Magnetic resonance in isolated noncompaction of the ventricular myocardium.

Unlabelled: Non-compaction of the ventricular myocardium (LCVM) is a rare disorder of myocardial morphogenesis usually diagnosed in paediatric age. The diagnosis was echocardiographically made on the basis of a reported spongeous/compacted ratio >2 in one or more segments of the left ventricle during the diastolic period. We aimed to test the diagnostic accuracy of cardiovascular magnetic resonance (CMR) imaging in distinguishing pathological left ventricular non-compaction.

Methods: We collected a consecutive series of 8 patients, 5 males and 3 females, with a mean age of 14.9 years with non-compaction of left ventricular myocardium. All patients were admitted in our divisions of cardiology. In all cases the diagnosis was performed by echocardiography. The diagnosis was obtained when the spongeous/compacted ratio was >2 in one or more segments of left ventricle, evaluated in systolic and diastolic period. In the end we completed the diagnosis by scanning with a Signa HD 1.5 T (GE, Milwaukee, USA) the same 8 patients affected by non compaction of ventricular myocardium. In all patients cardiac-gated T1 and T2 black-blood FSE images in short axis and in four-chamber horizontal long axis were obtained. Breath hold cine MR sequences (FIESTA) were performed, covering the whole left ventricle in short-axis plane and in four-chamber view. A segmented inversion-recovery fast gradient echo sequence (IR-FGE) was performed in the short-axis plane of the LV and in four-chamber-view after Gadolinium injection in 8 patients affected by non compaction of left ventricle. At the end of examination the spongeous/compacted ratio >2 was calculated in all involved segments of the left ventricle in diastole.

Results: In all cases we demonstrated by echocardiography an involvement of the ventricular apex. In 3 cases the structural alterations involved also lateral wall of left ventricle. Magnetic resonance evaluation showed that involvement demonstrated by the echocardiogram was the same: ventricular apex involved in every patient, lateral wall in 3 and all segments in 2. However the spongeous/compacted ratio was >>2 in all patients, with a mean value of 3,1.

Conclusions: Although our data refer to a small population of patients and need further confirmation, they suggest that it seems reasonable increase the cut-off for spongeous/compacted ratio from a value of 2 to 2.5 for non-compaction diagnosis when high-resolution magnetic resonance is used.