脳動脈りゅう，　脳血管狭窄性病変の診断における３Ｄ‐ＣＴ　ａｎｇｉｏｇｒａｐｈｙの有用性の検討

In this report, we describe our initial experience with three-dimensional CT angiography (3D-CTA) in the evaluation of intracerebral lesions. The purpose of the study was to assess the detection of lesions of the intracranial vasculature by 3D-CTA and to compare the results obtained with those of both digital subtraction angiography (DSA) and magnetic resonance angiography (MRA). Six patients including 4 with intracranial aneurysms and 2 with stenosis of the vertebral artery and basilar artery were investigated with 3D-CTA and DSA, and also underwent MRA. 3D-CTA is a rapid non-invasive method for visualizing the intracranial vasculature. In this study, aneurysms measuring 3 mm or larger were demonstrated by 3D-CTA as well as MRA. All of the aneurysms observed with both 3D-CTA and MRA were seen equally well by both techniques. 3D-CTA has several properties that afford it unadvantage over MRA. 3D-CTA acquistion takes only 20 sec to perform, so that lesions can be imaged without motion artifacts. The 3D-CTA image reflects the volume of contrast material in a structure and is independent of flow rate. Cases with either larger aneurysms or stenosis were seen better with 3D-CTA, owing to the development of flow-related or motion artifacts on MRA. On the other hand, MRA was considered to be superior to 3D-CTA in some cases, in which calcium in the vessel wall or skull base obscured the anatomy of the aneurysms on images obtained by 3D-CTA represents a promising non-invasive method is concluded that 3D-CTA represents a promising non-invasive method for imaging the intracranial vasculature and is comperable with MRA techniques in demonstrating intracranial lesions.