Résumé
Objective: Our aim was to evaluate the diagnostic capabilities of physiological magnetic resonance imaging (MRI) in differentiatingtype and grades of tumor and correlation with prospective histopathology results.Materials and Methods: We evaluated 70 patients in 3-tesla MRI preoperatively using conventional and physiological MRsequences (diffusion, perfusion, and spectroscopy) of common brain tumors who were prospectively confirmed by histopathology.Post-imaging analysis was done by available software and ratio was calculated. Data were expressed as mean ± standarddeviation and median (range) and Kolmogorov–Smirnov analysis was used to check distribution. Multiple statistical tests wereapplied and receiver operating characteristic (ROC) curve was plotted wherever feasible.Results: We obtained a significant difference in spectroscopic parameters, relative cerebral blood volume, and apparent diffusioncoefficient values between different tumor groups and also between different tumor grades. ROC curve plotted among groupsshowed sensitivity and specificity of diagnostic capability. Time-intensity curve showed a significant difference between differenttumor groups and correlation with grades of tumor.Conclusion: We propose an algorithm for differentiating different types and grades of common brain tumor using physiologicalMRI in addition to conventional MR sequences.
Résumé
context: Cerebral venous sinus thrombosis (CVST) previously believed to be an uncommon cerebrovascular event, accounting for0.5–1% of cases of stroke, affecting 1.32/100,000 person/year. CVST is a disease of young adults (<50 years old) predominantlyand is diagnosed based on clinical suspicion with confirmatory neuroimaging.Aims: This study aims to prospectively evaluate the Hounsfield unit (H.U) value of cerebral venous sinus on non-contrastcomputerized tomography (NCCT) scan and to assess its predictive value in diagnosing cerebral venous thrombosis and toevaluate whether standardizing venous sinus H.U value measurements to those of the corresponding internal cerebral arterywould improve diagnostic accuracy.Materials and Methods: In our study, a total of 80 clinically suspected case of CVST were included and NCCT head scan was donethen confirmed by M.R. venography (gold standard). Of 80 cases, a total of 38 cases were diagnosed as CVST on M.R. venographywhich was considered as Group B and rest 42 cases were normal on M.R. venography which was considered as Group A.Statistical Analysis: Average HU and H:H ratio were compared using two-tailed t-test, and linear regression analysis wasused to assess correlation between hematocrit (HCT) and HU.Results: Linear regression analysis showed positive correlation between HCT with computed tomography attenuation (HU)among both the groups (P < 0.005). H:H ratio (HU/HCT) for cutoff point of 1.645 had sensitivity of 71.1%, 97.6% specificity,and 96.4% PPV. A cutoff value of 1.335 for standardized measurement with internal carotid arteries (ICA) had 71.1% sensitivity,81% specificity, and 77.1% PPV.Conclusion: We conclude that average HU, H:H ratio, and standardized with ICA were the best predictor for sinus thrombosis.