Topographic analysis of the inferior parietal lobule in high-resolution 3D MR imaging.

BACKGROUND AND PURPOSE Recent functional MR imaging studies have revealed that the inferior parietal lobule (IPL) supports numerous functions; however, the precise organization of the IPL remains unclear. It has been previously reported that the individual components of the IPL show variable morphologic features; thus, any investigations of IPL function must take into account the variable topography of the IPL. However, it is difficult to understand the topography of the IPL only in transaxial and/or sagittal MR images. We generated volume rendering (VR) images of the brain from high-resolution 3D MR imaging data and analyzed the topography of the IPL. MATERIALS AND METHODS Forty healthy volunteers were examined with 1.5T MR imaging, and VR images were generated. Sulcal continuity, sulcal connections, and the gyral pattern of the IPL were investigated. RESULTS The main sulci and gyri were able to be identified excellently on VR images of all volunteers. One long, continuous postcentral sulcus (postCS) was seen in 47.5% and 40% in the right and left hemisphere, respectively. The frequency with which the postCS connected with the anterior end of the IPS was 72.5% and 75% in the right and left, respectively. The gyral pattern of the IPL showed variable morphology. CONCLUSIONS VR images can depict the sulcal continuity and connections of the IPL accurately. VR imaging is a very useful noninvasive technique to observe the topography of the IPL and should contribute to the investigation of functional localization.