Figure 20a. Chronic organized pericardial hematoma in a 39-year-old man who presented with syncope and chest discomfort and had a history of blunt chest trauma 8 years prior. (a) Axial ECG-gated T1-weighted SE image shows a well-circumscribed mass (M) with intermediate signal intensity in the left atrioventricular groove; the mass compresses the left atrium and ventricle. (b) Axial cine GRE image shows a mass (M) with low-signal-intensity foci and a low-signal-intensity rim (arrows), which are indicative of central and peripheral calcifications. These findings were confirmed at subsequent surgery.