Search

Abstract: Flow in the great arteries (aorta, pulmonary artery) is normally laminar with a parabolic velocity profile. Eccentric flow jets are linked to various diseases like aneurysms. Cardiac 4D PC‐MRI data provide spatio‐temporally resolved blood flow information for the whole cardiac cycle. In this work, we establish a time‐dependent visualization and quantification of flow jets. For this purpose, equidistant measuring planes are automatically placed along the vessel's centerline. The flow jet position and region with highest velocities are extracted for every plane in each time step. This is done during pre‐processing and without user‐defined parameters. We visualize the main flow jet as geometric tube. High‐velocity areas are depicted as a net around this tube. Both geometries are time‐dependent and can be animated. Quantitative values are provided during cross‐sectional measuring plane‐based evaluation. Moreover, we offer a plot visualization as summary of flow jet characteristics for the selected plane. Our physiologically plausible results are in accordance with medical findings. Our clinical collaborators appreciate the possibility to view the flow jet in the whole vessel at once, which normally requires repeated pathline filtering due to varying velocities along the vessel course. The overview plots are considered as valuable for documentation purposes. [ABSTRACT FROM AUTHOR]

Objectives: To analyse the value of cardiovascular magnetic resonance (CMR)-derived myocardial parameters to differentiate left ventricular non-compaction cardiomyopathy (LVNC) from other cardiomyopathies and controls.Methods: We retrospectively analysed 12 patients with LVNC, 11 with dilated and 10 with hypertrophic cardiomyopathy and compared them to 24 controls. LVNC patients had to fulfil standard echocardiographic criteria as well as additional clinical and imaging criteria. Cine steady-state free precession and late gadolinium enhancement (LGE) imaging was performed. The total LV myocardial mass index (LV-MMI), compacted (LV-MMI(compacted)), non-compacted (LV-MMI(non-compacted)), percentage LV-MM(non-compacted), ventricular volumes and function were calculated. Data were compared using analysis of variance and Dunnett's test. Additionally, semi-quantitative segmental analyses of the occurrence of increased trabeculation were performed.Results: Total LV-MMI(non-compacted) and percentage LV-MM(non-compacted) were discriminators between patients with LVCN, healthy controls and those with other cardiomyopathies with cut-offs of 15 g/m(2) and 25 %, respectively. Furthermore, trabeculation in basal segments and a ratio of non-compacted/compacted myocardium of ≥3:1 were criteria for LVNC. A combination of these criteria provided sensitivities and specificities of up to 100 %. None of the LVNC patients demonstrated LGE.Conclusions: Absolute CMR quantification of the LV-MMI(non-compacted) or the percentage LV-MM(non-compacted) and increased trabeculation in basal segments allows one to reliably diagnose LVNC and to differentiate it from other cardiomyopathies.Key Points: Cardiac magnetic resonance imaging can reliably diagnose left ventricular non-compaction cardiomyopathy. Differentiation of LVNC from other cardiomyopathies and normal hearts is possible. The best diagnostic performance can be achieved if combined MRI criteria for the diagnosis are used. [ABSTRACT FROM AUTHOR]

Objective: Takotsubo cardiomyopathy (TTC) is an increasingly recognised acute cardiac syndrome, whose underlying pathophysiological mechanisms remain unknown. Inflammation might play a role as this has been shown in endomyocardial biopsies. The aim of this study was to assess inflammatory parameters in patients with TTC using a comprehensive cardiovascular magnetic resonance imaging (CMR) approach.Methods: Thirty-seven patients with the suspected diagnosis of TTC underwent CMR. T2-weighted imaging to calculate the oedema ratio, T1-weighted imaging before and after contrast agent administration to calculate the global relative enhancement (gRE), and late gadolinium enhancement (LGE) imaging were performed.Results: In 11 patients CMR revealed the diagnosis of myocardial infarction (n = 7; 19%) or myocarditis (n = 4; 11%) with typical patterns of LGE. In all other patients (n = 26; 70%), no LGE was detected consistent with the diagnosis of TTC. Of these, in 16 patients (62%) both inflammatory markers (oedema ratio and gRE) were elevated with concomitant pericardial effusion, indicating acute inflammation. Follow-up CMR after 3 months showed complete normalisation of left ventricular function and inflammatory parameters in the absence of LGE and pericardial effusion.Conclusion: This CMR study provides further insights into the pathophysiological mechanisms in TTC, supporting the contribution of an inflammatory process in the acute setting. [ABSTRACT FROM AUTHOR]

