Pitfalls in Oncologic Imaging: Pericardial Recesses Mimicking Adenopathy

Abstract

Introduction The pericardium is a thin, avascular sac that envelops the heart. It is made up of an outer fibrosa (the fibrous pericardium) and a double-layered inner serosa (the serous pericardium). The serosa forms a complete sac (the pericardial cavity) which is filled with up to 50 mL of plasmatic ultrafiltrate and is separated from the heart by loose epicardial connective tissue and a single layer of mesothelial cells. The pericardial cavity contains 2major pericardial sinuses, the transverse and oblique sinuses, which, in turn, are composed of different recesses (Fig. 1). Advances in multidetector computed tomography (MDCT) technology have improved detection of pericardial recesses. Ozmen et al have shown that visualization rates of pericardial recesses are higher with 4-, 16-, and 64-slice MDCT than with 2-slice MDCT. Additionally, thin-section computed tomography (CT) has improved the detection of pericardial recesses and sinuses. Kodama et al assessed the prevalence of pericardial sinuses and recesses on thin section (2.5 or 3 mm) and thick section (5 or 7 mm) CT scans. Thinsection CT improved the depiction rate of every pericardial sinus and recess: 44.7% comparedwith 30.4% for the superior aortic recess, 16.7% comparedwith 3.4% for the inferior aortic recess, 36.8% compared with 12.5% for the left pulmonic recess, 29.7% compared with 7.9% for the right pulmonic recess, 28.7% compared with 7.7% for the oblique sinus, 16.8% compared with 2.7% for the postcaval recess, 19.8% comparedwith 2.5% for the left pulmonary venous recess, and 10.8% compared with 4.7% for the right pulmonary venous recess. Similarly, Basile et al identified the high-riding