Delineation of the interlobar fissures on multiplanar reconstruction (MPR) images is useful to assess masses at the fissures for invasion into adjacent lobes. We performed this study to determine the appropriate MDCT protocol to visualize the interlobar fissures on sagittal MPR images. For the phantom studies, radiographic film was used to replicate the interlobar fissures. For the clinical studies, we obtained MDCT scans of 130 patients with normal interlobar fissures. Visualization of the interlobar fissures on sagittal MPR was assessed using the following scanning parameters: scan collimations of 0.5, 1, 2, and 3 mm with helical pitches of 1 and 1.5 for the phantom studies; and scan collimations of 0.5, 1, 2, and 3 mm with a helical pitch of 1.5 and a scan collimation of 2 mm with a helical pitch of 1 for the clinical studies. To visualize fissures as a sharp line, a 0.5- or 1-mm collimation was required for the major fissure and 0.5 mm for the minor fissure in the phantom studies. In the clinical studies, 0.5-mm-collimation MPR images depicted interlobar fissures as a sharp line in all cases. Fissures on MPR images using 1-, 2-, and 3-mm collimations appeared as a sharp line in 77.5-95.0%, 0-43.3%, and 0% of cases, respectively. Volume data obtained using a 1-mm collimation are required to visualize all the interlobar fissures as a sharp line on sagittal MPR images except the minor fissure and superior portion of the right major fissure, for which a 0.5-mm collimation is required.
