Assessment of right ventricular diastolic function in pediatric patients with repaired tetralogy of Fallot by cardiovascular magnetic resonance and echocardiography.

OBJECTIVES: Cardiovascular magnetic resonance (CMR) imaging is routinely performed for assessing right ventricular (RV) systolic but not diastolic function. We aimed to investigate CMR-based assessment of RV diastolic function in pediatric patients with repaired tetralogy of Fallot (rTOF), compared to transthoracic echocardiography (TTE) measurements. METHODS: A total of 130 consecutive pediatric patients with rTOF who underwent clinically indicated CMR and same-day TTE were included. Forty-three controls were recruited. Phase-contrast images were used to measure trans-tricuspid valve flow velocities during early (E) and late diastolic (A) phases (measured in cm/s). Feature tracking of the tricuspid annulus was performed to derive early (e') and late diastolic (a') myocardial velocities (measured in cm/s). RV diastolic function was evaluated by E/A ratio, E/e' ratio, and E-wave deceleration time (measured in milliseconds). Regression analyses were utilized to identify potential variables associated with RV diastolic dysfunction (DD). The performance of CMR-derived parameters in diagnosing RV DD was assessed using receiver-operating characteristic analyses. RESULTS: Good agreement was found between CMR and TTE measurements (ICC 0.70-0.89). Patients with RV DD (n = 67) showed significantly different CMR-derived parameters including E and e' velocities, and E/A and E/e' ratio, compared to patients without DD (n = 63) (all p < 0.05). CMR-derived E and e' velocities and E/e' ratio were independent predictors of RV DD. E/e' of 5.8 demonstrated the highest discrimination of RV DD (AUC 0.76, sensitivity 70%, specificity 86%). CONCLUSIONS: CMR-derived parameters showed good agreement with TTE parameters in determining RV DD. CMR-derived E/e' was proved to be the most effective in identifying RV DD. CLINICAL RELEVANCE STATEMENT: This study demonstrated the feasibility and efficacy of CMR in assessing diastolic function in pediatric patients. RV DD was presented in over half of patients according to current TTE guidelines, highlighting the need for assessing RV diastolic function during follow-up. KEY POINTS: • Routinely acquired cine and phase-contrast cardiovascular magnetic resonance (CMR) images yielded right ventricular (RV) diastolic parameters which demonstrated good agreement with transthoracic echocardiography (TTE) measurements. • There was a high prevalence of RV diastolic function impairment in pediatric patients with repaired tetralogy of Fallot (rTOF). • CMR is a reliable complementary modality of TTE for RV diastolic function evaluation.

Coronary CT Angiography-based Morphologic Index for Predicting Hemodynamically Significant Coronary Stenosis.

Purpose To develop a new coronary CT angiography (CCTA)-based index, α×LL/MLD4, that considers lesion entrance angle (α) in addition to lesion length (LL) and minimal lumen diameter (MLD) and to evaluate its efficacy in predicting hemodynamically significant coronary stenosis compared with invasive coronary angiography (ICA)-derived fractional flow reserve (FFR). Materials and Methods This prospective study enrolled participants (September 2016-March 2020) from two centers who underwent CCTA followed by ICA (ClinicalTrials.gov identifier: NCT03054324). CCTA images were processed semiautomatically to measure LL, MLD, and α for calculating α×LL/MLD4. Diagnostic performance and accuracy of α×LL/MLD4 and LL/MLD4 in detecting hemodynamically significant coronary stenosis were compared against the reference standard (invasive FFR ≤ 0.80). Results In total, 133 participants (mean age, 63 years ± 9 [SD]; 99 [74%] men) with 210 stenosed coronary arteries were analyzed. Median α×LL/MLD4 was 54.0 degree/mm3 (IQR, 25.3-128.7) in participants with invasive FFR of 0.80 or less and 6.7 degree/mm3 (IQR, 3.3-12.8) in participants with invasive FFR of more than 0.80 (P < .001). The per-vessel accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for discriminating ischemic lesions were 86.2%, 83.1%, 88.4%, 84.1%, and 87.7% for α×LL/MLD4 and 80.5%, 66.3%, 90.9%, 84.3%, and 78.6% for LL/MLD4, respectively. Area under the receiver operating characteristic curve for discriminating hemodynamically significant stenosis was 0.93 for α×LL/MLD4, which was significantly greater than the values of 0.84 for LL/MLD4 and 0.63 for diameter stenosis (both P < .001). Conclusion The new morphologic index, α×LL/MLD4, incorporating lesion entrance angle achieved higher diagnostic performance in detecting hemodynamically significant lesions compared with diameter stenosis and LL/MLD4. Keywords: CT Angiography, Cardiac, Coronary Arteries, Ischemia, Infarction, Technology Assessment Clinical trial registration no. NCT03054324 Supplemental material is available for this article. © RSNA, 2023 See also the commentary by Fairbairn and Nørgaard in this issue.

