Study of Screening Test for Cerebral Aneurysms

Abstract

Recent diagnostic innovations such as CT and digital subtraction angiography (DSA) have been increasing our ability to identify intracranial aneurysms safely and accurately. However, the overall results of management of aneurysmal subarachnoid hemorrhage, especially catastrophic hemorrhage, have not improved proportionately. This is because the risk factors for development of aneurysm remain unknown and traditional surgery has been planned after subarachnoid hemorrhage.
In this report the authors studied the effectiveness of intravenous DSA (IVDSA) for evaluation of the diagnosis of aneurysms before they rupture. Compared with conventional angiography, the diagnostic accuracy of DSA was 71.9% for 64 aneurysms (58 cases including 34 with rupture). Its diagnostic rate was limited by the size and location. In our clinical experience, aneurysms larger than 4mm have been directly diagnosed by DSA. However, because of the limited space-resolution of DSA, it cannot replace conventional angiography for evaluating the details of small aneurysms. It was necessary to perform repeated DSA by adapting the multiple directions of the injection in order to obtain precise imagings of vascular structures. False positive and misleading findings of aneurysms on DSA were due to the morphological complexities of arterial junctions and incorporated nodular densities with normal cerebral arteries and misregistration due to motion. Several representative cases were demonstrated.
In conclusion, a detailed knowledge of the vascular structure and factors simulating cerebral aneurysms will improve the diagnostic rates of unruptured aneurysms by means of IVDSA.