Comparative Diagnostic Performance of CT and MRI in Acute Ischemic Stroke: A Retrospective Analysis From A Tertiary Care Center

Abstract

Objective:  This study sought to assess and juxtapose the diagnostic proficiency of non-contrast CT and MRI in acute ischemic stroke, focusing on infarct delineation, hemorrhagic conversion, and posterior circulation involvement.

Materials and Methods:  This retrospective observational study was conducted at the Department of Radiology, Lady Reading Hospital, Peshawar. A total of 200 patients aged 18 years or older, presenting with clinical suspicion of AIS, were included. All patients underwent both non-contrast CT and MRI within 24 hours of symptom onset. Imaging was reviewed independently by two experienced neuro-radiologists. Data on infarct detection, infarct volume, posterior circulation involvement, and hemorrhagic transformation were recorded.

Results:  MRI detected acute infarcts in 92% of patients, significantly more than CT (66%) (p < 0.001). In posterior circulation strokes, MRI identified 60 cases versus 24 on CT (p < 0.001). Detection of hemorrhagic transformation was similar between modalities (CT: 87.5%, MRI: 85.7%; p = 0.68). MRI showed higher diagnostic accuracy with a sensitivity of 92%, specificity of 87%, and AUC of 0.95, compared to CT (sensitivity: 66%, specificity: 81%, AUC: 0.75). MRI also identified larger infarct volumes (p < 0.01).

Conclusion:  MRI provides superior diagnostic performance in acute ischemic stroke, especially for early and posterior circulation infarcts, while CT remains crucial for initial hemorrhage exclusion. A combined approach may enhance diagnostic accuracy and improve outcomes in stroke care.