Investigating 5-Level EQ-5D (EQ-5D-5L) Values Based on Preferences of Patients With Heart Disease.

OBJECTIVES: Several studies have shown that patients with heart disease value hypothetical health states differently from the general population. We aimed to investigate the health preferences of patients with heart disease and develop a value set for the 5-level EQ-5D (EQ-5D-5L) based on these patient preferences. METHODS: Patients with confirmed heart disease were recruited from 2 hospitals in Singapore. A total of 86 EQ-5D-5L health states (10 per patient) were valued using a composite time trade-off method according to the international valuation protocol for EQ-5D-5L; 20-parameter linear models and 8-parameter cross-attribute level effects models with and without an N45 term (indicating whether any health state dimension at level 4 or 5 existed) were estimated. Each model included patient-specific random intercepts. Model performance was evaluated for out-of-sample and in-sample predictive accuracy in terms of root mean square error. The discriminative ability of the utility values was assessed using heart disease-related functional classes. RESULTS: A total of 576 patients were included in the analysis. The preferred model, with the lowest out-of-sample root mean square error, was a 20-parameter linear model including N45. Predicted utility values ranged from -0.727 for the worst state to 1 for full health; the value for the second-best state was 0.981. Utility values demonstrated good discriminative ability in differentiating among patients of varied functional classes. CONCLUSIONS: An EQ-5D-5L value set representing the preferences of patients with heart disease was developed. The value set could be used for patient-centric economic evaluation and health-related quality of life assessment for patients with heart disease.

Sex differences in assessing stenosis severity between physician visual assessment and quantitative coronary angiography.

BACKGROUND: Physician visual assessment (PVA) in invasive coronary angiography (ICA) is the current clinical method to determine stenosis severity and guide percutaneous coronary intervention. This study sought to evaluate the effect of sex differences in assessing coronary stenosis severity between PVA and quantitative coronary angiography (QCA). METHODS: 209 patients with coronary artery disease (288 coronary lesions) underwent ICA and fractional flow reserve (FFR). ICA image processing including PVA and QCA was used to quantify diameter stenosis (DS). The difference of DS (ΔDS) between PVA and QCA was defined as DSPVA-DSQCA. DS ≥50% was considered anatomically obstructive. FFR ≤0.8 was defined as myocardial ischemia. RESULTS: Mean ± SD age was 63 ± 9 years. There were no significant differences in DSPVA (61.1 ± 16.3% vs 60.1 ± 18.9%) and DSQCA (53.1 ± 12.1% vs 55.4 ± 14.3%) between females and males. However, ΔDS between PVA and QCA was higher in females (8.0 ± 10.9%) than in males (4.7 ± 10.9%) (P = 0.03). Thirty-four of 72 vessels (47.2%) in female patients and 75 of 216 vessels (34.7%) in male patients were classified differently by at least one grade using PVA compared to QCA assessment. DSPVA and DSQCA were negatively correlated with FFR in females (rPVA = -0.397, rQCA = -0.448) with an even stronger negative correlation in males (rPVA = -0.607, rQCA = -0.607). ROC analysis demonstrated that DSQCA had better discrimination capability for myocardial ischemia (FFR ≤ 0.80) than DSPVA in both sexes (P < 0.05). CONCLUSIONS: A systematic bias was found in PVA (QCA reference) for overestimating severity of coronary artery disease in females compared to males.

Familial Hypercholesterolemia in Asia Pacific: A Review of Epidemiology, Diagnosis, and Management in the Region.

