CT Evaluation of Normal Interatrial Fat Thickness

Abstract

Purpose This study was performed to determine the normal thickness of fat in the interatrial septum as demonstrated by CT. Method Eighty-seven subjects underwent helical chest CT examination as part of a separate protocol to compare the quantification of coronary artery calcification by CT to coronary angiographic findings, using a slice width of 3 mm, reconstructed every 1.5 mm. The thickness of the interatrial fat in both groups was measured anterior and posterior to the fossa ovalis. The mean and standard deviation were calculated. Results The mean thickness of interatrial fat anterior and posterior to the fossa ovalis was 4.6 (SD = 2.5) and 3.7 (SD = 3.1) mm, respectively. Conclusion The normal range of thickness of the interatrial fat is 0-9.6 mm anterior to and 0-9.9 mm posterior to the fossa (2 SD above the mean).