Background LGE by CMR is a predictor of adverse cardiovascular outcomes in non-ischemic cardiomyopathy (NICM) patients. However, these findings are limited by single center studies, small sample sizes, and low event rates. We performed a meta-analysis to evaluate the prognostic role of late-gadolinium enhancement by cardiac magnetic resonance (LGE-CMR) imaging in NICM patients. Methods and Results PubMed, Cochrane CENTRAL and EMBASE were searched for studies looking at the prognostic value of LGE-CMR in NICM patients. The primary end-points included all-cause mortality, heart failure hospitalization (HFH), and a composite end point of sudden cardiac death (SCD) or aborted SCD. Pooling of odds ratios (OR) was performed using a random-effect model and annualized event rates (AER) were assessed. Data was included from 9 studies with a total of 1,488 patients and a mean follow-up of 30 months. Patients had a mean age of 52 years, 67% were male and the average LVEF was 37% on CMR. LGE was present in 38% of patients. Patients with LGE had increased overall mortality (OR 3.27, p<0.00001), HFH (OR 2.91, p=0.02), and SCD/aborted SCD (OR 5.32, p<0.00001) when compared with those without LGE. The AERs for mortality were 4.7% for LGE+ subjects vs. 1.7% for LGE- subjects (p=0.01), 5.03% vs. 1.8% for HFH (p=0.002), and 6.0% vs. 1.2% for SCD/aborted SCD (p<0.001). Conclusions LGE in NICM patients is associated with increased risk of all-cause mortality, HFH, and SCD. Detection of LGE by CMR has excellent prognostic characteristics and may help guide risk stratification and management in NICM patients.

Objectives To assess the relationship between extracellular volume (ECV), native T1, and systolic strain in hypertensive patients with left ventricular hypertrophy (HTN LVH), hypertensive patients without LVH (HTN Non-LVH) and normotensive controls. Background Diffuse myocardial fibrosis in HTN LVH patients, as reflected by increased ECV and native T1, may be an underlying mechanism contributing to increased cardiovascular risk when compared to HTN Non-LVH subjects and controls. Furthermore increased diffuse fibrosis in HTN LVH subjects may be associated with reduced peak systolic and early diastolic strain rate when compared to the other two groups. Methods T1 mapping was performed in 20 HTN LVH (55±11 years), 23 HTN Non-LVH (61±12) and 22 control (54±7) subjects on a Siemens 1.5T Avanto using a previously validated MOLLI pulse sequence. T1 was measured pre-contrast and 10, 15 and 20 minutes following injection of 0.15 mmol/kg Gd-DTPA, and the mean ECV and native T1 were determined for each subject. Measurement of circumferential strain parameters were performed using cine displacement encoding with stimulated echoes (DENSE). Results HTN LVH subjects had higher native T1 when compared to controls (p < 0.05). HTN LVH subjects had higher ECV when compared to HTN Non-LVH subjects and controls (p < 0.05). Peak systolic circumferential strain and early diastolic strain rate were reduced in HTN LVH subjects when compared to HTN Non-LVH subjects and controls (p < 0.05). Increased levels of ECV and Native T1 were associated with reduced peak systolic and early diastolic circumferential strain rate across all subjects. Conclusions HTN LVH patients had higher ECV, longer native T1 and associated reduction in peak systolic circumferential strain and early diastolic strain rate when compared to HTN Non-LVH and control subjects. Measurement of ECV and native T1 provide a non-invasive assessment of diffuse fibrosis in hypertensive heart disease.

Purpose To develop and validate modified Look‐Locker (MOLLI) protocols to generate myocardial T1 maps within clinically acceptable breath‐hold durations and to compare partition coefficients (λ) of gadolinium (Gd)‐DTPA determined from either bolus injection (BI) or continuous infusion (CI) techniques. Materials and Methods T1 mapping was performed in phantoms and in 10 volunteers on a 1.5T scanner using the standard (3‐3‐5) MOLLI technique and two MOLLI schemes with shorter breath‐hold durations. Imaging was performed precontrast and every 5 minutes following a bolus of 0.1 mmol/kg Gd‐DTPA and a 15‐minute delayed continuous infusion of 0.001 mmol/kg Gd‐DTPA until equilibrium T1 in the myocardium was achieved to enable direct comparison of T1 relaxation times between techniques and λ's between the BI and CI methods. Results There was good agreement of T1 values between the 3‐3‐5 standard MOLLI protocol and the modified 3‐5 MOLLI protocol in both phantom studies over a range of heart rates and in human subjects. Both MOLLI protocols produced similar measurements of λ using both the BI and CI methods. Conclusion A reduced breath‐hold MOLLI T1 mapping protocol combined with the BI method can accurately characterize T1 and λ in clinically applicable breath‐hold durations without requiring a long equilibrium phase infusion. J. Magn. Reson. Imaging 2013;38:217–224. © 2012 Wiley Periodicals, Inc.

Positron emission tomography-magnetic resonance imaging (PET/MRI) is emerging as a novel diagnostic modality with exciting potential for a role in multiple cardiovascular applications. The combination of the high sensitivity of PET tracers with the excellent spatial resolution and tissue characterization of cardiac MRI will provide complementary information in a variety of cardiac pathologies. While initial efforts have focused on the combination of MRI and PET for assessment of coronary artery disease, cardiomyopathy, viability, and inflammation, this new technology holds enormous potential for molecular cardiovascular imaging. This article will review the development of PET/MRI, review the current research, and discuss potential future applications.