Familial hypercholesterolemia (FH) is a common genetic disease that is estimated to affect at least 15 million people in the Asia Pacific region. Affected individuals are at significantly increased risk of premature atherosclerotic cardiovascular disease. A literature review was undertaken to provide an overview of the epidemiology, diagnosis, and management of FH across the region.Currently, epidemiological data relating to FH are lacking across the Asia Pacific. Of the 15 countries and regions considered, locally conducted studies to determine FH prevalence were only identified for Australia, China, India, and Japan. Although practically all national clinical guidelines for dyslipidemia include some commentary on FH, specific guidelines on the management of FH are available for only one third of the countries and regions evaluated. Estimates of current FH diagnosis rates suggest that most affected individuals remain undiagnosed and untreated. Although innovative medications such as proprotein convertase subtilisin/kexin type 9 inhibitors have been approved and are available in most countries and regions considered, they are currently reimbursed in only one quarter.Despite these shortcomings, there is cause for optimism. Early experience with cascade screening in Hong Kong, India, and Vietnam has proven an effective means of identifying family members of probands, as has a reverse screening of family members of children with FH in China. FH registries are gaining momentum across the region, with registries now established in almost half of the countries and regions evaluated. This review concludes with a Call to Action on FH for Asia Pacific to engage healthcare professionals, improve public awareness, and form national FH alliances, comprising all relevant healthcare professional organizations, as a platform to expedite national quality improvement programs in the management of FH.

Age-related changes in four-dimensional CMR-derived atrioventricular junction velocities and displacements: Implications for the identification of altered annular dynamics for ventricular function assessment.

BACKGROUND: We determined the age-related changes in atrioventricular junction (AVJ) velocities and displacements by feature tracking cardiovascular magnetic resonance (FT-CMR) in a healthy community-based population. We also investigated the importance of age-matching for the identification of altered AVJ dynamics. METHODS: FT-CMR was performed in 230 controls (18-78 years) and in two patient groups each consisting of 40 subjects (group 1: 23-55 years, group 2: 56-80 years). AVJ dynamic parameters, including systolic velocity Sm, early diastolic velocity Em, late diastolic velocity Am, maximal systolic excursion MAPSE and the new parameter sweep surface area velocity SSAV were measured. RESULTS: Increasing age in the control group was significantly associated with reductions in Sm, Em, MAPSE (r = -0.40, -0.76, -0.34, all P < 0.001) and an increase in Am (r = 0.45, P < 0.001). For patient group 1, the selection of an age-unmatched control group (56-76 years) underestimated the number of patients with abnormal AVJ dynamics during systole and early diastole (38% vs. 70% for Sm; 20% vs. 60% for Em; 35% vs. 50% for MAPSE). In contrast, for patient group 2, the number of patients with systolic and early diastolic AVJ dynamic abnormalities was overestimated (88% vs. 63% for Sm; 90% vs. 68% for Em; 73% vs. 58% for MAPSE) when compared with age-unmatched controls (24-55 years). Fifty-percent (20/40) of the sub-group of patients with normal left ventricular ejection fraction exhibited abnormal systolic Sm or MAPSE measurements. CONCLUSIONS: Significant correlations exist between age and AVJ dynamics. Age matching is important for evaluating AVJ long-axis function.

Multi-dimensional proprio-proximus machine learning for assessment of myocardial infarction.

This work presents a novel analysis methodology that utilises high-resolution, multi-dimensional information to better classify regions of the left ventricle after myocardial infarction. Specifically, the focus is to determine degree of infarction in regions of the left ventricle based on information extracted from cardiac magnetic resonance imaging. Enhanced classification accuracy is achieved using three mechanisms: Firstly, a plurality of indices/features is used in the pattern classification process, rather than a single index/feature (hence the term "multi-dimensional). Secondly, the method incorporates not only the indices/features of the region in consideration, but also indices/features from the neighbouring regions (hence the term "proprio-proximus"). Thirdly, advanced machine learning techniques are used for both feature selection and pattern classification process to ameliorate the effect of class-imbalance existing in the data. Numerical results from multiple experiments on real data showed that using multiple features improved the ability to distinguish between infarcted and non-infarcted remote segments, and using neighbouring information improved classification performance. The proposed methodology is general and can be adapted for the analysis of biological functions of other human organs.

Automated quantitative assessment of cardiovascular magnetic resonance-derived atrioventricular junction velocities.

