Okuyama T, Saito K, Hirano A, Takahashi A, Hashimoto Y, Inagaki T
Department of Neurosurgery, Kushiro Neurosurgical Hospital
Title
Diagnosis of unruptured cerebral aneurysms using magnetic
resonance angiography and three dimensional computed
tomographic angiography [Article in Japanese]
Source
No Shinkei Geka 1997 Dec;25(12):1073-1079
Abstract
The purpose of this study is to confirm the use of magnetic resonance (MR)
angiography and three-dimensional computed tomographic (3D CT) angiography,
in the screening of unruptured cerebral aneurysms. Sixty-six unruptured cerebral
aneurysms in forty-eight patients were examined by MR angiography, 3D CT
angiography and digital subtraction angiography (DSA). All cases underwent
surgery. Three out of sixty-six (4.5%) cerebral aneurysms detected by MR
angiography and 3D CT angiography were false positive. The false aneurysms
were located at the region of the internal carotid artery and the posterior
communicating artery, and were under 2.0mm in size. The diagnosis of the
infundibular dilatation at the junction of the internal carotid artery and the
posterior communicating artery remained difficult. The true positive diagnosis of
aneurysms using MR angiography or 3D CT angiography was 95.5%, in our
hospital. All unruptured cerebral aneurysms over 2.0mm in size were detected
correctly by using MR angiography and 3D CT angiography, as well as DSA. The
inadequate diagnosis of aneurysms caused by MR angiography was due to the
overlapping of vessels and the surrounding noise. Superselective maximum
intensity projection (MIP) and interactive vascular imaging (IVI) were adopted for
exact diagnosis. Furthermore, the three slab method of MR angiography was used
for containing the limits between the vertebral artery and the distal anterior
cerebral artery, and the triple method was able to decrease surrounding noise.
Using MR angiography, we diagnosed and operated on about 100 cases of
unruptured cerebral aneurysm in one year. Our conclusion is that we can diagnose
any unruptured cerebral aneurysm, over 2.0mm in size, using MR angiography
and 3D CT angiography.