[Detection of parietal lesions using magnetic resonance imaging in arrhythmogenic dysplasia of the right ventricle]. / Mise en évidence par l'IRM des lésions pariétales au cours de dysplasies arythmogènes du ventricule droit.

Seven patients with arrhythmogenic right ventricular dysplasia were explored by magnetic resonance imaging (MRI), using the spin-echo technique (TR = the patient's own RR cycle; TE = 28 ms, 56 ms, 84 ms) with multiple, contiguous, 7 to 10 mm thick sections performed in two planes: axial plus sagittal or frontal planes. In 5 out of 7 patients, MRI showed dysplastic lesions in the right ventricular wall presenting typically as fat-like high signals contrasting with the normal myocardium. In 2 patients, no lesion was clearly visualized. The parietal lesions were located in the anterior wall of the right ventricle and conus arteriosus in 5 cases and in the lower wall of the right ventricle in one patient who had two dysplastic areas. In 3 patients the lesions extended up to the tip of the interventricular septum and of the left ventricle. In the 2 patients whose lesions were most extensive, their predominance in the subepicardial region and the concordance between the sites of abnormalities at MRI and angiography were clearly observed. Thus, despite its present technical limitations MRI seems to be one of the first techniques capable of visualizing the parietal lesions in patients with arrhythmogenic right ventricular dysplasia.