The assessment of atrioventricular junction (AVJ) deformation plays an important role in evaluating left ventricular systolic and diastolic function in clinical practice. This study aims to demonstrate the effectiveness and consistency of cardiovascular magnetic resonance (CMR) for quantitative assessment of AVJ velocity compared with tissue Doppler echocardiography (TDE). A group of 145 human subjects comprising 21 healthy volunteers, 8 patients with heart failure, 17 patients with hypertrophic cardiomyopathy, 52 patients with myocardial infarction, and 47 patients with repaired Tetralogy of Fallot were prospectively enrolled and underwent TDE and CMR scan. Six AVJ points were tracked with three CMR views. The peak systolic velocity (Sm1), diastolic velocity during early diastolic filling (Em), and late diastolic velocity during atrial contraction (Am) were extracted and analyzed. All CMR-derived septal and lateral AVJ velocities correlated well with TDE measurements (Sm1: r = 0.736; Em: r = 0.835; Am: r = 0.701; Em/Am: r = 0.691; all p < 0.001) and demonstrated excellent reproducibility [intrastudy: r = 0.921-0.991, intraclass correlation coefficient (ICC): 0.918-0.991; interstudy: r = 0.900-0.970, ICC: 0.887-0.957; all p < 0.001]. The evaluation of three-dimensional AVJ motion incorporating measurements from all views better differentiated normal and diseased states [area under the curve (AUC) = 0.918] and provided further insights into mechanical dyssynchrony diagnosis in HF patients (AUC = 0.987). These findings suggest that the CMR-based method is feasible, accurate, and consistent in quantifying the AVJ deformation, and subsequently in diagnosing systolic and diastolic cardiac dysfunction.

Regional ejection fraction and regional area strain for left ventricular function assessment in male patients after first-time myocardial infarction.

In this work, we present a method to assess left ventricle (LV) regional function from cardiac magnetic resonance (CMR) imaging based on the regional ejection fraction (REF) and regional area strain (RAS). CMR scans were performed for 30 patients after first-time myocardial infarction (MI) and nine age- and sex-matched healthy volunteers. The CMR images were processed to reconstruct three-dimensional LV geometry, and the REF and RAS in a 16-segment model were computed using our proposed methodology. The method of computing the REF was tested and shown to be robust against variation in user input. Furthermore, analysis of data was feasible in all patients and healthy volunteers without any exclusions. The REF correlated well with the RAS in a nonlinear manner (quadratic fit-R(2) = 0.88). In patients after first-time MI, the REF and RAS were significantly reduced across all 16 segments (REF: p < 0.05; RAS: p < 0.01). Moreover, the REF and RAS significantly decreased with the extent of transmural scar obtained from late gadolinium-enhanced CMR images. In addition, we show that the REF and RAS can be used to identify regions with compromised function in the patients with preserved global ejection fraction with reasonable accuracy (more than 78%). These preliminary results confirmed the validity of our approach for accurate analysis of LV regional function. Our approach potentially offers physicians new insights into the local characteristics of the myocardial mechanics after a MI.

Computer-based assessment of ventricular mechanical synchrony from magnetic resonance imaging.

Cardiac resynchronization therapy (CRT) has revolutionized the care of a substantial portion of patients with advanced heart failure (HF). From current guideline (NYHA III or IV heart failure, left ventricular ejection fraction ≤35% and ECG QRS duration ≥ 120 ms), CRT improves clinical status in about 70% of those treated. Ideally, the ability to accurately predict likelihood of response will enhance the quality of treatment. This study aims to develop an automated method to assess left ventricular mechanical synchrony from magnetic resonance imaging (MRI), which has been considered as gold standard cardiac imaging for ventricular structure and function assessment. 26 healthy volunteers (age ranges from 24 years to 73 years) were prospectively recruited and underwent standard MRI scans. MRI images (e.g. 2-chamber, 3-chamber and 4-chamber views) were processed and atrioventricular junction (AVJ) motions were auto-tracked during cardiac cycle. The myocardial velocities Sm1 and Sm2 at systolic phase; Em and Am at early and late mitral filing phase, were derived respectively. The time to these measures (e.g., TSm1, TSm2, TEm and TAm) were determined and ventricular synchrony indices TSm1-SD-6, TSm2-SD-6, TEm-SD-6 and TAm-SD-6 (standard deviations of TSm1, TSm2, TEm and TAm for 6 AVJ points) were assessed and correlated with age. The computational time per dataset is approximately 5 minutes. One-way ANOVA analysis found that there were no significant differences in time to peak velocities in 6 segments. Second, linear regression analysis found that there were no significant correlation between TSm2-SD-6 and TAm-SD-6 with age, and fair positive correlation between TSm1-SD-6 and TEm-SD-6 with age. In this prospective study, noninvasive ventricular synchrony derived from typically acquired MRI images offers a novel method that may enable ventricular mechanical dyssynchrony assessment in heart failure.

