Isolated left ventricular myocardium non-compaction: MR imaging findings from three cases

The purpose of this study is to report three cases of left ventricular myocardium non-compaction (LVNC), with emphasis on the MRI findings. From May 2006 to February 2007, three patients -- 2 females (6 years and 42 years of age) and 1 male (18 years of age) -- presented to our radiology department, two of them with fatigue, shortness of breath and episodes of syncope and arrhythmia, for further investigation by cardiac MRI because an apparent asymmetrical pattern of hypertrophy of the left ventricular myocardium was suspected by transthoracic echocardiography. The 18-year-old patient was only experiencing arrhythmia, and arrhythmogenic right ventricular dysplasia was suspected. The images (produced by a 1.5T MRI system) were interpreted by two experienced radiologists and post-processed with Argus software (Siemens, Germany) for ejection fraction calculation. In all three patients, MRI aided in the correct identification of prominent ventricular myocardial trabeculations and deep intertrabecular recesses communicating with the ventricular cavity, as well as areas of hypokinesia with depressed systolic function, and showed the absence of myocardial delayed enhancement and other structural heart defects. In conclusion, cardiac MRI was useful for correctly identifying this rare congenital heart disorder and appears to increase diagnostic accuracy. Although considered a rare anomaly, radiologists should be capable of recognizing LVNC, as current non-invasive imaging methods have increased the frequency of this diagnosis and timely detection is vital in considering early-stage transplantation.