Objective: To compare cardiac left ventricular (LV) parameters in simultaneously acquired hybrid fluorine-18-fluorodeoxyglucose ([18F] FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) in patients with residual tracer activity of upstream PET/CT.Methods: Twenty-nine patients (23 men, age 58±17 years) underwent cardiac PET/MRI either directly after a non-cardiac PET/CT with homogenous cardiac [18F] FDG uptake (n=20) or for viability assessment (n=9). Gated cardiac [18F] FDG PET and cine MR sequences were acquired simultaneously and evaluated blinded to the cross-imaging results. Image quality (IQ), end-diastolic (LVEDV), end-systolic volume (LVESV), ejection fraction (LVEF) and myocardial mass (LVMM) were measured. Pearson correlation and intraclass correlation coefficient (ICC), regression and a Bland-Altman analysis were assessed.Results: Except LVMM, volumetric and functional LV parameters demonstrated high correlations (LVESV: r=0.97, LVEDV: r=0.95, LVEF: r=0.91, LVMM: r=0.87, each p<0.05), but wide limits of agreement (LOA) for LVEDV (-25.3-82.5ml); LVESV (-33.1-72.7ml); LVEF (-18.9-14.8%) and LVMM (-78.2-43.2g). Intra- and interobserver reliability were very high (ICC≥0.95) for all parameters, except for MR-LVEF (ICC=0.87). PET-IQ (0-3) was high (mean: 2.2±0.9) with significant influence on LVMM calculations only.Conclusion: In simultaneously acquired cardiac PET/MRI data, LVEDV, LVESV and LVEF show good agreement. However, the agreement seems to be limited if cardiac PET/MRI follows PET/CT and only the residual activity is used.Key Points: • [ 18 F] FDG PET-MRI is feasible with residual [ 18 F] FDG activity in patients with homogenous cardiac uptake. • Cardiac volumes and function assessed by PET/MRI show good agreement. • LVEDV and LVESV are underestimated; PET overestimates LVMM and LVEF. • Cardiac PET and MRI data correlate better when acquired simultaneously than sequentially. • PET and MRI should not assess LV parameters interchangeably. [ABSTRACT FROM AUTHOR]

One of the main concerns in planning a vaginal birth after previous cesarean section is the risk for uterine rupture which is considered to be associated with the wall thickness in the scar area. Assuming the uterine scar to be located within the lower uterine segment (LUS), ultrasound diagnostic with LUS thickness measurement is widely used for prenatal risk assessment. Although intensively investigated there is a strong inhomogeneity of study results and reliable examination protocols and reference values are still missing 1,2 . [ABSTRACT FROM AUTHOR]

Background: No comparisons of different doses of docetaxel-capecitabine in patients with advanced gastric cancer have been performed.Methods: Patients with previously untreated metastatic/locally advanced gastro-oesophageal or gastric adenocarcinoma were enrolled in a prospective multicentre phase II trial. Two sequential cohorts received docetaxel 75 mg m(-2) (day 1) plus capecitabine 1000 mg m(-2) twice daily (days 1-14) (cohort I) or docetaxel 60 mg m(-2) (day 1) plus capecitabine 800 mg m(-2) twice daily (days 1-14) (cohort II) every 3 weeks. The primary end point was confirmed overall response rate.Results: In all, 91 patients were enrolled (cohort I, n=40; cohort II, n=51) and 87 were evaluable for efficacy (n=38, 49, respectively). Overall response rate was 50.0% in cohort I and 23.5% in cohort II (exploratory analysis, P=0.014). Median times to tumour progression and overall survival were 5.6 and 10.1 months in cohort I and 3.7 and 7.2 months in cohort II, respectively. Dose reductions for docetaxel and capecitabine were required in 50.0% and 57.5% of patients in cohort I and 11.8% and 15.7% in cohort II, respectively.Conclusion: Starting treatment with full doses and reducing promptly seems to be the more promisingly effective strategy than starting cautiously with lower doses. Docetaxel/capecitabine 75/2000 mg m(-2) is a manageable, convenient outpatient combination with promising efficacy against advanced gastric cancer. [ABSTRACT FROM AUTHOR]