Left ventricular diastolic function assessment using time differences between mitral annular velocities and transmitral inflow velocities in patients with heart failure.

BACKGROUND: Evaluation of left ventricular (LV) diastolic function is important in clinical echocardiography. The relationship between mitral annular velocities and transmitral inflow velocities provide additional information about LV filling and diastolic function. This study evaluates the relationships of time intervals between peaks E of mitral inflow velocities and E' of mitral annular velocities, and peaks A and A' in patients with heart failure (HF). METHODS: Eighty patients with HF and 50 age- and gender-matched normal healthy subjects were prospectively recruited and underwent full echocardiograms. The following time intervals were measured: (1) from the onset of R-wave on the ECG to the peak of E-wave on the transmitral flow (TMF) (R-pE); (2) from R to peak of E'-wave on the LV lateral wall of tissue Doppler imaging (TDI) (R-pE'); (3) from onset of P-wave to peak of A-wave on the TMF (P-pA); and (4) from onset of P-wave to peak of A'-wave (P-pA') of TDI. Early-diastolic temporal discordance (EDTD) and late-diastolic temporal discordance (LDTD) were calculated as the difference between the time intervals (R-E) and (R-E'), (P-pA) and (P-p A'). RESULTS: EDTD significantly decreased in patients with HF compared with normal subjects (18.0±54.1ms vs. 28.0±33.5ms, P<0.05). There was also a significant decrease in LDTD in HF patients compared with normal subjects (19.6±23.5ms vs. 34.8±20.6; P<0.05). CONCLUSIONS: EDTD and LDTD decreased in patients with heart failure, and they may be useful tools in identifying abnormal LV relaxation and left atrial contraction for LV diastolic function.

Novel method for atrioventricular motion assessment from three-dimensional cine magnetic resonance imaging.

This study was carried out to (i) track the motion of six atrioventricular junction (AVJ) sites from the two-, three-, and four-chamber cardiovascular magnetic resonance (CMR) views in 27 healthy subjects, (ii) extract four clinically most useful AVJ velocities (i.e., myocardial systolic velocities Sm1 and Sm2, early diastolic velocity Em, and late diastolic velocity Am) for each AVJ site, and (iii) assess the relationship between CMR measurements to age and gender, and set up preliminary normal reference ranges for CMR derived AVJ velocites stratified by age and gender. The data obtained by CMR based method demonstrated that men had significant higher Sm1 (10.5±3.7 cm/s vs. 7.8±2.5 cm/s, P<;0.05) and Am (10.5±4.5 cm/s vs. 7.7±2.6 cm/s, P<;0.05), but comparable Sm2 (6.6±2.2 cm/s vs. 6.9±1.6 cm/s, P>0.05) and Em (11.2±3.3 cm/s vs. 11.5±4.3 cm/s, P>0.05) than women. There was no significant correlation between Sm1, Sm2 and age, while Em and Am strongly or moderately correlated with age. The lateral, posterolateral and posterior AVJ velocities were significant higher than the ones in septal, anteroseptal and anterior locations. Atrioventricular motion and derived velocities are independent of imaging reference frames, and thereby computationally light-weight. They can be derived by post-processing three-dimensional routine CMR images without additional image acquisition. This shall potentially extend routine CMR's capability for left ventricular (LV) systolic and diastolic function assessment.

Assessment of left ventricular preload by cardiac magnetic resonance imaging predicts exercise capacity in adult operated tetralogy of Fallot: a retrospective study.

