swine ,Biomedical Engineering ,Knee Injuries ,Meniscus (anatomy) ,Menisci, Tibial ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Rheumatology ,Cadaver ,medicine ,Animals ,Meniscus ,Orthopedics and Sports Medicine ,030203 arthritis & rheumatology ,medicine.diagnostic_test ,Cartilage ,Brief Report ,Biomechanics ,Structure ,Magnetic resonance imaging ,Anatomy ,musculoskeletal system ,Magnetic Resonance Imaging ,Tibial Meniscus Injuries ,body regions ,medicine.anatomical_structure ,Tears ,MRI - Abstract
Objective\ud To investigate the ability of high-field (9.4 T) magnetic resonance (MR) imaging to delineate porcine knee meniscal tissue structure and meniscal tears.\ud \ud Materials and methods\ud Porcine knees were obtained from a local abattoir, and eight medial menisci with no visible defects were dissected. Lesions simulating longitudinal tears were created on two of the menisci. MR images of the menisci were obtained at 9.4 T using a three-dimensional (3D)-FLASH sequence. A detailed 3D internal architecture of the intact and injured menisci was demonstrated on high-resolution MR images.\ud \ud Results\ud High-resolution 3D MR imaging allowed visualisation of internal architecture of the meniscus and disruption to the internal structural network in damage models. The architecture of the porcine knee meniscus revealed by the MR scans appeared similar to the structures visualised by histology in previously reported studies.\ud \ud Conclusion\ud High-field MRI is a non-destructive technique to examine the internal structural components and damage/wear of meniscal tissue. It has tremendous potential in the field of functional cartilage/meniscus biomechanics and biotribology.
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- 2010
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70. MRI for the assessment and monitoring of RA—what can it tell us?
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Zoe Ash, Paul Emery, Richard Hodgson, Aleksandra Radjenovic, and Dennis McGonagle
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medicine.medical_specialty ,Synovitis ,business.industry ,Disease mechanisms ,Arthritis ,Outcome assessment ,Prognosis ,medicine.disease ,Magnetic Resonance Imaging ,Arthritis, Rheumatoid ,Diagnosis, Differential ,Clinical trial ,Rheumatology ,Rheumatoid arthritis ,Outcome Assessment, Health Care ,Physical therapy ,Humans ,Medicine ,Joints ,Radiology ,Differential diagnosis ,Ultrasonography ,business - Abstract
The past 15 years has seen an exponential rise in the use of MRI for the assessment of rheumatoid arthritis (RA). In this Perspectives article, we review the current and potential future role of MRI in the diagnosis, prognosis and monitoring of RA. We also review the impact of MRI research on the understanding of disease mechanisms. In our view, the pivotal role of synovitis in RA and its predilection for sonographically accessible joints makes it likely that MRI will be used diagnostically in joints that are inaccessible to ultrasonography or where the differential diagnosis is unclear. Additionally, MRI will probably assume an even more prominent role in clinical trials where the aim of therapy is the complete ablation of synovitis. Given the ever-increasing sophistication of MRI, we anticipate that it will continue to be a key research tool in the coming years.
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- 2010
71. Estimates of systolic and diastolic myocardial blood flow by dynamic contrast-enhanced MRI
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John P Greenwood, Stephen G. Ball, Michael Jerosch-Herold, Aleksandra Radjenovic, John D Biglands, Sven Plein, John P. Ridgway, and Abdulghani M Larghat
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medicine.medical_specialty ,Cardiac cycle ,Heart disease ,business.industry ,Pulsatile flow ,Diastole ,Blood flow ,medicine.disease ,Internal medicine ,Dynamic contrast-enhanced MRI ,medicine ,Cardiology ,Radiology, Nuclear Medicine and imaging ,Systole ,business ,Perfusion - Abstract
Myocardial blood flow varies during the cardiac cycle in response to pulsatile changes in epicardial circulation and cyclical variation in myocardial tension. First-pass assessment of myocardial perfusion by dynamic contrast-enhanced MRI is one of the most challenging applications of MRI because of the spatial and temporal constraints imposed by the cardiac physiology and the nature of dynamic contrast-enhanced MRI signal collection. Here, we describe a dynamic contrast-enhanced MRI method for simultaneous assessment of systolic and diastolic myocardial blood flow. The feasibility of this method was demonstrated in a study of 17 healthy volunteers at rest and under adenosine-induced vasodilatory stress. We found that myocardial blood flow was independent of the cardiac phase at rest. However, under adenosine-induced hyperemia, myocardial blood flow and myocardial perfusion reserve were significantly higher in diastole than in systole. Furthermore, the transmural distribution of myocardial blood flow and myocardial perfusion reserve was cardiac phase dependent, with a reversal of the typical subendocardial to subepicardial myocardial blood flow gradient in systole, but not diastole, under stress. The observed difference between systolic and diastolic myocardial blood flow must be taken into account when assessing myocardial blood flow using dynamic contrast-enhanced MRI. Furthermore, targeted assessment of systolic or diastolic perfusion using dynamic contrast-enhanced MRI may provide novel insights into the pathophysiology of ischemic and microvascular heart disease.
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- 2010
72. Magnetic resonance imaging in the assessment of metacarpophalangeal joint disease in early psoriatic and rheumatoid arthritis
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Ai Lyn Tan, Aleksandra Radjenovic, Helena Marzo-Ortega, Paul Emery, Philip O'Connor, Steven F. Tanner, Elizabeth M A Hensor, Philip G. Conaghan, Dennis McGonagle, and Laura A. Rhodes
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Adult ,Gadolinium DTPA ,Male ,medicine.medical_specialty ,Pathology ,Immunology ,Arthritis, Rheumatoid ,Diagnosis, Differential ,Metacarpophalangeal Joint ,Young Adult ,Psoriatic arthritis ,Rheumatology ,Internal medicine ,Synovitis ,Arthropathy ,medicine ,Edema ,Humans ,Immunology and Allergy ,Osteitis ,Aged ,Tenosynovitis ,medicine.diagnostic_test ,business.industry ,Arthritis, Psoriatic ,Magnetic resonance imaging ,General Medicine ,Metacarpophalangeal joint ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Rheumatoid arthritis ,Female ,Radiology ,business ,Joint Capsule - Abstract
The aim of this study was to determine whether magnetic resonance imaging (MRI)-related entheseal changes including osteitis and extracapsular oedema could be used to differentiate between metacarpophalangeal (MCP) joint involvement in rheumatoid arthritis (RA) and psoriatic arthritis (PsA).Twenty patients (10 each with early RA and PsA) had dynamic contrast-enhanced MRI (DCE-MRI) of swollen MCP joints. Synovitis and tenosynovitis was calculated using quantitative analysis including the degree and kinetics of enhancement of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA). Periarticular bone erosion and bone oedema were scored using the Outcome Measures in Rheumatology Clinical Trials (OMERACT) proposals. Entheseal-related features including extracapsular soft tissue enhancement or regions of diffuse bone oedema were also evaluated.MRI was not able to differentiate at the group level between both cohorts on the basis of entheseal-related disease but a subgroup of PsA patients had diffuse extracapsular enhancement (30%) or diffuse bone oedema (20%). The RA patient group had a greater degree of MCP synovitis (p0.0001) and tenosynovitis than PsA patients (p0.0001). There were no significant differences in either the total number of erosions (p = 0.315) or the presence of periarticular bone oedema (p = 0.105) between the groups.Although conventional MRI shows evidence of an enthesitis-associated pathology in the MCP joints in PsA, this is not sufficiently common to be of diagnostic utility.
