Comparative Diagnostic Role of Computed Tomography Angiography (CTA) and Noncontrast Magnetic Resonance Angiography (NC-MRA) in Evaluation of Cerebrovascular Accidents

Abstract

Background: Cerebrovascular accidents (CVA) are a major cause of mortality and morbidity in middle and elderly agegroups. It can be ischemic or hemorrhagic and thrombotic or embolic. Digital subtraction angiography (DSA) is a gold standard investigation for evaluating patients with CVA. Due to invasive nature of DSA, computed tomography angiography (CTA) has long been used as a primary noninvasive imaging tool to evaluated patients with CVA. Angiography can also be performed with magnetic resonance imaging, both with & without contrast. Introduction: CTA serves as a primary noninvasive imaging tool in evaluation of patients with CVA as nearly half of these patients do not have treatable underlying cause. Due to increasing awareness regarding the radiation exposure, contrast-induced nephrotoxicity and iodinesensitivity, magnetic resonance angiography (MRA) is gaining more and more attention. Noncontrast MRA (NC-MRA) can be performed utilizing 3D-time of flight sequence which provides results comparable to that of CTA. Hence, we performed a study to evaluate comparable role of NC-MRA and CTA. Methods: Fifty patients with cerebrovascular accidents were evaluated with CTA & NC-MRA in tandem on the same day. The results obtained were statistically evaluated and conclusions were drawn. Results & Conclusions: Detection of aneurysm in intracranial and stenoses in intracranial as well as extracranial vessels can be detected with good accuracy by NC-MRA. The results of NC-MRA was comparable to that obtained by CTA except in very small aneurysm (<3mm) and early stenosis (20-30%) which rarely affect immediate patient management. Hence, NC-MRA can be a good substitute to CTA especially in patients where iodinated contrast is relatively or absolutely contraindicated and in combination with routine protocol for stroke imaging.