BACKGROUND: The optimal timing of pulmonary homograft valve replacement (PVR) is uncertain. Cardiopulmonary exercise testing (CPET) and cardiac magnetic resonance (CMR) are often used to guide the clinical decision for PVR in operated tetralogy of Fallot (TOF) patients with significant pulmonary regurgitation (PR). We aim to study the relationship between exercise capacity and CMR in these patients. METHODS: The study is a single-centre retrospective analysis of 36 operated TOF patients [median 21.4 (interquartile range 16.4, 26.4) years post-repair; 30 NYHA I, 6 NYHA II; median age 25.2 (interquartile range 19.5-31.7) years, 29 males] with significant PR on CMR who underwent CPET within 15 [median 2.0 (interquartile range 0.8-7.2)] months from CMR. CPET parameters were compared with 30 age- and sex-matched healthy controls [median age 27.8 (interquartile range 21.0-32.8) years; 24 males]. RESULTS: Peak systolic blood pressure (177 versus 192 mmHg, p = 0.007), Mets (7.3 versus 9.9, p < 0.001), peak oxygen consumption (VO2max) (29.2 versus 34.5 ml/kg/min, p < 0.001) and peak oxygen pulse (11.0 versus 13.7 ml/beat, p = 0.003) were significantly lower in TOF group versus control. Univariate analyses showed negative correlation between PR fraction and anaerobic threshold. There was a positive correlation between indexed left (LV) and right (RV) ventricular end-diastolic volumes, as well as indexed LV and effective RV stroke volumes, on CMR and VO2max and Mets achieved on CPET. These remained significant after adjustment for age and sex. CONCLUSIONS: TOF subjects have near normal exercise capacity but significantly lower Mets, VO2max and peak oygen pulse achieved compared to controls. Increased PR fraction in TOF subjects was associated with lower anaerobic threshold. Higher indexed effective RV stroke volume, a measure of LV preload, was associated with higher VO2max and Mets achieved, and may potentially be used as a predictor of exercise capacity.

Endothelial function and arterial stiffness assessment as early surrogate markers of vascular risk in patients with systemic lupus erythematosus.

Patients with systemic lupus erythematosus (SLE) are at risk of premature atherosclerosis. Conventional prediction risk equations do not adequately predict the cardiovascular risk of these patients because of the complex interaction of traditional and SLE specific risk factors and treatment effects, as well as, the dynamic insult to the vasculature. Non-invasive vascular assessment is able to evaluate the vascular damage accumulated over time. The aim of this review is to examine the role of non-invasive assessment of endothelial function and arterial stiffness as surrogate markers for vascular risk in SLE patients.

International reproducibility of single breathhold T2* MR for cardiac and liver iron assessment among five thalassemia centers.

PURPOSE: To examine the reproducibility of the single breathhold T2* technique from different scanners, after installation of standard methodology in five international centers. MATERIALS AND METHODS: Up to 10 patients from each center were scanned twice locally for local interstudy reproducibility of heart and liver T2*, and then flown to a central MR facility to be rescanned on a reference scanner for intercenter reproducibility. Interobserver reproducibility for all scans was also assessed. RESULTS: Of the 49 patients scanned, the intercenter reproducibility for T2* was 5.9% for the heart and 5.8% for the liver. Local interstudy reproducibility for T2* was 7.4% for the heart and 4.6% for the liver. Interobserver reproducibility for T2* was 5.4% for the heart and 4.4% for the liver. CONCLUSION: These data indicate that T2* MR may be developed into a widespread test for tissue siderosis providing that well-defined and approved imaging and analysis techniques are used.

Multi-center transferability of a breath-hold T2 technique for myocardial iron assessment.

BACKGROUND: Cardiac iron overload is the leading cause of death in thalassemia major and is usually assessed using myocardial T2* measurements. Recently a cardiovascular magnetic resonance (CMR) breath-hold T2 sequence has been developed as a possible alternative. This cardiac T2 technique has good interstudy reproducibility, but its transferability to different centres has not yet been investigated. METHODS AND RESULTS: The breath-hold black blood spin echo T2 sequence was installed and validated on 1.5T Siemens MR scanners at 4 different centres across the world. Using this sequence, 5-10 thalassemia patients from each centre were scanned twice locally within a week for local interstudy reproducibility (n = 34) and all were rescanned within one month at the standardization centre in London (intersite reproducibility). The local interstudy reproducibility (coefficient of variance) and mean difference were 4.4% and -0.06 ms. The intersite reproducibility and mean difference between scanners were 5.2% and -0.07 ms. CONCLUSION: The breath-hold myocardial T2 technique is transferable between Siemens scanners with good intersite and local interstudy reproducibility. This technique may have value in the diagnosis and management of patients with iron overload conditions such as thalassemia.

Regional assessment of left ventricular surface shape from magnetic resonance imaging.

Left ventricular functional abnormalities are postulated to be associated with regional modification of surface curvature. This study describes the computation of the differential properties of the LV surface via an analytic approach using local surface fitting. Quantification was implemented with cine magnetic resonance imaging (MRI), which was used as the source to derive 3D wire-frame models and the related shape descriptors. Based on these shape descriptors, the shape of LV could be represented in both static and dynamic manners. These may have implications for diverse cardiac diseases.