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- 2009
73. Quantitative Analysis of Dynamic Contrast-Enhanced MRI Datasets of the Metacarpophalangeal Joints
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Aleksandra Radjenovic, Olga Kubassova, and Roger Boyle
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Scanner ,Computer science ,Heuristic ,Dynamic data ,Contrast Media ,Contrast (statistics) ,computer.software_genre ,Magnetic Resonance Imaging ,Metacarpophalangeal Joint ,Dynamic contrast-enhanced MRI ,Humans ,Preprocessor ,Radiology, Nuclear Medicine and imaging ,Data mining ,Heuristics ,computer ,Parametric statistics - Abstract
Rationale and Objectives In this article, we propose an alternative approach to voxel-by-voxel analysis, which overcomes problems associated with heuristic methods currently used for dynamic contrast-enhanced MRI (DCE-MRI) data assessment. We aim to allow fully automated extraction of various heuristic parameters via robust preprocessing methods and a new technique for classification of temporal patterns of contrast agent uptake, making full use of all available dynamic frames of the datasets. We also demonstrate that application of efficient preprocessing methods permits more accurate analysis of the dynamic data. Material and Methods Ten DCE-MRI datasets enhanced by gadolinium diethylene triamine pentacetic acid were acquired from patients with rheumatoid arthritis using a 1.5-T MRI scanner. Fully automated voxel-by-voxel analysis of DCE-MRI signal intensity curves from 60 temporal slices was performed using a new method. Qualitative evaluation of the degree of inflammation was done via constructing parametric maps and quantitative by computing various heuristics such as maximum rate of enhancement, initial rate of enhancement, and time of onset of enhancement. Results Quantitative and qualitative evaluation obtained for 10 DCE-MRI datasets is presented. We demonstrate that preprocessing techniques compensate for patient movement, contribute to data fidelity and therefore permit more robust estimation of various heuristics such as maximum rate of enhancement, initial rate of enhancement, and time of onset of enhancement. Automatically generated parametric maps of these heuristics show favorable characteristics, permitting easier differentiation of structures of interest. These results are free from the subjective input and therefore easily reproducible. Furthermore, the proposed classification scheme provides information on the pattern of contrast uptake previously unavailable. Conclusion Our preliminary results demonstrate the potential of the proposed method for providing objective quantitative and qualitative assessment of DCE-MRI in the metacarpophalangeal joints. Further evaluation within a clinical setting is needed to examine the method’s diagnostic utility.
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- 2007
74. Evidence for a different anatomic basis for joint disease localization in polymyalgia rheumatica in comparison with rheumatoid arthritis
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Helena Marzo-Ortega, Elizabeth M A Hensor, Colin T. Pease, Steven F. Tanner, Aleksandra Radjenovic, Ai Lyn Tan, Paul Emery, Philip O'Connor, Laura A. Rhodes, Dennis McGonagle, and Philip G. Conaghan
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Adult ,Male ,musculoskeletal diseases ,medicine.medical_specialty ,Pathology ,Immunology ,Arthritis ,Arthritis, Rheumatoid ,Metacarpophalangeal Joint ,Polymyalgia rheumatica ,Rheumatology ,Synovitis ,Internal medicine ,Arthropathy ,medicine ,Humans ,Immunology and Allergy ,Pharmacology (medical) ,Aged ,Tenosynovitis ,business.industry ,Metacarpophalangeal joint ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Polymyalgia Rheumatica ,Rheumatoid arthritis ,Female ,Joint Diseases ,business ,Nuclear medicine - Abstract
Objective The anatomic basis for joint disease localization in polymyalgia rheumatica (PMR) is poorly understood. This study used contrast-enhanced and fat suppression magnetic resonance imaging (MRI) to evaluate the relationship between synovial and extracapsular inflammation in PMR and early rheumatoid arthritis (RA). Methods Ten patients with new-onset PMR and 10 patients with early RA underwent dynamic contrast-enhanced MRI and conventional MRI of affected metacarpophalangeal (MCP) joints. Synovitis and tenosynovitis were calculated based on the number of enhancing voxels, initial rate of enhancement, and maximal enhancement of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA). Periarticular bone erosion and bone edema were scored according to the OMERACT (Outcome Measures in Rheumatology Clinical Trials) scoring system in both groups. The degree of extracapsular Gd-DTPA enhancement was assessed in both conditions using semiquantitative scoring. Results No significant differences were seen in the volume of synovitis (P = 0.294), degree of flexor tenosynovitis (P = 0.532), periarticular erosions (P = 0.579), or degree of bone edema (P = 0.143) between RA and PMR joints. However, despite comparable degrees of synovitis, the proportion of MCP joints showing extracapsular enhancement was higher in the PMR group (100%) than in the RA group (50%) (P = 0.030). One PMR patient, but none of the RA patients, had bone edema at the capsular insertion. Conclusion Despite degrees of synovitis and tenosynovitis comparable with those in RA, PMR-related hand disease is associated with prominent extracapsular changes, suggesting that inflammation in these tissues is more prominent than joint synovitis, which is common in both conditions. This suggests that the anatomic basis for joint disease localization differs between RA and PMR.
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- 2007
75. Assessment of Fractional Flow Reserve in Patients With Recent Non–ST-Segment–Elevation Myocardial Infarction
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Jamie Layland, Aleksandra Radjenovic, John D. McClure, Mark C. Petrie, David Carrick, Hany Eteiba, Arvind Sood, Mitchell Lindsay, Vannesa Teng Yue May, Anna O’Donnell, Matthew M.Y. Lee, Colin Berry, Stuart Watkins, Nadeem Ahmed, Keith G. Oldroyd, Margaret McEntegart, and Samuli M Rauhalammi
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Male ,medicine.medical_specialty ,Acute coronary syndrome ,medicine.medical_treatment ,Myocardial Infarction ,Fractional flow reserve ,Coronary artery disease ,Electrocardiography ,Myocardial perfusion imaging ,Cardiac magnetic resonance imaging ,Internal medicine ,Myocardial Revascularization ,medicine ,Humans ,Myocardial infarction ,Aged ,Ejection fraction ,medicine.diagnostic_test ,business.industry ,Myocardial Perfusion Imaging ,Percutaneous coronary intervention ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Fractional Flow Reserve, Myocardial ,Treatment Outcome ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background— The use of fractional flow reserve (FFR) in acute coronary syndromes is controversial. The British Heart Foundation Fractional Flow Reserve Versus Angiography in Guiding Management to Optimize Outcomes in Non-ST-Elevation Myocardial Infarction (FAMOUS-NSTEMI) study (NCT01764334) has recently demonstrated the safety and feasibility of FFR measurement in patients with non–ST-segment–elevation myocardial infarction. We report the findings of the cardiac magnetic resonance (CMR) substudy to assess the diagnostic accuracy of FFR compared with 3.0-T stress CMR perfusion. Methods and Results— One hundred six patients with non–ST-segment–elevation myocardial infarction who had been referred for early invasive management were included from 2 centers. FFR was measured in all major patent epicardial coronary arteries with a visual stenosis estimated at ≥30%, and if percutaneous coronary intervention was performed, an FFR assessment was repeated. Myocardial perfusion was assessed with stress perfusion CMR at 3 T. The mean age was 56.7±9.8 years; 82.6% were men. Mean time from FFR evaluation to CMR was 6.1±3.1 days. The mean±SD left ventricular ejection fraction was 58.2±9.1%. Mean infarct size was 5.4±7.1%, and mean troponin concentration was 5.2±9.2 μg/L. There were 34 fixed and 160 inducible perfusion defects. There was a negative correlation between the number of segments with a perfusion abnormality and FFR ( r =−0.77; P P Conclusions— FFR in patients with recent non–ST-segment–elevation myocardial infarction showed high concordance with myocardial perfusion in matched territories as revealed by 3.0-T stress perfusion CMR. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT02073422.
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- 2015
76. PATHOPHYSIOLOGY OF MYOCARDIAL REMODELING IN SURVIVORS OF ST-ELEVATION MYOCARDIAL INFARCTION: INFLAMMATION, REMOTE MYOCARDIUM AND PROGNOSIS
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Mitchell Lindsay, Aleksandra Radjenovic, Sam Rauhalammi, Stuart Watkins, Hany Eteiba, Nadeem Ahmed, Ahmed Mahrous, Caroline Haig, Mark C. Petrie, Margaret McEntegart, Keith G. Oldroyd, Ian Ford, Colin Berry, Ify Mordi, Stuart Hood, Niko Tzemos, and David Carrick
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medicine.medical_specialty ,business.industry ,Inflammation ,Pathophysiology ,St elevation myocardial infarction ,Internal medicine ,cardiovascular system ,Cardiology ,Medicine ,cardiovascular diseases ,medicine.symptom ,business ,Cardiac magnetic resonance ,Cardiology and Cardiovascular Medicine - Abstract
The significance of remote myocardium in the natural history of STEMI is uncertain. Cardiac magnetic resonance (CMR) depicts left ventricular (LV) dimension and pathology. Native T1 quantified by CMR (T1 proton relaxation time, milliseconds) is a fundamental tissue property determined by water
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- 2015
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77. Quantitative myocardial perfusion performs as well as visual analysis in diagnosing myocardial ischaemia: a CE-MARC sub-study
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John D Biglands, John P Greenwood, Derek R. Magee, Aleksandra Radjenovic, Sven Plein, and Montasir Ibraheem
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Medicine(all) ,Contouring ,medicine.medical_specialty ,Myocardial ischaemia ,Radiological and Ultrasound Technology ,Receiver operating characteristic ,business.industry ,Area under the curve ,Retrospective cohort study ,Bioinformatics ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Poster Presentation ,medicine ,Cardiology ,Radiology, Nuclear Medicine and imaging ,Arterial input function ,Cardiology and Cardiovascular Medicine ,business ,Perfusion ,Angiology - Abstract
Methods This was a retrospective study using a 128 patient subsample of patients, selected from the CE-MARC study such that the distribution of risk factors and disease status within the sample was representative of the full study population. Both visual and quantitative analysis were carried out using the AHA standardised 16 segment model. Visual analysis was part of the original CE-MARC study and was performed by 2 expert reviewers in consensus. To obtain qMBF estimates, manual contouring of the myocardium was carried out and individual qMBF estimates were obtained for each AHA segment using Fermi-constrained deconvolution. The arterial input function was taken from the left ventricular blood pool of the basal slice. Myocardial perfusion reserve values were calculated on a segment by segment basis by dividing the stress by the rest qMBF. The reference standard for myocardial ischaemia was a quantitative coronary X-ray angiogram (QCA) score of ≥70% in any of the coronary territories, or ≥50% in the left main stem. Diagnostic performance was calculated using receiver operator characteristic (ROC) curve analysis. For visual analysis the summed score from all AHA segments was used as the diagnostic measure. For quantitative analysis the minimum MPR value from the AHA segments was used. A DeLong, DeLong, ClarkePearson analysis was performed to test for a statistically significant difference in the area under the curve (AUC) values between visual and quantitative analysis.
