Sensitivity of the neuroimaging techniques in ischemic stroke.

The aim of this study was to investigate and compare the sensitivity and effectiveness of neuroimaging techniques in 190 patients with acute ischemic stroke. The first computed tomography (CT) scan for all patients was performed within the first 12 hours of the stroke symptoms onset. For each patient, between the third and fifth day of the hospitalization, at least one more neuroimaging procedure (CT and/or magnetic resonance imaging--MRI, and/or diffusion weighted imaging--DWI) was done. The CT scan in the first 12 hours of the stroke onset was positive in 32% of the patients; the highest number of the positive findings was in the patients with total anterior circulation infarct (52%). After 48 hours of the stroke onset second CT was positive in 85% (75/89), MRI in 93.5% (115/123), and DWI in 98.8% (79/80) patients. MRI was significantly more sensitive than CT in detection of ischemic lesion (88% vs. 72%, P=0.01), particularly in the patients with lacunar infarcts (75% vs. 50%, P=0.005). In detection of ischemic stroke 48 hours of the stroke onset the slightly higher number of strokes were detected on DWI in comparison with MRI (98.6% vs. 88.7%). According to our results, within the first 12 hours after the stroke onset, CT is reliable only for detection of considerable number of cortical ischemic strokes of the anterior cerebral circulation. After 48 hours from the stroke onset CT, MRI and DWI show high sensitivity in the detection of ischemic lesion of all clinical stroke subtypes. MRI is more sensitive in comparison with CT in detection of ischemic lesion, while DWI does not show dominance in comparison with MRI in identification of ischemic stroke after 48 hours of the symptoms onset.