耳科学における画像診断の進歩
CT・MRIを中心に
2002 年 12 巻 2 号 p. 73-79
詳細
2002 年 12 巻 2 号 p. 73-79
CT is the imaging investigation of choice for many lesions of the temporal bone. Recently advanced multislice CT (MSCT) with thin slice collimation (0.5mm) can provide “isotropic” voxel data, which can almost completely eliminate partial volume averaging errors related to the slice width. By using isotropic data, multiplanar reconstruction (MPR) images of any direction can be generated with spatial resolution equivalent to that of axial images. Direct coronal images, which are mandatory in the evaluation of many lesions in the temporal bone, can be replaced by MPR images. Also three-dimensional (3D) images can be obtained with high quality. MR imaging, which provides better tissue contrast than CT, is useful for characterization of “soft tissue lesions” MRI is the imaging modality of first choice for lesions in the inner ear and its central connection. In addition to Ti-, T2-weighted and contrast enhanced images, 3D heavily T2-weighted images (MR hydrography), such as CISS, FSE and FASE, are useful to estimate the inner ear, internal auditory canal, CP angle cistern, cranial nerves, and so on.
