Value of Cardiac T1-Mapping and ECV Quantification in Duchenne Muscular Dystrophy (DMD): Case Report, Typical Imaging Findings and Review of the Literature

Introduction

Duchenne muscular dystrophy (DMD) is a X-linked recessive disorder affecting approximately 1 of 5000 males. It is the most common inherited muscular dystrophy. Key feature of the disease is a mutation in the gene for dystrophin. Absence, mutation or lack of dystrophin causes cell membrane rupture with consecutive release of creatine kinase. This results in myasthenia and muscular atrophy. Cardiac involvement with progressive global ventricular cardiac dysfunction and dilation can be present.

Autopsy studies showed that cardiac pathologies in DMD contain myocyte hypertrophy but also atrophy, fibrosis and fatty and connective tissue conversions. It is also known that cardiac involvement in DMD is on its way long before symptoms develop. Cardiac disease is the leading cause of death in DMD patients in the second or third decade of life.

Late gadolinium enhancement (LGE) showed promising results in detecting cardiac DMD and in prediction of adverse disease outcome. Silva et al. showed that LGE was present in 7 of 10 DMD patients and identified the lateral wall as the most commonly affected region (Silva et al. Am Coll Cardiol 2007; 49(18): 1874 – 1879), and Florian et al. showed that the transmurality of LGE predicts occurrence of adverse cardiac events (Florian et al. J Cardiovasc Magn Reson 2014; 16: 81). However, LGE imaging underlies several limitations in displaying global myocardial pathologies due to the lack of regional differences in signal intensity. It could also be shown that LGE was more likely to be detected in myocardial segments with at least 15 % collagen fiber components, whereas areas with less advanced fibrosis could not be visualized by LGE (Kim et al. J Am Coll Cardiol 2003; 41: 1568 – 1572).

Parametric imaging techniques, like T1-mapping and extracellular volume fraction quantification (ECV), aim to overcome these problems and exhibited great potential in the early detection of different cardiac diseases. In fact, a recent study demonstrated pathologic native T1 and ECV values in DMD patients with normal heart function and absence of LGE (Soslow et al. J Cardiovasc Magn Reson 2016; 18: 5). Our case report impressively demonstrates typical imaging findings in a young male DMD patient.