Magnetic resonance imaging of microvascular leakage induced by myocardial contrast echocardiography in rats

Cardiac magnetic resonance visualizes acute and chronic myocardial injuries in myocarditis

Our objective was to evaluate the ability of CMR to visualize myocardial injuries over the course of myocarditis. We studied 42 patients (39 males, 3 females; age 37 ± 14 years) with myocarditis during the acute phase and after 12 ± 9 months. CMR included function analyses, T2-weighted imaging (T2 ratio), T1-weighted imaging before and after i.v. gadolinium injection (global relative enhancement; gRE), and late gadolinium enhancement (LGE). In the acute phase, the T2 ratio was elevated in 57%, gRE in 31%, and LGE was present in 64% of the patients. In 32 patients (76%) were any two (or more) out of three sequences abnormal. At follow-up, there was an increase in ejection fraction (57.4 ± 11.9% vs. 61.4 ± 7.6; P < 0.05) while both T2 ratio (2.04 ± 0.32 vs. 1.70 ± 0.28; P < 0.001) and gRE (4.07 ± 1.63 vs. 3.11 ± 1.22; P < 0.05) significantly decreased. The LGE persisted in 10 patients. Dilated cardiomyopathy was present in 3 patients and 4 patients received a defibrillator or a pacemaker. A comprehensive CMR approach is a useful tool to visualize myocardial tissue injuries over the course of myocarditis. CMR may help to differentiate acute from healed myocarditis, and add information for the differential diagnoses.

Myocardial tissue characterization in systemic lupus erythematosus: value of a comprehensive cardiovascular magnetic resonance approach

Systemic lupus erythematosus (SLE) is a multi-organ inflammatory disorder mainly affecting women and is associated with high cardiovascular morbidity and mortality. We tested the utility of a comprehensive cardiovascular magnetic resonance approach to assess myocardial involvement and to determine its relation to disease activity in SLE patients. We studied 20 SLE patients (19 females, 35 ± 10 years) and 13 healthy volunteers (nine females, 28 ± 11 years). Classification followed the criteria of the American College of Rheumatology and assessment of SLE activity was based on the European Consensus Lupus Activity Measurement index. Cardiovascular magnetic resonance (CMR) was performed on a 1.5T scanner and included the following sequences: steady-state free precession, T2-weighted, early and late T1-weighted after gadolinium-DTPA injection. Ejection fraction was not significantly different between groups (controls: 63 ± 6, inactive SLE: 67 ± 7, active SLE 64 ± 8; P = 0.003 for all groups). In contrast, relative T2 ratio (myocardium to skeletal muscle) was significantly higher in active SLE than in the other groups (controls: 1.7 ± 0.3, inactive: 1.8 ± 0.2, active: 2.1 ± 0.2; P = 0.003). Similarly, early enhancement ratio was significantly higher in active SLE (controls: 2.4 ± 1.4, inactive: 2.8 ± 1.1, active: 4.5 ± 2.0, P = 0.39). Both relative T2 and early enhancement ratios significantly correlated with disease activity. Intramural foci of late enhancement were observed in three of eight patients (all with active SLE). Of the five patients with no late enhancement, only one had active disease. An imaging approach combining T2-weighted, early and late enhancement imaging is a useful tool to assess possible myocardial involvement in SLE. CMR parameters of global myocardial involvement correlate well with disease activity, but not with usual clinical signs as summarized in a cardiac score.