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- 2015
78. Prognostic significance of infarct core pathology revealed by quantitative non-contrast in comparison with contrast cardiac magnetic resonance imaging in reperfused ST-elevation myocardial infarction survivors
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David, Carrick, Caroline, Haig, Sam, Rauhalammi, Nadeem, Ahmed, Ify, Mordi, Margaret, McEntegart, Mark C, Petrie, Hany, Eteiba, Stuart, Hood, Stuart, Watkins, Mitchell, Lindsay, Ahmed, Mahrous, Ian, Ford, Niko, Tzemos, Naveed, Sattar, Paul, Welsh, Aleksandra, Radjenovic, Keith G, Oldroyd, and Colin, Berry
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Male ,Ventricular Remodeling ,Cardiac Volume ,Myocardial Reperfusion ,Stroke Volume ,Kaplan-Meier Estimate ,Middle Aged ,Percutaneous Coronary Intervention ,Treatment Outcome ,Coronary Occlusion ,Microvessels ,Humans ,ST Elevation Myocardial Infarction ,Female ,Prospective Studies ,Biomarkers ,Magnetic Resonance Angiography - Abstract
To assess the prognostic significance of infarct core tissue characteristics using cardiac magnetic resonance (CMR) imaging in survivors of acute ST-elevation myocardial infarction (STEMI).We performed an observational prospective single centre cohort study in 300 reperfused STEMI patients (mean ± SD age 59 ± 12 years, 74% male) who underwent CMR 2 days and 6 months post-myocardial infarction (n = 267). Native T1 was measured in myocardial regions of interest (n = 288). Adverse remodelling was defined as an increase in left ventricular (LV) end-diastolic volume ≥20% at 6 months. All-cause death or first heart failure hospitalization was a pre-specified outcome that was assessed during follow-up (median duration 845 days). One hundred and sixty (56%) patients had a hypo-intense infarct core disclosed by native T1. In multivariable regression, infarct core native T1 was inversely associated with adverse remodelling [odds ratio (95% confidence interval (CI)] per 10 ms reduction in native T1: 0.91 (0.82, 0.00); P = 0.061). Thirty (10.4%) of 288 patients died or experienced a heart failure event and 13 of these events occurred post-discharge. Native T1 values (ms) within the hypo-intense infarct core (n = 160 STEMI patients) were inversely associated with the risk of all-cause death or first hospitalization for heart failure post-discharge (for a 10 ms increase in native T1: hazard ratio 0.730, 95% CI 0.617, 0.863; P0.001) including after adjustment for left ventricular ejection fraction, infarct core T2 and myocardial haemorrhage. The prognostic results for microvascular obstruction were similar.Infarct core native T1 represents a novel non-contrast CMR biomarker with potential for infarct characterization and prognostication in STEMI survivors. Confirmatory studies are warranted. CLINICALTRIALS.NCT02072850.
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- 2015
79. Role of vascular channels as a novel mechanism for subchondral bone damage at cruciate ligament entheses in osteoarthritis and inflammatory arthritis
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D. A. Binks, Melissa M. Matzelle, Richard Hodgson, Dennis McGonagle, Aleksandra Radjenovic, Ai Lyn Tan, Ellen M. Gravallese, and Diane Bergin
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Cartilage, Articular ,Male ,Pathology ,Knee Joint ,Inflammatory arthritis ,Arthritis ,Osteoarthritis ,marrow lesions ,Mice ,Immunology and Allergy ,Anterior Cruciate Ligament ,Basic and Translational Research ,Middle Aged ,Osteoarthritis, Knee ,musculoskeletal system ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Female ,erosions ,medicine.medical_specialty ,Anterior cruciate ligament ,Immunology ,Rheumatoid Arthritis ,cartilage loss ,General Biochemistry, Genetics and Molecular Biology ,Bone and Bones ,Cruciate ligament ,Knee Osteoarthritis ,Rheumatology ,expression ,medicine ,Animals ,Humans ,Aged ,Inflammation ,hand osteoarthritis ,business.industry ,Enthesis ,medicine.disease ,Arthritis, Experimental ,rats ,Posterior cruciate ligament ,rheumatoid-arthritis ,Blood Vessels ,Cortical bone ,Posterior Cruciate Ligament ,business ,edema - Abstract
ObjectivesThe purpose of this work was to test whether normal peri-entheseal vascular anatomy at anterior and posterior cruciate ligaments (ACL and PCL) was associated with distribution of peri-entheseal bone erosion/bone marrow lesions (BMLs) in inflammatory arthritis (IA) and osteoarthritis (OA).MethodsNormal microanatomy was defined histologically in mice and by 3 T MRI and histology in 21 cadaveric knees. MRI of 89 patients from the Osteoarthritis Initiative and 27 patients with IA was evaluated for BMLs at ACL and PCL entheses. Antigen-induced arthritis (AIA) in mice was evaluated to ascertain whether putative peri-entheseal vascular regions influenced osteitis and bone erosion.ResultsVascular channels penetrating cortical bone were identified in knees of non-arthritic mice adjacent to the cruciate ligaments. On MRI of normal cadavers, vascular channels adjacent to the ACL (64% of cases) and PCL (71%) entheses were observed. Histology of 10 macroscopically normal cadaveric specimens confirmed the location of vascular channels and associated subclinical changes including subchondral bone damage (80% of cases) and micro-cyst formation (50%). In the AIA model, vascular channels clearly provided a site for inflammatory tissue entry and osteoclast activation. MRI showed BMLs in the same topographic locations in both patients with early OA (41% ACL, 59% PCL) and IA (44%, 33%).ConclusionThe findings show that normal ACL and PCL entheses have immediately adjacent vascular channels which are common sites of subtle bone marrow pathology in non-arthritic joints. These channels appear to be key determinants in bone damage in inflammatory and degenerative arthritis.
