Evaluation of fluid collection in the pericardial sinuses and recesses - Noncontrast-enhanced electron beam tomography

RATIONALE AND OBJECTIVES. TO evaluate the attenuation, size, and volume of the pericardial sinuses and recesses by using electrocardiographically trig gered, noncontrast-enhanced electron beam tomography (EBT) and to consider its relation with sex, age, and heart volume. METHODS. Findings in 213 consecutive patients without known pericardial dis ease were studied. The patients underwent EBT scanning of the heart to eval uate coronary artery calcification. Incremental electrocardiographically tr iggered noncontrast images were obtained with a 100-ms exposure time and a 3-mm slice thickness. The appearance, density, and volume of the pericardia l sinuses and recesses were calculated. RESULTS. Among the 213 patients, 97.2% had at least one of the sinuses or r ecesses visible on EBT, The sinuses or recesses were seen with the followin g frequency: transverse sinus (93.9%), oblique sinus (71.8%), and superior aortic recess (51.2%). The mean attenuation and volume were 9.9 +/- 7.3 Hou nsfield units (HU), 12.6 +/- 8.1 HU, and 12.6 +/- 8.7 HU, and 1.9 +/- 1.3 m L, 1.3 +/- 1.0 mL, and 0.8 +/- 0.8 mL, respectively, The total volume of th e pericardial sinuses (3.3 +/- 2.2 mt) had no significant relation with the total heart volume. CONCLUSIONS. Pericardial sinuses and recesses were frequently and well depi cted on noncontrast EBT images. In patients without obvious pericardial eff usion, physiological fluid collections were observed in the transverse and oblique sinuses or other recesses. Location, attenuation, and volume were h elpful in the differentiation of normal pericardial sinuses from pericardia l effusions and mediastinal lymph nodes.