Diagnosing leftventricular noncompaction by cardiac MRI and its differential diagnosis on leftventricular hypertrabeculation

：Objective To define thediagnostic criteria of cardiovascular magnetic resonance imaging in distinguishingisolated left ventricular noncompaction (LVNC) from lesser degrees of hypertrabeculation.Methods Twenty-five patients with LVNC, 39 with dilated cardiomyopathy ( DCM), 16 withaortic stenosis(AS), 15 with aortic regurgitation(AR) , 19 with hypertension (HT) and 22normal subjects were enrolled in this study. Cardiac magnetic resonance imaging wasperformed to evaluate the left chamber diameter, functional parameters and noncompactionor hypertrabeculation of the left ventricle in diastole with one-way ANOVA. The leftventricle was divided into 17 segments for localizing all involved segments in thispresent study. Results The LVNC patients had the commonest myocardial segments involved(10±2)in all subjects. Each patient with LVNC was unexceptionally associated with apicalnoncompaction (17th segment) , which was seldom found in the other subjects. The lateralwalls including 16th, 12th and 11th segments were the most vulnerable segments in allsubjects, but nobody was found to involve the basal and mid septum including 2nd, 3rd, 8thand 9th segments. The end-diastolic NC/C (noncompaction/compaction) ratio was, on average,the greatest in patients with LVNC (3.3±0.6), compared with all other subjects(AS:1.0 ±0.3,AR:1.0 ±0.3,HT:0.8 ±0.1,healthy volunteers:0.9 ±0. 2) (F = 169. 62,P 2.5 as a valuable parameter to distinguish LVNC from DCM.with values for sensitivityof 96.O%(24/25)and specificity of 94.9%(37/39),respectively.The mean number of NC/Cratio>2.5 segments in the LVNC patients was 4.0 ±2.0.while 8 of 39 patients with DCMhad only one segment of NC/C ratio >2.5.Conclusions MRI is all exceUent imagingmodality to diagnose LVNC and distinguish LIVNC from hypertrabeeulation.The criteria ofLVNC is the NC/C ratio>2.5 in two or more than two segments of free ventricular wallsassociated with the left ventrieular apex involved.