Imaging the pericardium: appearances on ECG-gated 64-detector row cardiac computed tomography

Abstract

ABSTRACT. Multidetector row computed tomography (MDCT) with its high spatial and temporal resolution has now become an established and complementary method for cardiac imaging. It can now be used reliably to exclude significant coronary artery disease and delineate complex coronary artery anomalies, and has become a valuable problem-solving tool. Our experience with MDCT imaging suggests that it is clinically useful for imaging the pericardium. It is important to be aware of the normal anatomy of the pericardium and not mistake normal variations for pathology. The pericardial recesses are visible in up to 44% of non-electrocardiogram (ECG)-gated MDCT images. Abnormalities of the pericardium can now be identified with increasing certainty on 64-detector row CT; they may be the key to diagnosis and therefore must not be overlooked. This educational review of the pericardium will cover different imaging techniques, with a significant emphasis on MDCT. We have a large research and clinical experience of ECG-gated cardiac CT and will demonstrate examples of pericardial recesses, their variations and a wide variety of pericardial abnormalities and systemic conditions affecting the pericardium. We give a brief relevant background of the conditions and reinforce the key imaging features. We aim to provide a pictorial demonstration of the wide variety of abnormalities of the pericardium and the pitfalls in the diagnosis of pericardial disease.

Pericardial Masses, Cysts and Diverticula: A Comprehensive Review Using Multimodality Imaging

“…28 Teratomas often have calcium or fat within a pericardial mass on cCT. 4 Fibromas are poorly vascularized and have no or irregular enhancement with iodinated contrast. 4 While lipomas, teratomas and fibromas have typical appearances and may be diagnosed by imaging alone, there is significant overlap with findings of other tumors.…”

“…4 Fibromas are poorly vascularized and have no or irregular enhancement with iodinated contrast. 4 While lipomas, teratomas and fibromas have typical appearances and may be diagnosed by imaging alone, there is significant overlap with findings of other tumors. Hemangiomas appear heterogenous and enhance with iodinated contrast administration.…”

“…3 On cardiac computed tomography (cCT) the pericardium is visualized as a bright, linear structure around the heart in contrast to surrounding fat with an average thickness of 1.3-2.5 mm. 3,4 By Cardiac Magnetic Resonance Imaging (cMRI) the average pericardial thickness is 1.2 mm in diastole and 1.7 mm in systole with variable visualization depending on the image plane. 5 Pericardial fluid has low-signal intensity on T 1 -weighted sequences; however, with fat suppression the background signal becomes suppressed and pericardial fluid develops a high signal intensity.…”

“…[59][60][61] Chronic organized hematomas often have a dark peripheral rim with low signal intensity internally which may represent fibrosis, hemosiderin deposition or calcification. 4,51,62 Hematomas do not enhance with gadolinium contrast administration which allows them to be distinguished from pseudoaneurysms and neoplasms. 10,56 Pseudoaneurysms also demonstrate internal flow with velocity-encoded cine MR imaging as opposed to hematomas.…”

“End-Stage” Constrictive Pericarditis—A Case Report

“…A thickened pericardium (>4 mm) on its own does not indicate constrictive pericarditis [26]. In 20% of cases of constrictive pericarditis, imaging methods show a pericardium of normal thickness and in such cases, the constrictive process may be caused by epicardial rather than pericardial constriction [27].…”