Role of digital subtraction angiography in detection of intracranial aneurysms compared with computed tomographic angiography

S Maniharan,D L N Pullaperuma,S Pirasath,I N Lekamge,A D P Athukorala

doi:10.4038/sljr.v5i1.76

Abstract

Objective To evaluate the role of digital subtraction angiography (DSA) in the detection of intracranial aneurysms among patients with spontaneous subarachnoid hemorrhage (SAH) compared with computed tomographic angiography (CTA) in a single center, Sri Lanka. Methods A total of 123 patients clinically and CT proven SAH were evaluated with CT angiography and DSA with a median interval of 3 days. The sensitivity, specificity and accuracy of CT angiography in detecting aneurysms were analyzed compared to DSA on a per-patient, per-size, per-site and per morphological basis. All data were analyzed using SPSS analytical package (version 18). Ethical approval for the study was from the institutional ethical review board. Results Among 123 patients with clinically and CT proven SAH, 51 (41.5%) patients showed aneurysms on CT angiography. 72 were negative for aneurysms in CTA. In 13 out of 72 (18%) CTA negative patients subsequent DSA demonstrated aneurysms. Number of CTA negative but DSA positive aneurysm were 15 as two of the patients had two aneurysms each. Four CTA detected aneurysms could not be appreciated in the subsequent DSAs. Aneurysms (47)detected by both CT angiography and DSA were more than 6mm in size (56.7%) , sacculartype (96.5%) and were located in the anterior circulation system (92.4%). Most CTA negative aneurysms detected by DSA were less than 6mm in size (80%), saccular type (60%) and were located in anterior (53.8%) and posterior (46.7%) circulation system. The sensitivity, specificity, positive predictive value and negative predictive value of CT angiography compared to DSA per patient basis were 78.3%, 93.7%, 92.2% and 81.9% respectively. CT angiography has a low sensitivity to detect aneurysms less than 6mm size (65.7%%), in posterior circulation (36.4%) and other morphological types (0%) compared to aneurysms more than 6mm size (90.9%), in anterior circulation (85.9%) and saccular type (85.5%). Conclusion Digital subtraction angiography (DSA) has a significant role in detecting intracranial aneurysms which are less than 6mm in size, are located in posterior circulation system and of non-saccular morphological type.

Highlights

Subarachnoid haemorrhage is associated with high mortality and morbidity[1] and is a health burden globally with an incidence rate of 9 per 100000 populations per year[2]
Digital subtraction angiography (DSA) has a significant role in detecting intracranial aneurysms which are less than 6mm in size, are located in posterior circulation system and of non-saccular morphological type
Among 123 patients with clinically and CT proven subarachnoid hemorrhage (SAH), 51 (41.5%) patients had aneurysms while 72 (58.5%) patients had no detectable aneurysms at CT angiography

Summary

Introduction

Subarachnoid haemorrhage is associated with high mortality and morbidity[1] and is a health burden globally with an incidence rate of 9 per 100000 populations per year[2]. Re-bleeding is common and can be catastrophic. Delayed cerebral ischemia is a common complication usually occurring in around 33% of patients between 4 to 14 days from the onset of SAH2. Recognition and prompt treatment of underlying etiology reduces the morbidity and mortality and leads to better outcomes among victims. The current accepted practice in patients with spontaneous SAH is either CT angiography and/or Digital Subtraction Angiography (DSA) with a view to detect the underlying etiology of bleeding. DSA is the gold standard investigation[3] to detect intracranial aneurysms, which is an invasive and time-consuming imaging modality and needs to be performed by experienced operators

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Results

Discussion

Conclusion