A study on the anatomical morphology of the minor fissure

ABSTRACT

The minor fissure is an important anatomical landmark in the localization of the pulmonary diseases. For the evaluation of the normal feature of the minor fissure, we analyzed the high-resolution computed tomography (CT) scans in 51 normal patients. The purposes of this study are to evaluate the normal appearance of the minor fissure on high-resolution CT scans and to compare it with that on the coventional CT and chest radiographs. We analysed the morphologic feature of the minor fissure on the high-resolution CT scans in 51 normal patients, and compared it with that on the conventional CT scans. On the high-resolution CT scans, we particularly paid attention to the completeness and types according to Berkmen classification. And finally, we compared the types determined by the high-resolution CT scans with those by the plain radiographs. In most patients (n=47), the minor fissure was seen as a hyperattenuating line or hand on the high-resolution CT scans. In contrast, it was mostly seen as a lucent zone on the conventional CT scans (n=44). Of 47 patients having a hyperattenuating line or band on the high resolution CT scans, the minor fissure was considered to be complete in 17 patients (36%), and incomplete in 30 patients (64%), who had defect at medial portion of the minor fissure. The most common type of the minor fissure seen on the high-resolution CT scans was type I variety (n=23), followed by type IIa (n=10) and type II (n=8). We could not determine the type in six patients. The type determined by the high resolution CT scans was highly well correlated with that determined by the plain radiographs (p<0.05). In conclusion, the minor fissure was seen on CT studies as variable appearances and high-resolution CT scans were superior to the conventional CT scans in the evaluation of the minor fissure. The type of the minor fissure determined by the high-resolution CT scans were well correlated with those seen on the radiographs.