Pitfalls in the use of Multidetector Row CT Angiography for Identification of Intracranial Vascular Abnormalities : Focus on the Various Radiological Findings

Kim, Yong Sang; Cho, Byung Moon; Cho, Sung Min; Park, Se Hyuck; Oh, Sae Moon

Abstract

OBJECTIVE
Multidetector-Row computed tomographic angiography (MDCTA) is a promising method for detection and surgical planning of intracranial vascular abnormalities. However, there are several problems, such as image degradation due to inevitable patients movement, venous contamination, kissing vessel artifact, demonstration of venous structures mimicking aneurysm and bone artifacts. The purpose of our study is to review our recent experience with false negative or positive cases on MDCTA.
METHODS
Between May 2007 and May 2010, 259 consecutive patients, who were diagnosed with intracranial aneurysms or other vascular abnormalities by MDCTA, were retrospectively reviewed. Among the 259 patients, 172 patients who underwent digital subtraction angiography (DSA), which was considered as the standard of reference, were included in the study. Two neuroradiologists and two neurosurgeons evaluated independently and separately all of the MDCTA images.
RESULTS
A total 26 cases (15.3%) were revealed abnormal vascular findings on MDCTA. There were 11 false negatives on MDCTA including incomplete scanning range of lesion site (n=3), a blood blister aneurysm (n=1), severe vasospasm (n=4) and bone artifacts (n=3). Also there were 15 false positives on MDCTA; venous contamination over the lesion site (n=6), focal dilation of the bifurcation or branching site of major vessels (n=6) and poor quality of the images due to inevitable patients movement (n=3).
CONCLUSIONS
MDCTA is clearly not the total answer for aneurysm diagnosis. We recommend that MDCTA scanning range is planned to encompass the whole intracerebral vasculature. Close attention to image acquisition and interpretation are required to reduce errors in MDCTA of intracranial aneurysms.