Inferior Accessory Fissure on Multi-Detector CT Image

Abstract

Purpose To assess the frequency and morphological characteristics of inferior accessory fissures (IAFs) of the lung by multi-detector CT (MDCT) images, and describe their configurations under pathologic conditions.

Materials and Methods We analyzed chest CT scans of 1004 patients and assessed the frequency, completeness, location, shape and length of IAFs on MDCT source image with multiplanar reformatted images. We described pathologic conditions associated with IAFs.

Results The frequency of IAFs was 13.3%: 123 were found in the right lung, 13 in the left and 3 bilaterally. All IAFs of the right lung were incomplete fissures; three of complete fissures only on the left. IAFs were most common in paramedian location (65.9%). Linear fissures were more common than curved ones. The average length was 22.3 mm. The curved fissures were longer than linear fissures. The IAFs in lateral locations were longer than ones at other locations. There were eight cases associated with pathologic conditions.

Conclusion On MDCT imaging, the frequency of IAFs is 13.3%. IAFs are more frequent in the right lung and paramedian location and are mostly incomplete and linear. Understanding morphologic features of fissures should help us understand topographic features of basal lung, which has pathologic condition associated with IAF.