Late Gadolinium Enhancement of the right ventricular myocardium: Is it really different from the left ?

We present 7 cases as well as computer simulations to describe the nature of these artifacts and explain how they can create the impression of different inversion times for the right and left ventricle. At inversion times that are shorter than ideal for the myocardium a black rim can be seen at the border of the myocardium with blood on the inside and with fat on the outside. This is most likely a partial volume effect. The thin myocardium of the right ventricle is sandwiched between these black rims and, at a low spatial resolution, is no longer visible. In this case, the adjacent black rims may then be misinterpreted as myocardium. While black rims also occur on the left side, the myocardium is thicker and remains discernable as a separate layer. As a consequence, the optimal inversion time for the right ventricle only appears different from that for the left. In fact, in the presence of hypertrophy of the right ventricle or during systolic wall thickening we did not find a difference in inversion times between the left and right ventricle. We conclude that sufficient spatial resolution is important for adequate late gadolinium enhancement of the right ventricle.Late Gadolinium Enhancement (LGE) sequences have become a routine part of cardiovascular magnetic resonance (CMR) for ischemic heart disease, myocarditis and the cardiomyopathies [1-6]. In pediatric cardiology, LGE is used most often to look for fibrosis in suspected arrhythmogenic right ventricular dysplasia (ARVD)[7,8]. In this condition, compared to the findings in acute myocardial infarction, LGE is less pronounced and more diffuse. In the right ventricle (RV), even transmural fibrosis may only be < 2 mm thick[9]. Moreover, LGE is rare in pediatric ARVD patients and, if present, subtle[10]. For these reasons, an optimal contrast-to-noise ratio between normal and fibrotic myocardium is even more important than for the LV myocardium. In order to maximize the contrast between healthy and enhanced necrotic