Diagnostic Accuracy of MDCTA for Detection of Intracranial Aneurysm in Non Traumatic Subarachnoid Haemorrhage: A Cross-sectional Study

Abstract

Introduction: Non Traumatic Subarachnoid Haemorrhage (NTSAH) constitutes a neurological emergency. Multi-Detector Computed Tomographic Angiography (MDCTA) provides significant advantages over Digital Subtraction Angiography (DSA) owing to its immediacy, non invasiveness, and comparable diagnostic accuracy. This warrants exploration of its utility as a fully integrated component of routine imaging and therapeutic algorithm for NTSAH, replacing DSA. Aim: To evaluate the potential of MDCTA of the Circle of Willis (COW) in the detection of causes of NTSAH and compare its diagnostic accuracy with DSA and/or intraoperative findings. Materials and Methods: This cross-sectional study enrolled 45 patients with suspected or confirmed intracranial vascular abnormality or SAH, and subjected to non contrast enhanced Computed Tomography (CT) and MDCTA of the COW. MDCTA findings like aneurysms, Arteriovenous Malformations (AVM), their morphological characteristics and anatomical COW variations were contrasted with DSA/operative findings in 24 patients and MDCTA’s accuracy was calculated. The data was analysed using statistical software R (Ross Ihaka and Robert Gentleman) v.4.0.2, employing Kappa coefficient. The p-value ≤0.05 indicated statistical significance. Results: Total of 45 subjects (mean age: 47.16±17.4 years, 17 females and 28 males) were included in the study. The mean aneurysmal size was 7.6±7.2 mm. Grade 3 or 4 (dense) SAH (48.88%) and aneurysms <3 mm in size (48.89%) were most common. MDCTA showed sensitivity, specificity, and positive and negative predictive values of 89%, 79%, 84% and 85%, respectively. Kappa test revealed a substantial agreement between CTA and DSA (kappa coefficient=0.68). Conclusion: MDCTA is a rapid, minimally invasive, and reliable substitute to DSA in diagnosing and characterising associated aneurysms and AVM, in most cases of NTSAH, aiding in further management of such patients.