DIAGNOSTIC ACCURACY OF FLUID-ATTENUATED INVERSION-RECOVERY MAGNETIC RESONANCE IMAGING IN DETECTION OF ACUTE SUBARACHNOID HEMORRHAGE KEEPING LUMBER PUNCTURE AS GOLD STANDARD

OBJECTIVE: To determine the diagnostic accuracy of FLAIR MRI in identifying acute Subarachnoid Hemorrhage (SAH) using Lumber puncture (LP) as a gold standard. MATERIALS AND METHODS:  This was a validation study conducted from 3rd September 2020 to 3rd February 2021 at the Department of Radiology, Khyber Teaching Hospital, Peshawar. The sample size was 266. A non-probability consecutive sampling technique was used. All alert patients aged 20-70 years with sudden acute headache, other signs of SAH (nausea, vomiting, blurring of vision, sensitivity to light, and neck stiffness), and GCS >13 were included in this study. SAH on FLAIR-MRI was determined based on high signals in the subarachnoid space on FLAIR. Diagnostic accuracy was calculated regarding sensitivity, specificity, and positive and negative predictive values. SPSS version 22 was used to perform statistical analysis of the data.   RESULTS: Mean age ranged from 20 to 70 years (46.3 + 14.1 years), with 58.6% male, and 41.4% female subjects. On FLAIR-MRI, SAH was observed in 65.4% of patients while SAH was recorded in 57.5% on follow-up LP. Sensitivity of FLAIR-MRI was found to be 91.5% and specificity 69.9%. FLAIR-MRI has 80.5% positive predictive value and 85.8% negative predictive value. CONCLUSION: FLAIR-MRI is effective in accurately identifying SAH with high sensitivity and fair specificity. As such, it is a useful radiological tool for diagnosis of SAH in adults and further studies are recommended to confirm its usefulness. Keywords: Magnetic resonance imaging, lumber puncture, subarachnoid hemorrhage, headache