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- 2015
80. Prognostic significance of quantitative measures of myocardial infarct pathology using native T1 mapping, in survivors of ST-elevation myocardial infarction
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Aleksandra Radjenovic, Mitchell Lindsay, Margaret McEntegart, Ian Ford, David Carrick, Stuart Watkins, Samuli M Rauhalammi, Colin Berry, Caroline Haig, Mark C. Petrie, Stuart Hood, Ahmed Marous, Hany Eteiba, Keith G. Oldroyd, Ify Mordi, Niko Tzemos, and Nadeem Ahmed
- Subjects
Medicine(all) ,medicine.medical_specialty ,Ejection fraction ,Radiological and Ultrasound Technology ,business.industry ,Hazard ratio ,medicine.disease ,equipment and supplies ,Internal medicine ,Heart failure ,medicine ,Cardiology ,cardiovascular system ,Oral Presentation ,Radiology, Nuclear Medicine and imaging ,Myocardial infarction ,cardiovascular diseases ,Cardiology and Cardiovascular Medicine ,Ventricular remodeling ,business ,human activities ,TIMI ,Killip class ,Angiology - Abstract
Background: Myocardial longitudinal relaxation time (T1, ms) is a fundamental magnetic property of tissue that is related to water content and mobility. The pathophysiological and prognostic importance of native myocardial T1 values in acute STEMI patients is unknown. We aimed to assess the clinical significance of infarct tissue characteristics using native T1 cardiac magnetic resonance (CMR).\ud \ud Methods: We performed a prospective single center cohort study in reperfused STEMI patients who underwent CMR 2 days and 6 months post-MI. Native T1 CMR (MOLLI investigational prototype sequence: 3 (3) 3 (3) 5) was measured in myocardial regions-of-interest. The area-at-risk and infarct territory were depicted with T1 mapping and late gadolinium contrast enhancement imaging, respectively. All-cause death or heart failure hospitalization was a pre-specified outcome that was assessed during follow-up.\ud \ud Results: 300 STEMI patients (mean±SD age 59±12 years, 74% male, 114 with anterior STEMI) gave informed consent and had CMR (14 July 2011 - 22 November 2012). Of these, 288 STEMI patients had evaluable T1 maps and follow-up assessments (median duration 845 days). Infarct size was 18 ±14% of left ventricular mass. Microvascular obstruction occurred in 160 (55.6%) patients. Native T1 within the area-at-risk (1097 ±52 ms) was higher than in the remote zone (961 ±25 ms; p
- Published
- 2015
81. Prognostic significance of infarct core pathology in ST-elevation myocardial infarction survivors revealed by non-contrast T1 mapping cardiac magnetic resonance
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Hany Eteiba, Stuart Watkins, Caroline Haig, Mark C. Petrie, David Carrick, Stuart Hood, Ify Mordi, Ahmed Marous, Niko Tzemos, Colin Berry, Samuli M Rauhalammi, Ian Ford, Aleksandra Radjenovic, Margaret McEntegart, Mitchell Lindsay, Keith G. Oldroyd, and Nadeem Ahmed
- Subjects
Medicine(all) ,medicine.medical_specialty ,Pathology ,Ejection fraction ,Radiological and Ultrasound Technology ,business.industry ,Hazard ratio ,medicine.disease ,Blood pressure ,Internal medicine ,Heart failure ,medicine ,Cardiology ,Oral Presentation ,Radiology, Nuclear Medicine and imaging ,Myocardial infarction ,cardiovascular diseases ,Cardiology and Cardiovascular Medicine ,business ,TIMI ,Angiology ,Killip class - Abstract
Background:\ud Myocardial longitudinal relaxation time (T1, ms) is a fundamental magnetic property of tissue that is related to water content and mobility. The pathophysiological and prognostic importance of native myocardial T1 values in acute ST-elevation myocardial infarction (STEMI) patients is unknown. We aimed to assess the clinical significance of infarct core native T1.\ud Methods:\ud We performed a prospective single center cohort study in reperfused STEMI patients who underwent CMR 2 days and 6 months post-MI. Native T1 CMR (MOLLI investigational prototype sequence: 3 (3) 3 (3) 5) was measured in myocardial regions-of-interest. The infarct territory and microvascular obstruction (MVO) were depicted with late gadolinium enhancement CMR. Adverse remodeling was defined as an increase in LV end-diastolic volume (LVEDV) ≥ 20% at 6 months. All-cause death or heart failure hospitalization was a pre-specified outcome that was assessed during follow-up.\ud \ud Results:\ud 300 STEMI patients (mean±SD age 59±12 years, 74% male, 114 with anterior STEMI) gave informed consent and had CMR (14 July 2011 - 22 November 2012). Of these, 288 STEMI patients had evaluable T1 maps. Infarct size was 18 ±14% of LV mass. One hundred and forty five (50%) of 288 patients had late MVO, whereas 160 (56%) patients had infarct core pathology revealed by native T1. Native T1 within the infarct core (996.9±57.3; p
- Published
- 2015
82. A method for pharmacokinetic modelling of dynamic contrast enhanced MRI studies of rapidly enhancing lesions acquired in a clinical setting
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Michael A. Smith, Aleksandra Radjenovic, and John P. Ridgway
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Pathology ,medicine.medical_specialty ,Metabolic Clearance Rate ,media_common.quotation_subject ,Contrast Media ,Vascular permeability ,Models, Biological ,Microcirculation ,Pharmacokinetics ,Image Interpretation, Computer-Assisted ,Extracellular fluid ,medicine ,Animals ,Humans ,Contrast (vision) ,Computer Simulation ,Tissue Distribution ,Radiology, Nuclear Medicine and imaging ,media_common ,Neovascularization, Pathologic ,Radiological and Ultrasound Technology ,business.industry ,Sigmoid function ,Image Enhancement ,Magnetic Resonance Imaging ,Dynamic contrast-enhanced MRI ,Bolus (digestion) ,business ,Biomedical engineering - Abstract
Abnormal microcirculation is a feature of many neoplastic and non-neoplastic diseases. Physiological variables that characterize tissue microcirculation (capillary permeability and the volume of the extravascular extracellular fluid) are altered in pathological states. Pharmacokinetic analysis of dynamic contrast enhanced MRI (DCE-MRI) has found a widespread use in the assessment of abnormal microcirculation due to the direct link between the contrast agent kinetics and underlying microcirculatory properties. A representation of temporal variation of contrast agent concentration in blood plasma (C(p)(t)) is central to this analysis. In clinical applications of DCE-MRI, signal intensity curves derived from rapidly enhancing lesions often display a sigmoid shape during the initial phase of contrast uptake and rapid arrival at the equilibrium phase. In this work, the features of two principal methods for pharmacokinetic analysis of DCE-MRI which allow for theoretical representation of C(p)(t) are examined and combined to improve analysis of this particular class of DCE-MRI curves. The proposed method allows the representation of the initial sigmoid part of the enhancement profiles whilst retaining a realistic representation of C(p)(t) based on previously published measurements obtained in healthy volunteers. The results of the computer simulations indicate that in rapidly enhancing lesions, with the transfer constant K(trans) greater than 0.1 min(-1), the DCE-MRI acquisition can be restricted to 5 min post-injection and a mono-exponential representation of C(p)(t) decay is sufficient. Furthermore, non-ideal bolus delivery can be represented as a short constant rate infusion when the tissue under investigation exhibits a sigmoid pattern of contrast uptake.
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- 2006
83. Pathophysiology of LV Remodeling in Survivors of STEMI: Inflammation, Remote Myocardium, and Prognosis
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David, Carrick, Caroline, Haig, Sam, Rauhalammi, Nadeem, Ahmed, Ify, Mordi, Margaret, McEntegart, Mark C, Petrie, Hany, Eteiba, Mitchell, Lindsay, Stuart, Watkins, Stuart, Hood, Andrew, Davie, Ahmed, Mahrous, Naveed, Sattar, Paul, Welsh, Niko, Tzemos, Aleksandra, Radjenovic, Ian, Ford, Keith G, Oldroyd, and Colin, Berry
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Male ,Ventricular Remodeling ,Multivariate Analysis ,Myocardial Infarction ,Humans ,Female ,Myocardial Reperfusion Injury ,Middle Aged ,Prognosis ,Magnetic Resonance Imaging ,Follow-Up Studies - Abstract
The aim of this study was to investigate the clinical significance of native T1 values in remote myocardium in survivors of acute ST-segment elevation myocardial infarction (STEMI).The pathophysiology and prognostic significance of remote myocardium in the natural history of STEMI is uncertain. Cardiac magnetic resonance (CMR) reveals myocardial function and pathology. Native T1 (relaxation time in ms) is a fundamental magnetic resonance tissue property determined by water content and cellularity.A total of 300 STEMI patients (mean age 59 years; 74% male) gave informed consent. A total of 288 STEMI patients had evaluable native T1 CMR, and 267 patients (91%) had follow-up CMR at 6 months. Health outcome information was obtained for all of the participants (median follow-up 845 days). Infarct size was 18 ± 13% of left ventricular (LV) mass. Two days post-STEMI, native T1 was lower in remote myocardium than in the infarct zone (961 ± 25 ms vs. 1,097 ± 52 ms; p 0.01). In multivariable regression, incomplete ST-segment resolution was associated with myocardial remote zone native T1 (regression coefficient 9.42; 95% confidence interval [CI]: 2.37 to 16.47; p = 0.009), as were the log of the admission C-reactive protein concentration (3.01; 95% CI: 0.016 to 5.85; p = 0.038) and the peak monocyte count (10.20; 95% CI: 0.74 to 19.67; p = 0.035). Remote T1 at baseline was associated with log N-terminal pro-B-type natriuretic peptide at 6 months (0.01; 95% CI: 0.00 to 0.02; p = 0.002; n = 151) and the change in LV end-diastolic volume from baseline to 6 months (0.13; 95% CI: 0.01 to 0.24; p = 0.035). Remote zone native T1 was independently associated with post-discharge major adverse cardiac events (n = 20 events; hazard ratio: 1.016; 95% CI: 1.000 to 1.032; p = 0.048) and all-cause death or heart failure hospitalization (n = 30 events during admission and post-discharge; hazard ratio: 1.014; 95% CI: 1.000 to 1.028; p = 0.049).Reperfusion injury and inflammation early post-MI was associated with remote zone T1, which in turn was independently associated with LV remodeling and adverse cardiac events post-STEMI. (Detection and Significance of Heart Injury in ST Elevation Myocardial Infarction [BHF MR-MI]; NCT02072850).
