| Purpopse Subarachnoid haemorrhage (SAH), due to rupture of anintracranial aneurysm, is a serious disorder with a high mortality and morbidity.It account for about one-quarter of cerebrovascular deaths and,despite improvement in the management of patients with SAH, the case-fatality rate is still reported as between 25 and 50%, with most patients dying as a result of the initial bleed or its immediate complications. Of suvivers,about 50% will be left disabled and dependent on others in activities of daily living. SAH is due to rupture of a saccular aneurysms in ~75% of cases, which usually arise from the circle of Wills or branch artery. So the diagnosis of the aneurysms is very important for treatment of SAH. The accepted reference standerd for identification of intracranial aneurysms is intraarterial digital substraction angiography. During the past decade , there has been considerable interest in the roleof noninvasive imaging in the detection of intracranial aneurysms. there have been numerous studies to compare either magnetic resonance(MR) angiography or computed tomography(CT) angiography with intraarterial DSA. The result of these studies indicate that CT angiography and MR angiography have a similar overall accuracy of about 90% but a sensitivity ranging from 0.67 (95%CI 0.55-0.78) to 1.0 (95%CI 0. 85-1)Material and methods for CT angiography and from 0.70 (95%CI 0.5-0.86) to 0.97 (95%CI 0. 87-1) for MR angiography. The diagnosis performance of CTA and MRA for detection of aneurysms larger than 5 mm is excellent. But the accuracy of detection for the aneurysms smaller than 3 mm is poor, we retrospectively analysised the angiography examinations performed during in our study which included the noninvasive angiography and intraartery DSA .The advantage and disadvantag of the noninvasive angiograpy(CTA or MRA) and intraartery DSA were discussed.The size and location of the aneurysms also influenced the accuracy of the detection.Materials and MethodsMaterials All 40 cases were derived from the SAH patients which were hospitalized in our hospital from 2000 to 2003. The patients(23 men, 17 female;media age ,48.7 years;age range ,22-68) who met the inclusin criteria were identified by the CT or Lumbar Puncture.Methods All the 40 patients were underwent intraarterial DSA andnoinvasive angiography(CTA or MRA). 23 patients were examed by CT angiography in additional to intraarterial DSA, and 17 cases were underwent by MR angiography and intraarterial DSA contemporaneously. CT examination was underwent spiral CT angiography with SIEMENS somatom volume Zoom scanner, the images were obtained by volume rendering method.MR angiography was underwent SIEMENS sonata 1. 5T unit with three-dimensional time-of-1ight sequence.ResultsIn all of the 40 patients , aneurysms were found in 26 cases in which 27 aneurysms detected, including one bilateral middle cerebral artery aneurysm. Intraarterial DSA found the 25 in all the 27 aneurysms. 23patients were examed by CT angiography in additional to intraarterial DSA, in which DSA found 15 lesions,CT angiography detected 12 aneurysms but missed 3. At the same time , CT found the 2 lesions missed by DSA. 17 cases were underwent by MR angiography and intraarterial DSA contemporaneously,in which 10 lesions were found by DSA , but only 5 aneurysms were detected by MR angiography.Compared with intraarterial DSA , the accuracy of the CT angiography and MR angiography were 80% (12/15)and 50% (5/10)0 The size of all the 10 aneurysms missed by the examination is less than 5 mm, especially 8 of them were smaller than 3 mm.Conclusion1 Although there were risk associated with the intraarterial DSA , it wasthe best disgnosis way of detecting aneurysms, especially screening thesmall aneurysms. 2, CTA and MRA are important complementary examination methods to detectaneurysm .The aneurysm which smaller than 3mm is often missed bynoninvasive angiography. 3 Angiography methods which include DSA, CTA and MRA underwent properlywas benefit to di...
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