Evaluation of Pulmonary Lobe Variations Using Multidetector Row Computed Tomography

Purpose: To examine incomplete pulmonary lobes and their variations using multiplanar reformation (MPR) techniques of isotropic voxel data produced by multidetector row computed tomography (CT). Materials and Methods: The subjects were 1000 patients who underwent thoracic CT. All examinations were performed using 16-row multidetector CT with a slice thickness of 1 mm. Interlobar fissures were observed by scrolling MPR techniques for various directions. Results: Incomplete interlobar fissure was observed in 42.2% of subjects. Incomplete interlobar fissures between the right upper and middle lobes were observed in 20.4% of subjects, right major fissure was recorded in 17.4%, and left major fissure in 19.2%. Excessive fissure formation was observed in 8% of subjects (4 lobes on the right in 5.7%, 3 lobes on the left in 2.3%). Approximately half of the subjects with incomplete interlobar fissures had coexisting abnormalities in other lobes, whereas approximately one third of those with excessive fissures had coexisting abnormalities in other lobes. Conclusions: The incidence of incomplete lobulation observed by multidetector CT in this study is remarkably lower than that reported in previous CT studies but is comparable with that reported from autopsy results. It is important to perform multidirectional observation using MPR.