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- 2014
84. T1 measurement using a short acquisition period for quantitative cardiac applications
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Aleksandra Radjenovic, David M. Higgins, John P. Ridgway, U. Mohan Sivananthan, and Michael A. Smith
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medicine.medical_specialty ,medicine.diagnostic_test ,Cardiac cycle ,business.industry ,Computer science ,media_common.quotation_subject ,Image registration ,Hemodynamics ,Magnetic resonance imaging ,General Medicine ,Iterative reconstruction ,Range (statistics) ,Medical imaging ,medicine ,Curve fitting ,Contrast (vision) ,Computer vision ,Radiology ,Artificial intelligence ,business ,Perfusion ,media_common - Abstract
Myocardial signal intensity curves for myocardial perfusion studies may be made quantitative by the use of T1 measurements made after the first-pass of contrast agent. A short data acquisition method for T1 mapping is presented in which all data for each T1 map are acquired in a short breath hold, and the slice geometry and timing in the cardiac cycle exactly match that of the dynamic first-pass perfusion sequence. This allows accurate image registration of the T1 map with the first-pass series of images. The T1 method is based on varying the preparation-pulse delay time of a saturation recovery sequence, and in this implementation employs an ECG-triggered, single-shot, spoiled gradient echo technique with SENSE reconstruction. The method allows T1 estimates of three slices to be made in fifteen heartbeats. For a range of samples with T1 values equivalent to those found in the myocardium during the first-pass of contrast agent, T1 estimates were accurate to within 6%, and the variation between slices was 2% or less.
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- 2005
85. Coronary Artery Disease: Myocardial Perfusion MR Imaging with Sensitivity Encoding versus Conventional Angiography
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Aleksandra Radjenovic, Sven Plein, Stephen G. Ball, John P. Ridgway, John P Greenwood, Mohan U. Sivananthan, and David Barmby
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Adult ,Gadolinium DTPA ,Male ,Technology Assessment, Biomedical ,Myocardial Infarction ,Myocardial Ischemia ,Contrast Media ,Coronary Artery Disease ,Coronary Angiography ,Risk Assessment ,Sensitivity and Specificity ,Magnetic resonance angiography ,Coronary artery disease ,Predictive Value of Tests ,Reference Values ,Image Processing, Computer-Assisted ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Myocardial infarction ,Aged ,medicine.diagnostic_test ,Receiver operating characteristic ,business.industry ,Coronary Stenosis ,Gated Blood-Pool Imaging ,Magnetic resonance imaging ,Middle Aged ,medicine.disease ,ROC Curve ,Angiography ,Exercise Test ,Feasibility Studies ,Female ,Myocardial infarction diagnosis ,business ,Nuclear medicine ,Perfusion ,Magnetic Resonance Angiography - Abstract
Purpose To evaluate the technical performance of sensitivity encoding (SENSE)-accelerated myocardial perfusion magnetic resonance (MR) imaging and prospectively assess the diagnostic accuracy of this examination for depiction of significant coronary artery disease (CAD). Materials and methods All 102 subjects provided written informed consent, and the local ethics committee approved the study. A saturation-recovery segmented k-space gradient-echo pulse sequence was combined with SENSE to allow dynamic acquisition of myocardial perfusion data on four parallel short-axis MR image sections at every heartbeat. This technique was evaluated in 10 healthy volunteers and in 92 patients scheduled to undergo conventional coronary angiography. Gadopentetate dimeglumine was peripherally injected at rest and during adenosine-induced stress. The maximal upslope of the signal intensity-time profiles was plotted for 16 myocardial segments defined on three MR image sections, and a myocardial perfusion reserve index (MPRI) between stress and rest, normalized to the input function from the blood pool of the most basal section, was calculated. Areas under receiver operating characteristic curves (AUCs) were used to assess the diagnostic performance of cardiac MR imaging for depiction of greater than 70% CAD seen at coronary angiography, the reference standard. Results In volunteers, the mean myocardial enhancement was 2.1 +/- 1.2 (standard deviation), with homogeneous signal intensity distribution across the segments. The diagnostic accuracy of MPRI measurements was high (AUC, 0.908; sensitivity, 88% [52 of 59 patients]; specificity, 82% [27 of 33 patients]). Diagnostic performance was similar among separate analyses of the three coronary territories and among separate analyses of data in the patients with diabetes mellitus, left ventricular hypertrophy, or myocardial infarction. Conclusion Multisection myocardial perfusion MR imaging with SENSE is feasible and has high diagnostic accuracy in the detection of CAD.
- Published
- 2005
86. 16 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
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Nazia Mohammed, Aleksandra Radjenovic, Colin Berry, Claire Lawless, James Paul, M. Sankaralingham, S. Nowicki, John Bellamy Foster, Jamie Stobo, M. Glegg, Noelle O'Rourke, Naveed Sattar, and Kenneth Mangion
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Cart ,medicine.medical_specialty ,business.industry ,Perfusion index ,medicine.medical_treatment ,medicine.disease ,Surgery ,Radiation therapy ,Basal (phylogenetics) ,Internal medicine ,Cardiology ,medicine ,In patient ,Cardiology and Cardiovascular Medicine ,Lung cancer ,business ,Perfusion ,Semi quantitative - Abstract
Background There are limited data on the cardiac effects of radiotherapy and chemo-radiotherapy on the heart in patients with non-small cell lung cancer (NSCLC). CART is a pilot study designed to investigate change in myocardial function and tissue properties where Patients will undergo cardiac magnetic resonance (CMR) at baseline, during treatment, at 6 weeks and at 6 months after treatment completion. Here we report our preliminary findings related to temporal changes in myocardial perfusion index (MPI). Methods CMR was performed on a Siemens MAGNETOM Verio (Erlangen, Germany) 3.0 Tesla scanner. First-pass myocardial perfusion was assessed by saturation recovery prepared dynamic contrast enhanced sequence during administration of 0.1 mmol/kg of gadoterate meglumine (Dotarem). Semiquantitative analysis was performed on segmented basal and mid-LV short axis slices to derive normalised upslopes of myocardial signal intensity profiles (myocardial perfusion index, MPI). The change in MPI over time was analysed statistically using a linear mixed effects model. Results 13 patients currently have undergone CMR at baseline and during treatment (mean age 66 years, SD: 9; 71% male), 8 patients have undergone CMR at 6 weeks post treatment initiation (5 patients lost to follow-up/ died), and 6 patients have undergone CMR at 6 months from baseline (n = 2 lost to follow-up/ died). Perfusion index (Figure 1) varies significantly with time (p = 0.0015). After adjustment for multiple testing, the increase from baseline is statistically significant at 6 weeks (p = 0.014) and approaches significance at 6 months (p = 0.074) post treatment. Conclusion Change in microvascular perfusion is most pronounced 6 weeks following the completion of treatment. This finding will be used in the design of future clinical studies, where measurement of MPI will provide a robust comparison of different existing and emerging treatment protocols for NSCLC with regard to their effects on myocardial physiology. Funding Beatson Oncology Centre Fund
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- 2016
87. Comparative assessment of leflunomide and methotrexate for the treatment of rheumatoid arthritis, by dynamic enhanced magnetic resonance imaging
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Maarten C. Kraan, Ferdinand C. Breedveld, Paul P. Tak, Aleksandra Radjenovic, P O'Connor, John P. Ridgway, Wayne Gibbon, Douglas J. Veale, Paul Emery, Richard Reece, and Clinical Immunology and Rheumatology
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Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Immunology ,Urology ,Arthritis, Rheumatoid ,chemistry.chemical_compound ,Rheumatology ,Immunopathology ,medicine ,Immunology and Allergy ,Humans ,Pharmacology (medical) ,Prospective Studies ,Leflunomide ,Aged ,Chemotherapy ,Synovitis ,medicine.diagnostic_test ,business.industry ,Magnetic resonance imaging ,Isoxazoles ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Surgery ,Clinical trial ,Methotrexate ,Treatment Outcome ,chemistry ,Rheumatoid arthritis ,Antirheumatic Agents ,Antifolate ,Female ,business ,Immunosuppressive Agents ,medicine.drug - Abstract
Objective Ethical constraints on the conduct of placebo-controlled trials evaluating new therapies for serious chronic diseases, such as rheumatoid arthritis (RA), indicate the need for discerning methods to assess treatment effect in active-controlled clinical trials. Dynamic gadolinium-enhanced magnetic resonance imaging (DEMRI) is a sensitive technique for the detection of synovial inflammation in RA. Therefore, this investigation was undertaken to evaluate DEMRI as an efficacy assessment tool for differentiating treatment effect in a randomized, active-controlled trial comparing leflunomide and methotrexate. Methods Patients with active RA (n = 39) were randomized in a 2-center, prospective, double-blind clinical trial to receive either leflunomide (n = 18) or methotrexate (n = 21) therapy for 4 months. DEMRI scans were obtained at baseline and at 4 months, and the initial rate of enhancement (IRE) and the maximal signal intensity (SI) enhancement (ME) were calculated from the SI curves. Clinical improvement was assessed by conventional outcome measures. Results Thirty-four patients (17 treated with leflunomide and 17 with methotrexate) had usable baseline and end point DEMRI scans. Leflunomide treatment was associated with a significantly greater improvement in IRE compared with methotrexate treatment (P < 0.05). Average values of ME indicated reduction of inflammation with both leflunomide and methotrexate. The improvement in clinical signs and symptoms, as measured by traditional assessments, was comparable for both active treatments. Conclusion Results of this study validate the sensitivity of DEMRI in detecting inflammatory changes in active RA in response to treatment. Improvement in synovial inflammation as measured by IRE was significantly better with leflunomide than with methotrexate over 4 months of therapy.
