Detection of acute small amount of subarachnoid hemorrhage: Comparison between fluid-attenuated inversion recovery MR imaging and CT

PurposeTo evaluate the possibility of detecting small amount of acute subarachnoid hemorrhage (ASH) diluted by CSF not revealed by CT but identified on fluid-attenuated inversion recovery (FLAIR) MRI.Patients and methods50 patients with acute neurological symptoms were referred from the neurosurgery department to the radiodiagnosis department for computed tomography CT and magnetic resonance imaging MRI examination.ResultsLumbar puncture proved 41 positive cases, MRI (FLAIR) interpreted 43 positive cases (40 true positive and 3 false positive) and 7 negative cases (6 true negative and one false negative) while CT interpreted 39 positive cases (37 true positive and 2 false positive) and 11 negative cases (7 true negative and 4 false negative).ConclusionFLAIR MRI was more sensitive and more accurate in the diagnosis of acute SAH than CT scan, having a much higher negative predictive value to exclude acute SAH, however its positive predictive value was slightly lower than CT, but there was no statistically significant difference statistically between the two in diagnosis of SAH.