Objective: To retrospectively assess the prevalence and functional relevance of lipomatous metaplasia (LM) of the left ventricle in patients with chronic ischaemic heart disease (CIHD) using cardiac magnetic resonance imaging (cMRI) with steady state free precession (SSFP) sequences.Methods: We examined 315 patients (248 male, mean age 63 +/- 10 years) with a history of CIHD by cMRI. Standard SSFP sequences were applied and results were correlated with findings from cardiac catheterisation and computed tomography. In a subgroup of patients with LM (LM+) the functional results were correlated with patients without LM (LM-) as controls matched for age, body mass index, gender and infarct size.Results: Of 315 patients, 36 showed LM. LM+ patients showed a higher tendency to develop aneurysms compared with LM- (31% vs. 17%; not significant), but no differences in ejection fraction or volumetric parameters. LM occurred significantly more often in older infarcts and patients with hyperlipoproteinaemia, while other cardiac risk factors or medication did not have a significant influence on the development of LM.Conclusions: LM is a common finding (11%) in patients with CIHD. LM does not have a significant influence on global cardiac function or ventricular size, but on local function and probably also on the development of left ventricular aneurysms. [ABSTRACT FROM AUTHOR]

Cardiovascular MR imaging often requires high temporal and spatial resolution, especially in order to acquire data about cardiac function. Furthermore, the current results at 1.5 T for coronary artery imaging or plaque imaging are still not satisfying even with the use of the latest technology. Therefore, cardiac imaging inherently demands high signal-to-noise (SNR) and contrast-to-noise ratios (CNR) and hence may benefit from higher magnetic field strengths. However, higher magnetic field strengths do not inevitably improve the image quality for all cardiac imaging techniques as compared with their 1.5 T counterparts. At higher magnetic field strengths one has to cope with increased field inhomogeneities, longerT1, shorterT2* relaxation times and radiofrequency power deposition constraints, which require further methodological developments. Initial studies using 3.0 T whole-body scanners for cardiac imaging revealed that optimized steady-state free precession or spin-echo sequences meet the expected SNR increase at 3.0 T but showed different results for CNR. These results are especially encouraging for cardiac tissue characterization at 3 T together with the evolving parallel imaging techniques. This review focuses on the feasibility of cardiac MR imaging at high magnetic field strengths. The pros and cons of cardiac imaging at 3.0 T vs. 1.5 T are examined and technical solutions are discussed. [ABSTRACT FROM AUTHOR]

Aim: To investigate the observer agreement for the assessment of chronic myocarditis by native T1 and T2 relaxation times, post-contrast T1 relaxation time, and extracellular volume (ECV) fraction, compared to Lake Louise Criteria: oedema ratio (OR) and early gadolinium enhancement ratio (EGEr).Materials and Methods: Data were collected retrospectively on 71 consecutive patients who underwent cardiac magnetic resonance imaging as part of a complete diagnostic work-up according to current guidelines for suspected myocarditis. Thirteen cases were excluded due to previous myocardial infarction or technical issues. To test for intra- and interobserver agreement, the determination of the myocardial native T1 and T2 relaxation times, post-contrast T1 relaxation time, ECV, OR and EGEr was undertaken by two medical school graduates after comprehensive training. Bland-Altman analysis and intraclass correlation coefficient (ICC) were assessed.Results: The final analysis included 27 patients with chronic myocarditis, 21 patients with dilated cardiomyopathy and/or hypertensive heart disease, and 10 patients with unremarkable investigations in the control group. Excellent interobserver agreement was obtained for native T1 and T2 relaxation times, post-contrast T1 relaxation time and ECV, with ICC of 0.982/0.977/0.991/0.994, p < 0.001. Interobserver agreement was lower for OR and EGEr, with ICC of 0.841 and 0.818, p < 0.001, respectively. Mapping parameters (cut-off values: T1 1,070 ms, T2 54 ms, ECV 30%) yield good performance in the diagnosis of chronic myocarditis with the best sensitivity/specificity/accuracy of 93%/80%/88% for ECV, followed by 70%/80%/74% for T2, and 52%/88%/69% for T1.Conclusions: mapping parameters show excellent agreement between observers in the assessment of myocarditis. [ABSTRACT FROM AUTHOR]