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 triggered, 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 disease were studied. The patients underwent EBT scanning of the heart to evaluate coronary artery calcification. Incremental electrocardiographically triggered noncontrast images were obtained with a 100-ms exposure time and a 3-mm slice thickness. The appearance, density, and volume of the pericardial sinuses and recesses were calculated.

RESULTS

Among the 213 patients, 97.2% had at least one of the sinuses or recesses visible on EBT. The sinuses or recesses were seen with the following 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 Hounsfield units (HU), 12.6 +/- 8.1 HU, and 12.6 +/- 8.7 HU, and 1.9 +/- 1.3 mL, 1.3 +/- 1.0 mL, and 0.8 +/- 0.8 mL, respectively. The total volume of the pericardial sinuses (3.3 +/- 2.2 mL) had no significant relation with the total heart volume.

CONCLUSIONS

Pericardial sinuses and recesses were frequently and well depicted on noncontrast EBT images. In patients without obvious pericardial effusion, physiological fluid collections were observed in the transverse and oblique sinuses or other recesses. Location, attenuation, and volume were helpful in the differentiation of normal pericardial sinuses from pericardial effusions and mediastinal lymph nodes.