Comparing Thin-Section and Thick-Section CT of Pericardial Sinuses and Recesses

Abstract

OBJECTIVE. The aim of this study was to assess the prevalence and appearance of the pericardial sinuses and recesses on thin-section (2.5- or 3-mm) CT scans compared with thick-section (5- or 7-mm) CT scans. MATERIALS AND METHODS. Nine hundred forty-one consecutive contrast-enhanced chest CT scans were retrospectively evaluated. Three hundred sixty-five patients underwent thin-section CT, and 576 patients underwent thick-section CT. The prevalence and appearance of every pericardial recess were determined. RESULTS. Large recesses such as the superior aortic recess were depicted in 12.5–30.4% of patients using thick-section CT, whereas smaller recesses such as the postcaval recess were depicted in fewer than 5% of patients. With thin-section CT, the depiction rates increased significantly compared with thick-section CT (p < 0.01). Large recesses were depicted in 28.7–44.7% of patients, and smaller recesses were recognized in 10.8–19.8% of patients. Generally, most recesses were linear if they were small and became band-shaped as the fluid increased. However, the recesses were often visualized as crescent, triangle, spindle, ovoid, hemisphere, or irregular shapes. CONCLUSION. Pericardial sinuses and recesses are more frequently and better depicted on thin-section CT scans. Knowledge of their locations and shapes is helpful for distinguishing pericardial fluid from abnormal findings such as lymphadenopathy and cystic lesions.