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- 2002
88. MP817FERUMOXYTOL-ENHANCED MAGNETIC RESONANCE ANGIOGRAPHY FOR THE ASSESSMENT OF POTENTIAL KIDNEY TRANSPLANT RECIPIENTS
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Ram Kasthuri, Martin Hennessy, Sokratis Stoumpos, Aleksandra Radjenovic, David B. Kingsmore, Giles Roditi, Patrick B. Mark, and Alex T. Vesey
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Transplantation ,medicine.medical_specialty ,medicine.diagnostic_test ,Nephrology ,business.industry ,Medicine ,Radiology ,business ,Kidney transplant ,Magnetic resonance angiography - Published
- 2017
89. PROGNOSTIC SIGNIFICANCE OF CO-EXISTING PERSISTENT EDEMA AND HEMORRHAGE AT 6 MONTHS IN SURVIVORS OF ST-ELEVATION MYOCARDIAL INFARCTION
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Colin Berry, Ahmad Mahrous, Stuart Watkins, Ian Ford, Vannesa Teng Yue May, Jaclyn Carberry, Ify Mordi, Margaret McEntegart, Keith G. Oldroyd, Nadeem Ahmed, Stuart Hood, Andrew Davie, David Carrick, Mitchell Lindsay, Aleksandra Radjenovic, Caroline Haig, and Hany Eteiba
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medicine.medical_specialty ,business.industry ,St elevation myocardial infarction ,Internal medicine ,Edema ,Cardiology ,medicine ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business - Published
- 2017
90. CURRENT SMOKING, MICROVASCULAR PATHOLOGY AND ADVERSE OUTCOME AFTER ACUTE ST-SEGMENT ELEVATION MYOCARDIAL INFARCTION: NEW PATHOPHYSIOLOGICAL INSIGHTS
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Stuart Watkins, Ian Ford, Stuart Hood, Aleksandra Radjenovic, Hany Eteiba, Ahmed Mahrous, Naveed Sattar, Nadeem Ahmed, Jaclyn Carberry, David Carrick, Margaret McEntegart, Vannesa Teng Yue May, Ify Mord, Martin Lindsay, Colin Berry, Andrew Davie, Keith G. Oldroyd, Paul Welsh, Caroline Haig, and Mark C. Petrie
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medicine.medical_specialty ,Pathology ,business.industry ,Adverse outcomes ,Acute ST segment elevation myocardial infarction ,medicine.disease ,Pathophysiology ,surgical procedures, operative ,Internal medicine ,Conventional PCI ,Cardiology ,Medicine ,Smoking status ,cardiovascular diseases ,Cardiology and Cardiovascular Medicine ,business ,Reperfusion injury ,Acute STEMI - Abstract
Background: The pathophysiological basis of reperfusion injury in smokers is incompletely understood. Methods: Patients with acute STEMI were prospectively enrolled during emergency PCI, and categorized according to a current smoking status (yes/no). Contrast-enhanced MRI at 1.5T was acquired 2
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- 2017
91. In-vivo assessment of the diagnostic performance of DENSE in patients with myocardial infarction
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Aleksandra Radjenovic, David Carrick, Rosemary Woodward, Christie McComb, John Foster, John D. McClure, and Colin Berry
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Medicine(all) ,medicine.medical_specialty ,Pathology ,Radiological and Ultrasound Technology ,business.industry ,Infarction ,Reference range ,Repeatability ,medicine.disease ,Intensity (physics) ,In vivo ,Poster Presentation ,medicine ,Radiology, Nuclear Medicine and imaging ,cardiovascular diseases ,Myocardial infarction ,Analysis of variance ,Cardiology and Cardiovascular Medicine ,Nuclear medicine ,business ,Angiology - Abstract
Background In patients with myocardial infarction (MI), an important factor in determining the long-term prognosis is the degree of regional contractile dysfunction. DENSE (Displacement ENcoding with Stimulated Echoes) is a technique which allows quantification of myocardial strain[1], and which has been shown to be more sensitive to the presence of late gadolinium enhancement (LGE) than wall thickening measured from cine images[2]. The aim of this study was to further investigate the performance of DENSE for the diagnosis and assessment of myocardial infarction. Methods 50 male patients (age 56 ± 10 years) within 7 days of MI and 30 healthy male controls (age 45 ± 18 years) underwent CMR on a 1.5T Siemens Avanto. The protocol included DENSE and LGE (patients only) obtained from a single mid-ventricular short-axis slice, which was divided into 6 segments for analysis. The percentage of each segment which contained LGE was calculated using a threshold of mean+5SD of remote myocardium intensity. DENSE images were analysed to obtain a value for peak circumferential strain (Ecc). The following analyses were performed: (i) intra- and inter-operator and inter-scan repeatability, (ii) sensitivity and specificity for the detection of LGE, using a reference range established from control data, and ROC analysis and (iii) the ability to distinguish between non-infarcted, 50% infarction, and between remote, adjacent and infarcted segments. Results along with the percentages of segments correctly identified when grouped according to extent of LGE. The reference range was calculated to be (-11.8, -27.0). Inter-operator repeatability was assessed using Levene’s test (variance) and a paired t-test (mean), and no statistically significant differences were found. A paired t-test found no statistically significant difference for inter-scan repeatability. The results of (iii) are illustrated in Figure 1. Comparisons between categories were performed using a one-way ANOVA with Tukey’s post-hoc test. Conclusions DENSE can be successfully applied in a clinical setting, and provides repeatable results. The sensitivity and specificity of the technique for detecting the presence of LGE are good, and the number of segments with LGE correctly identified increases as the extent of LGE increases. Peak
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- 2014
92. Orthogonal invariant sets of the diffusion tensor and the development of a curvilinear set suitable for low-anisotropy tissues
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Zhongmin Jin, Michael E. Ries, Eileen Ingham, Robin A. Damion, and Aleksandra Radjenovic
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lcsh:Medicine ,FOS: Physical sciences ,Condensed Matter - Soft Condensed Matter ,Bioinformatics ,Models, Biological ,Quantitative Biology - Quantitative Methods ,Diffusion Anisotropy ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Fractional anisotropy ,Animals ,Humans ,Physics - Biological Physics ,Invariant (mathematics) ,lcsh:Science ,Anisotropy ,Eigenvalues and eigenvectors ,Quantitative Methods (q-bio.QM) ,Physics ,Curvilinear coordinates ,Multidisciplinary ,lcsh:R ,Mathematical analysis ,Isotropy ,Biological Physics (physics.bio-ph) ,FOS: Biological sciences ,Soft Condensed Matter (cond-mat.soft) ,lcsh:Q ,030217 neurology & neurosurgery ,Research Article ,Diffusion MRI - 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., Comment: 14 pages, 1 table. Published in PLoS ONE (open access) but reformatted here
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- 2014
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93. Automated registration of dynamic contrast enhanced DCE-MRI cardiac perfusion achieves comparable diagnostic accuracy to manual motion correction: a CE-MARC sub-study
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John D Biglands, Aleksandra Radjenovic, Constantine Zakkaroff, Derek R. Magee, John P Greenwood, and Sven Plein
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Medicine(all) ,Contouring ,Radiological and Ultrasound Technology ,business.industry ,Image registration ,Diagnostic accuracy ,Motion correction ,Cardiac perfusion ,Quantitative perfusion ,Dynamic contrast ,Poster Presentation ,Medicine ,Radiology, Nuclear Medicine and imaging ,Computer vision ,Artificial intelligence ,Cardiology and Cardiovascular Medicine ,business ,Perfusion - Abstract
Background The human interaction required for manual motion correction/contouring of cardiac perfusion series remains a significant obstacle to quantitative perfusion gaining a wider acceptance in clinical practice. The use of image registration for motion correction in perfusion data offers a considerable time saving. Numerous registration methods have been proposed, with evaluation limited to the image registration accuracy. However, the important clinical question is how do these methods affect diagnosis? The aim of this study is to evaluate perfusion series registration in terms of its affect on the diagnostic accuracy of myocardial ischaemia.
