Anderson G B, Findlay J M, Steinke D E, Ashforth R
Division of Neurosurgery, University of Alberta, Edmonton, Canada.
Neurosurgery. 1997 Sep;41(3):522-7; discussion 527-8. doi: 10.1097/00006123-199709000-00003.
To objectively compare computed tomographic angiography (CTA) with selective digital subtraction angiography (DSA) in the detection and anatomic definition of intracranial aneurysms, particularly in the setting of acute subarachnoid hemorrhage (SAH).
In a blinded prospective study, 40 patients with known or suspected intracranial saccular aneurysms underwent both CTA and DSA, including 32 consecutive patients with SAH in whom CTA was performed after CT images were obtained diagnostic for SAH. The CT angiograms were interpreted for presence, location, and size of the aneurysms, and anatomic features, such as the number of aneurysms lobes, aneurysm neck size (< or = 4 mm), and the number of adjacent arterial branches were suggested. The images obtained with CTA were then compared with the images obtained with DSA, with the later images serving as controls.
DSA revealed 43 aneurysms in 30 patients and ruled out intracranial aneurysms in the remaining 10 patients. For aneurysm presence alone, the sensitivity and specificity for CTA was 86 and 90%, respectively. For the presence of an aneurysms, six CT angiogram showed false negative results and one CT angiogram showed a false positive result. False negative results were usually caused by technical problems with the image, tiny aneurysm domes (< 3 mm), and unusual aneurysm locations (i.e., intracavernous carotid or posterior inferior cerebellar artery aneurysms). The results obtained with CTA were, compared with the results obtained with DSA, more than 95% accurate in determining dome and neck size of aneurysm, aneurysm lobularity, and the presence and number of adjacent arterial branches. In addition, CTA provided a three-dimensional representation of the aneurysmal lesion, which was considered useful for surgical planning.
CTA is useful for rapid and relatively noninvasive detection of aneurysms in common locations, and the anatomic information provided in images showing positive results is at least equivalent to that provided by DSA. In cases of SAH in which the nonaugmented CT and CTA results indicate a clear source of bleeding and provide adequate anatomic detail, we think it is possible to forego DSA before urgent early aneurysm surgery. In all other cases, DSA is indicated.
客观比较计算机断层血管造影（CTA）与选择性数字减影血管造影（DSA）在颅内动脉瘤检测及解剖学定义方面的效果，尤其是在急性蛛网膜下腔出血（SAH）的情况下。
在一项盲法前瞻性研究中，40例已知或疑似颅内囊状动脉瘤患者同时接受了CTA和DSA检查，其中包括32例连续的SAH患者，这些患者在CT图像诊断为SAH后进行了CTA检查。对CT血管造影图像进行解读，以确定动脉瘤的存在、位置和大小，并提示其解剖特征，如动脉瘤叶数、动脉瘤颈大小（≤4mm）以及相邻动脉分支数量。然后将CTA获得的图像与DSA获得的图像进行比较，以DSA图像作为对照。
DSA显示30例患者中有43个动脉瘤，并排除了其余10例患者的颅内动脉瘤。仅就动脉瘤的存在而言，CTA的敏感性和特异性分别为86%和90%。对于动脉瘤的存在，6例CT血管造影显示假阴性结果，1例CT血管造影显示假阳性结果。假阴性结果通常由图像技术问题、微小动脉瘤瘤顶（<3mm）以及不寻常的动脉瘤位置（即海绵窦内颈内动脉或小脑后下动脉动脉瘤）引起。与DSA获得的结果相比，CTA在确定动脉瘤瘤顶和瘤颈大小、动脉瘤分叶情况以及相邻动脉分支的存在和数量方面的准确率超过95%。此外，CTA提供了动脉瘤病变的三维图像，这被认为对手术规划有用。
CTA有助于快速且相对无创地检测常见部位的动脉瘤，阳性结果图像中提供的解剖信息至少与DSA提供的相当。在SAH病例中，如果平扫CT和CTA结果显示明确的出血源并提供了足够的解剖细节，我们认为在紧急早期动脉瘤手术前可以不进行DSA检查。在所有其他情况下，则需要进行DSA检查。
