BackgroundRecent studies, performed with the use of a commercially available diffusion weighted imaging (DWI) sequence, showed that they are sensitive to the increase of water content in the myocardium and may be used as an alternative to the standard T2-weighted sequences. The aim of this study was to compare two methods of myocardial edema imaging: DWI and T2-TIRM.MethodsThe study included 91 acute and post STEMI patients. We applied a qualitative and quantitative image analysis. The qualitative analysis consisted of evaluation of the quality of blood suppression, presence of artifacts and occurrence of high signal (edema) areas. On the basis of edema detection in AMI and control (post STEMI) group, the sensitivity and specificity of TIRM and DWI were determined. Two contrast to noise ratios (CNR) were calculated: CNR1 - the contrast between edema and healthy myocardium and CNR2 - the contrast between edema and intraventricular blood pool. The area of edema was measured for both TIRM and DWI sequences and compared with the infarct size in LGE images.ResultsEdema occurred more frequently in the DWI sequence. A major difference was observed in the inferior wall, where an edema-high signal was observed in 46% in T2-TIRM, whereas in the DWI sequence in 85%. An analysis of the image quality parameters showed that the use of DWI sequence allows complete blood signal suppression in the left ventricular cavity and reduces the occurrence of motion artifacts. However, it is connected with a higher incidence of magnetic susceptibility artifacts and image distortion. An analysis of the CNRs showed that CNR1 in T2-TIRM sequence depends on the infarct location and has the lowest value for the inferior wall. The area of edema measured on DWI images was significantly larger than in T2-TIRM.ConclusionsDWI is a new technique for edema detection in patients with acute myocardial infarction which may be recommended for the diagnosis of acute injuries, especially in patients with slow-flow artifacts in TIRM images.

Heart failure and arrhythmia are common complications in adults with Ebstein’s anomaly. They may result not only from hemodynamic alterations, but also from myocardial fibrosis. Late gadolinium enhancement (LGE) by CMR enables the evaluation of myocardial fibrosis. The aim of the study was to asses the presence of LGE and its relation to clinical outcome. We studied a group of 37 unoperated adults aged 43.0 ± 14.4 years with Ebstein’s anomaly from the congenital heart disease outpatient clinic. Study protocol included: cardiopulmonary test, assessment of supraventricular arrhythmia (SVA), and CMR with evaluation of cardiac chambers’ morphology and function, and presence of LGE. Variables following normal distribution were shown as mean ± SD if otherwise median (range) was applied. Fibrosis was found in 18 patients (48.6%) and was distributed as follows: 12 patients (32.4%) in the right atrium, 12 (32.4%) in the atrialized right ventricle, and 2 (5.4%) in the functional right ventricle. In patients with fibrosis, the tricuspid regurgitation fraction was bigger (48.3 ± 19.7 vs. 36.1 ± 22.6%, p = 0.048) and SVA was more frequent [12 (66.7%) vs. 6 (31.6%), p = 0.046] when compared to patients without fibrosis. However, exercise capacity did not differ between patients with and without LGE (peak VO2 24.0 ± 4.7 vs. 23.7 ± 4.4, p = 0.87). In adults with Ebstein’s anomaly fibrosis estimated by LGE-CMR was localized in the right atrium and the right ventricle only. Volume overload resulting from tricuspid regurgitation might be a factor conducive to fibrosis. Myocardial fibrosis did not influence exercise capacity. Association between myocardial fibrosis and supraventricular arrhythmia was confirmed.

In conclusion, the slope of the enhancement curve appears to be useful in distinguishing between high- and low-flow vascular malformations. Standardization of MR image evaluation criteria is essential.

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