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- 2014
94. Intra-articular primatised anti-CD4: efficacy in resistant rheumatoid knees. A study of combined arthroscopy, magnetic resonance imaging, and histology
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Richard Reece, P O'Connor, W. J. Parsons, Paul Emery, Aleksandra Radjenovic, Elizabeth Berry, C S Orgles, A.W. Boylston, Douglas J. Veale, John P. Ridgway, U Mason, and Wayne Gibbon
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Adult ,Male ,medicine.medical_specialty ,Knee Joint ,Immunology ,Arthritis ,Placebo ,General Biochemistry, Genetics and Molecular Biology ,Extended Reports ,Injections, Intra-Articular ,Arthritis, Rheumatoid ,Arthroscopy ,Rheumatology ,Synovitis ,Biopsy ,medicine ,Humans ,Immunology and Allergy ,Aged ,medicine.diagnostic_test ,business.industry ,Synovial Membrane ,Antibodies, Monoclonal ,Magnetic resonance imaging ,Middle Aged ,medicine.disease ,Immunohistochemistry ,Magnetic Resonance Imaging ,Surgery ,Treatment Outcome ,medicine.anatomical_structure ,Rheumatoid arthritis ,CD4 Antigens ,Female ,Synovial membrane ,business ,Nuclear medicine - Abstract
OBJECTIVES—CD4+ T cells sustain the chronic synovial inflammatory response in rheumatoid arthritis (RA). SB-210396/CE 9.1 is an anti-CD4 monoclonal antibody that has documented efficacy in RA when given intravenously. This study aimed to establish the safety and efficacy of the intra-articular administration of SB-210396/CE 9.1 compared with placebo, examining its mode of action using a combined imaging approach of arthroscopy, magnetic resonance imaging (MRI), and histology. METHODS—Thirteen RA patients with active, resistant knee synovitis, were randomised to intra-articular injection of placebo (n=3), 0.4 mg (n=3) or 40 mg (n=7) of anti-CD4 after sequential dynamic gadolinium enhanced MRI, followed by same day arthroscopy and synovial membrane biopsy. Imaging and arthroscopic synovial membrane sampling were repeated at six weeks. This study used a unique region of interest (ROI) analysis mapping the MRI area analysed to the specific biopsy site identified arthroscopically, thus providing data for all three modalities at the same synovial membrane site. RESULTS—12 patients completed the study (one placebo treated patient refused further MRI). Arthroscopic improvement was observed in 0 of 2 placebo patients but in 10 of 10 patients receiving active drug (>20% in 6 of 10). Improvement in MRI was consistently observed in all patients of the 40 mg group but not in the other two groups. A reduction in SM CD4+ score was noted in the 40 mg group and in the 0.4 mg group. Strong correlations both before and after treatment, were identified between the three imaging modalities. Intra-articular delivery of SB-210396/CE 9.1 was well tolerated. CONCLUSIONS—SB-210396/CE 9.1 is safe when administered by intra-articular injection. A trend toward efficacy was found by coordinated MRI, arthroscopic, and histological imaging, not seen in the placebo group. The value of ROI analysis was demonstrated.
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- 1999
95. Stepping-Table Gadolinium- enhanced Digital Subtraction MR Angiography of the Aorta and Lower Extremity Arteries: Preliminary Experience
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James F. M. Meaney, David Kessel, Sam Chakraverty, Michael A. Smith, Iain K Robertson, Marc Kouwenhoven, Andrea Kassner, John P. Ridgway, and Aleksandra Radjenovic
- Subjects
Gadolinium DTPA ,Male ,medicine.medical_specialty ,Aortic Diseases ,Contrast Media ,Arterial Occlusive Diseases ,Sensitivity and Specificity ,Magnetic resonance angiography ,Predictive Value of Tests ,medicine.artery ,Occlusion ,Image Processing, Computer-Assisted ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Aorta, Abdominal ,Aged ,Observer Variation ,Leg ,Aorta ,medicine.diagnostic_test ,business.industry ,Abdominal aorta ,Angiography, Digital Subtraction ,Magnetic resonance imaging ,medicine.disease ,Stenosis ,medicine.anatomical_structure ,Subtraction Technique ,Angiography ,cardiovascular system ,Female ,Radiology ,business ,Magnetic Resonance Angiography ,Artery - Abstract
To compare stepping-table digital subtraction gadolinium-enhanced magnetic resonance (MR) angiography of the distal aorta and lower extremity arteries with conventional catheter digital subtraction x-ray angiography in patients with arterio-occlusive disease.Twenty patients underwent both conventional catheter angiography and fast three-dimensional gadolinium-enhanced MR angiography of the aorta and outflow vessels at 1.5 T; the images were acquired in three consecutive imaging locations during a single infusion of a gadolinium chelate.Compared with catheter angiography, according to the findings of two blinded independent reviewers, MR angiography had sensitivities of 81% and 89% and specificities of 91% and 95%, respectively, for demonstration of insignificant (or = 50%) stenosis versus significant (51%-100%) stenosis. For demonstration of occlusion, the sensitivity and specificity were 94% and 97%, respectively, by consensus. There was good interobserver correlation between the two readers overall (kappa = 0.65 for reporting the degree of narrowing in all lesions; 0.86, for reporting of insignificant versus significant stenoses; and 0.928, for reporting of occluded versus patient segments).Stepping-table digital subtraction contrast material-enhanced MR angiography has high accuracy compared with catheter angiography in patients with arterio-occlusive disease of the aorta and outflow vessels. These preliminary study results suggest that this technique may ultimately provide a safe, noninvasive, and cost-effective alternative to catheter angiography.
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- 1999
96. Prevalence and Prognostic Significance of Lipomatous Metaplasia in Patients With Prior Myocardial Infarction
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Roy S. Gardner, Ify Mordi, Colin Berry, Tony Stanton, David Carrick, Nikolaos Tzemos, Aleksandra Radjenovic, and Allan R. McPhaden
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Male ,medicine.medical_specialty ,Pathology ,Time Factors ,Myocardial Infarction ,Magnetic Resonance Imaging, Cine ,Adipose tissue ,Ventricular Function, Left ,Internal medicine ,Metaplasia ,Prevalence ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,cardiovascular diseases ,Myocardial infarction ,Ventricular remodeling ,Prospective cohort study ,Pathological ,Aged ,Ventricular Remodeling ,medicine.diagnostic_test ,business.industry ,Myocardium ,Magnetic resonance imaging ,Middle Aged ,Prognosis ,medicine.disease ,Scotland ,Radiology Nuclear Medicine and imaging ,cardiovascular system ,Cardiology ,Female ,Lipoma ,Electrical conduction system of the heart ,medicine.symptom ,business ,Cardiology and Cardiovascular Medicine - Abstract
It has been noted recently, initially in pathological specimens, that infarcted myocardium can be infiltrated by adipose cells, known as lipomatous metaplasia (LM). It has been suggested that the presence of myocardial fat may interfere with the conduction system of the heart, perhaps providing a
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- 2015
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97. 23 Longitudinal but not circumferential strain is associated with healthy ageing: a strain-encoded cardiac magnetic resonance imaging study at 3.0TESLA: Abstract 23 Table 1
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John D. McClure, Samuli M Rauhalammi, Kenneth Mangion, Guillaume Clerfond, David Corcoran, Aleksandra Radjenovic, David Carrick, Christie McComb, and Colin Berry
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Short axis ,Myocardial tissue ,medicine.diagnostic_test ,business.industry ,Strain (injury) ,medicine.disease ,Cardiac magnetic resonance imaging ,Myocardial strain ,medicine ,Circumferential strain ,Horizontal Long Axis ,Healthy ageing ,Cardiology and Cardiovascular Medicine ,business ,Nuclear medicine - Abstract
Background Displacement encoding with stimulated echoes (DENSE) encodes myocardial tissue displacement into the phase of the MRI image permitting direct quantification of myocardial displacement at multiple cardiac phases. Strain-encoded CMR with DENSE has high spatial (3.2 mm × 3.2 mm × 8 mm) and temporal resolution (TR= 27.34 ms). We aimed to measure myocardial strain values with DENSE in healthy adults across a broad age range at 3.0Tesla. Methods Healthy volunteers with no prior medical history or treatment were enrolled and underwent CMR at 3.0T (Magnetom Verio, Siemens, Erlangen, Germany). Mid-left ventricular short axis and horizontal long axis DENSE sequences were obtained, and analysed using CIM_DENSE2D software (University of Auckland, New Zealand and Siemens Healthcare). Segmental and global myocardial circumferential (Ecc) and longitudinal (Ell) strain were obtained with DENSE. Results 77 participants (mean (SD) age 43.0(16.9) years; range 18–78 years; 40 (52%) males;) were grouped into 3 tertiles according to age. Longitudinal strain differed according to age tertile with strain being greatest in individuals 35–55 years compared to younger or older subjects. There were no differences in Ecc according to age per tertile (Table 1). Conclusion Longitudinal myocardial strain, as revealed by strain-encoded CMR, is associated with chronological age in healthy adults. Funding Medical Research Scotland project grant. Professor Berry was supported by a Senior Clinical Fellowship from the Scottish Funding Council.
