[Multiplane postmortem cerebral computed angiotomography--Part II. Normal anatomy of cerebral vessels on the modified coronal, Towne and semisagittal planes].

In order to obtain a detailed knowledge of the cerebral vasculature on computed tomographic (CT) images, multiplane CT scannings on the axial, coronal, Towne and sagittal planes are required. Previous reports have concerned only the axial CT images of the cerebral vasculature, and no mention has been made about the vasculature on the coronal, Towne or sagittal images. This paper concerns the normal anatomy of the cerebral vessels on the modified coronal, Towne (half-axial) and semisagittal CT planes using 9 fresh cadavers. They received postmortem injection of contrast agents and were scanned by GE-CT/T 8800 as mentioned in Part I. Scanning planes were the modified 50-60 degrees coronal, Towne (40-45 degrees off the canthomeatal line), and the semisagittal (45 degrees toward the sagittal plane). The main vascular structures visualized on the modified coronal CT plane resembled the antero-posterior view of the carotid angiogram, and they were as follows: internal carotid arteries (supra-clinoid portion), posterior communicating arteries, anterior choroidal arteries, anterior cerebral arteries (horizontal and ascending portions, pericallosal and callosomarginal arteries and other cortical branches), middle cerebral arteries (horizontal, insular, opercular and terminal portions with identification of the angiographic Sylvian point), lenticulostriate arteries, posterior cerebral arteries, basal vein of Rosenthal (BVR), internal cerebral veins (ICV), subependymal veins which drain into BVR and ICV, choroid veins, vein of Galen, and venous sinuses. As for the demonstration of the lenticulostriate arteries or the Moyamoya vessels in clinical cases, the modified coronal plane is preferred to the axial one. On Towne plane, the vertebro-basilar arteries and the ascending portion of anterior cerebral artery were demonstrated as linear densities, which were demonstrated as spotty densities on the axial plane. On the semisagittal plane, the median or paramedian vasculatures of the main cerebral arteries and deep cerebral veins, were well demonstrated like a lateral view of carotid angiogram. Biplane or multiplane cerebral computed angiotomography will increase in clinical diagnostic value for understanding the anatomical relationship between the cerebral vessels and other intracranial lesions, and also will be applied to the screening of small vascular lesions themselves, e.g., asymptomatic aneurysms, vascular occlusions, arteriovenous malformations and Moyamoya diseases.