Aneurysmal subarachnoid hemorrhage diagnosis with computed tomographic angiography and OsiriX.
OBJECTIVE
Recent advances in computed tomographic angiography (CTA) have resulted in its replacing digital subtraction angiography (DSA). However, CTA requires a powerful workstation and experienced technicians for image postprocessing. OsiriX, a free open-source medical imaging software with powerful three-dimensional (3D) capability, enables neurosurgeons to perform 3D rendering without extensive training. In this study, we examined the sensitivity and specificity of CTA with OsiriX as the primary diagnostic tool for intracranial aneurysms.


METHODS
From May 2006 to March 2009, 121 patients with spontaneous subarachnoid hemorrhage (SAH) underwent CTA. The CTA source images were 3D rendered by neurosurgeons using OsiriX. All the possible locations for aneurysms were carefully reviewed. DSA was performed on every patient in any of the following conditions: for negative CTA findings, after surgical clipping of aneurysms or before transarterial embolization of aneurysms.


RESULTS
Of the 121 patients, 8 were excluded because DSA data were not available. In the remaining 113 patients, 20 patients had negative CTA findings. CTA with OsiriX detected 106 aneurysms in 93 patients, of which 103 were confirmed by DSA or postoperative DSA; 3 infundibular dilated pouches of small arteries were mistaken for aneurysms. Two anterior communicating artery aneurysms (1.5 mm and 1 mm) were missed by CTA from among all 113 patients. The sensitivity and specificity of CTA for detecting aneurysms on a per-patient basis were 98.9% and 100%, respectively. The sensitivity and specificity of CTA for detecting aneurysms on a per-aneurysm basis for detecting aneurysms were 98.1% and 86.3%, respectively.


CONCLUSIONS
CTA with OsiriX enables accurate detection of intracranial aneurysms. Cerebral DSA should be reserved for those patients with negative CTA findings.
Department of Neurosurgery, Chang Gung University & Chang Gung Memorial Hospital, Taoyuan, Taiwan, Republic of China. stroke2000@gmail.com
Yi-Chou
YC
Wang
Yuan-Chang
YC
Liu
Tsung-Che
TC
Hsieh
Shih-Tseng
ST
Lee
Ming-Lung
ML
Li
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography / Q000379:methods*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D003951:Diagnostic Errors; D004621:Embolization, Therapeutic; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012984:Software; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D013346:Subarachnoid Space / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult