Cardiac magnetic resonance and 64-slice cardiac CT of lipomatous metaplasia of chronic myocardial infarction

A 60-year-old man, who presented two myocardial infarctions 10 years and 6 years ago, was referred for dyspnoea. Clinical examination was unremarkable. Twelve-lead ECG showed abnormal Q waves in D3, VF, V1, and V2. Echocardiography revealed moderately altered global LV function (45% ejection fraction) and wall motion abnormality in the septum and the posterior walls. ECG-gated 1.5T cine-cardiac magnetic resonance (CMR) (steady-state free precession) showed wall thinning and akinesia of the mid septum and severe hypokinesia of the posterior wall. Before contrast injection, these segments exhibited a heterogeneous signal on cine-CMR, with a high signal component in the central part surrounded by a low signal border (Panels A and B). Non-contrast black-blood T1-weighted spin echo images revealed a high signal in the mid septum (Panel C), along with dramatic signal decay after fat saturation (Panel D), indicative of the presence of intramyocardial fat. Delayed-enhanced images acquired 10 min after Gd chelates (0.1 mmol/kg) revealed late hyperenhancement in both infarct territories (Panels E and F). ECG-gated coronary CT showed hypodensity in the mid-septum (Panel G) and in the posterior wall (Panel H) (−50 Hounsfield Units), indicating fatty infiltration. Thus, lipomatous metaplasia may be observed in old myocardial infarctions and may be depicted by CMR and multislice CT. Although comprehensive CMR has a unique value for tissue characterization of the myocardium and fat imaging, MSCT is well suited for detection of fatty infiltration in infarcted myocardium, in addition to its value for non-invasive coronary angiography.