MORPHOLOGICAL PARAMETERS FOR RUPTURE RISK ASSESSMENT OF MCA (MIDDLE CEREBRAL ARTERIES) ANEURYSMS BY CTA (COMPUTED TOMOGRAPHY ANGIOGRAPHY)

ABSTRACT Background: Rupture of Intracranial aneurysms is one of the major causes of subarachnoid haemorrhage. Identifying aneurysm for impending rupture allows clinician to timely intervene thus preventing possible complications resulting from aneurysm rupture. Objective: To evaluate the impact of morphologic factors on multiple intracranial aneurysms on the image-based model obtained from 3D-CTA (Computed tomography angiography) and compared different morphological indices in their significance for describing the risk of rupture in a given aneurysm. Methods: Total of 115 patients harboring single and/or multiple intracranial aneurysms with 126 saccular Middle cerebral arteries (MCA) aneurysms (72 ruptured and 54 unruptured) were analyzed from 3D-CTA images. Morphologic parameters were evaluated for significance with respect to rupture. Receiver operating characteristic (ROC) analysis identified area under the curve (AUC) and optimal thresholds separating ruptured from unruptured intracranial aneurysms for each parameter. Significant parameters were examined by Multivariate logistic regression analysis to identify independent discriminators. Results: Nine morphologic parameters  (5 size indices - neck width, aneurysm depth, aneurysm maximum height,  aneurysm maximum width and aneurysm volume and 4 shape indices -  Aspect ratio, size ratio, height to width ratio and neck vessel ratio)  achieved statistical significance (p ≤ 0.05). Size ratio (SR) was the independently significant rupture factor with its statistical significance ( p ≤0. 001) and AUC (0.78). Conclusions: Among all 3D-CTA morphological parameters, SR found to be the most important and significant factor in evaluating the risk of rupture in a given aneurysm. Keywords:  aneurysms rupture risk; computed tomography angiography; middle cerebral arteries aneurysms; size ratio.