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- 2015
98. 5 Relationships between infarct zone extracellular volume and clinical measures of ischaemia and reperfusion in acute STEMI survivors: Abstract 5 Table 1
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David Carrick, Ahmed Mahrous, Ify Mordi, Aleksandra Radjenovic, Nadeem Ahmed, Stuart Watkins, Colin Berry, Hany Eteiba, Caroline Haig, Mark C. Petrie, Ian Ford, Mitchell Lindsay, Jaclyn Carberry, Stuart Hood, Margaret McEntegart, Andrew Davie, Samuli M Rauhalammi, and Keith G. Oldroyd
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Ischemia ,medicine.disease ,Surgery ,surgical procedures, operative ,Cardiac magnetic resonance imaging ,Internal medicine ,Extracellular fluid ,Conventional PCI ,medicine ,Cardiology ,Clinical significance ,cardiovascular diseases ,Myocardial infarction ,Thrombus ,Cardiology and Cardiovascular Medicine ,business ,TIMI - Abstract
Background The clinical significance of infarct extracellular volume (ECV) post-STEMI is unknown. ECV can be estimated by cardiac magnetic resonance imaging (CMR) using T1 MOLLI maps. We measured infarct ECV in STEMI survivors, and assessed the relationships between ECV and markers of MI severity. Methods STEMI survivors were enrolled in a single-centre cohort study (BHF MR-MI study – NCT02072850). Culprit artery flow was described by thrombus in myocardial infarction (TIMI) classification. CMR was performed at 1.5 Tesla (Siemens MAGNETOM Avanto) 2-days and 6-months post-MI, including T1-mapping with MOLLI before and 15-minutes after contrast (0.15 mmol/kg gadoterate meglumine). ECV was analysed by outlining regions-of-interest (ROIs) in infarcted myocardium, including microvascular obstruction, and left ventricular (LV) blood pool. ECV was calculated as the relaxation rate (R1=1/T1) for myocardium and LV blood pool before vs. after contrast, corrected for haematocrit. ECV was compared with TIMI-flow pre- and post-percutaneous coronary intervention (PCI) and ST-segment resolution. A reduction in ST-segment voltage of ≥70% was considered complete ST-resolution and Results 201 STEMI patients (age 58 ± 11 years; 156 (77%) male) were enrolled. Infarct ECV was similar at baseline and follow-up (51.3 ± 9.5% vs. 50.3 ± 12.0%, p = 0.1). Pre-PCI, 131 (65%) patients had TIMI-flow 0 and 70 (35%) had TIMI-flow 1–3. Post-PCI, 3 (1.5%) patients had TIMI-flow 0 and 198 (98.5%) had TIMI-flow 2–3. TIMI-flow 0 pre-PCI was associated with higher infarct ECV at baseline (p Conclusion Preserved culprit artery flow and complete ST-resolution are associated with lower infarct ECV at baseline and follow-up. Clinical and electrocardiographic markers of MI severity are predictors of interstitial expansion in the infarct zone in STEMI patients.
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- 2015
99. Further evidence that a cartilage-pannus junction synovitis predilection is not a specific feature of rheumatoid arthritis
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Andrew J. Grainger, P.G. Conaghan, Dennis McGonagle, Aleksandra Radjenovic, Laura A. Rhodes, and Paul Emery
- Subjects
Cartilage, Articular ,Gadolinium DTPA ,Pathology ,medicine.medical_specialty ,Concise Report ,Immunology ,Contrast Media ,Pannus ,Arthritis ,Osteoarthritis ,General Biochemistry, Genetics and Molecular Biology ,Arthritis, Rheumatoid ,Rheumatology ,Synovitis ,Image Processing, Computer-Assisted ,medicine ,Humans ,Immunology and Allergy ,medicine.diagnostic_test ,business.industry ,Cartilage ,Magnetic resonance imaging ,Patella ,Osteoarthritis, Knee ,equipment and supplies ,medicine.disease ,Magnetic Resonance Imaging ,Connective tissue disease ,medicine.anatomical_structure ,Rheumatoid arthritis ,business ,human activities - Abstract
Qualitative differences in synovitis between the cartilage-pannus junction (CPJ) region and the adjoining suprapatellar pouch (SPP) have been reported in rheumatoid arthritis and the spondyloarthropathies.To determine if the distribution of synovitis is the same in osteoarthritis (OA) using sensitive measures of inflammation derived from dynamic, contrast enhanced magnetic resonance imaging (DEMRI).20 subjects with established OA of the knee were recruited. Conventional MR images together with the DEMRI measurements were obtained. Areas of synovitis at the CPJ region and at a distant site in the SPP were calculated; differences in CPJ and SPP synovitis were determined using DEMRI parameters: the initial rate of contrast enhancement (IRE) and maximal enhancement (ME).The area of synovitis was significantly greater adjacent to the CPJ than in the SPP. IRE and ME measures were greater at the CPJ than the SPP.The magnitude of synovitis at the CPJ is not disease-specific and applies across the spectrum of degenerative disease as well as inflammatory diseases.
- Published
- 2005
100. Quantitative parametric MRI of articular cartilage: a review of progress and open challenges
- Author
-
Stephen W. Smye, Richard Hodgson, D. A. Binks, Richard J. Foster, Dennis McGonagle, Michael E. Ries, and Aleksandra Radjenovic
- Subjects
Cartilage, Articular ,Gadolinium DTPA ,Relaxometry ,Pathology ,medicine.medical_specialty ,Contrast Media ,Articular cartilage ,Osteoarthritis ,Review Article ,Bioinformatics ,Tendons ,medicine ,Quantitative assessment ,Effective treatment ,Animals ,Humans ,Radiology, Nuclear Medicine and imaging ,Ligaments ,Sheep ,business.industry ,Cartilage ,Chondroitin Sulfates ,Sodium ,General Medicine ,Patella ,medicine.disease ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Sodium MRI ,Cattle ,business ,Diffusion MRI - Abstract
With increasing life expectancies and the desire to maintain active lifestyles well into old age, the impact of the debilitating disease osteoarthritis (OA) and its burden on healthcare services is mounting. Emerging regenerative therapies could deliver significant advances in the effective treatment of OA but rely upon the ability to identify the initial signs of tissue damage and will also benefit from quantitative assessment of tissue repair in vivo. Continued development in the field of quantitative MRI in recent years has seen the emergence of techniques able to probe the earliest biochemical changes linked with the onset of OA. Quantitative MRI measurements including T(1), T(2) and T(1ρ) relaxometry, diffusion weighted imaging and magnetisation transfer have been studied and linked to the macromolecular structure of cartilage. Delayed gadolinium-enhanced MRI of cartilage, sodium MRI and glycosaminoglycan chemical exchange saturation transfer techniques are sensitive to depletion of cartilage glycosaminoglycans and may allow detection of the earliest stages of OA. We review these current and emerging techniques for the diagnosis of early OA, evaluate the progress that has been made towards their implementation in the clinic and identify future challenges in the field.
- Published
- 2013
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