Role of Diffusion-weighted Imaging, Perfusion Magnetic Resonance Imaging, and Magnetic Resonance Spectroscopy in Evaluating Histopathologically Confirmed Brain Tumors in 3-Tesla Magnetic Resonance Imaging

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.

Posterior Fossa Lesions– An Experience Of 32 Cases Over 2 Years

INTRODUCTION- 1 Posterior fossa tumours are common in paediatric population ; however their occurrence in adults is not rare. They form a major cause of morbidity and mortality in either population. Some of these tumours like pilocytic astrocytomas are rewarding, others, like medulloblastomas may have a poor outcome. This study aims to analyse the epidemiology and surgical outcomes of posterior fossa lesions. MATERIALS AND METHODS – This is a retrospective study done at Dr. B.R.A.M. Hospital between April 2016 and June 2018. It included 32 patients with posterior fossa lesions.Cerebellopontine angle lesions- schwannomas, epidermoids were excluded. Only lesions involving the cerebellum or occupying the fourth ventricle were included in the study. Their surgical outcome in terms of complications and mortality were analysed. RESULTS-Thirty –two patients, in the age group of 2years to 68 years were included in the study. Cerebello-pontine angle lesions were excluded. Only lesions involving the cerebellum or occupying the fourth ventricle were included in the study. Most common lesion was medulloblastoma, followed by pilocytic astrocytoma, cerebellar abscess, haemangioblastoma, arachnoid cyst, exophytic tectal gliomas, tuberculoma, metastasis, epidermoid. They underwent surgery depending upon the nature of lesion. Overall mortality was found in 9 of 32 patients. Mortality was especially high in medulloblastoma patients (54.55%). CONCLUSIONS – Various lesions may affect the posterior fossa, varying from neoplastic malignant or benign lesions to infective and developmental lesions. Medulloblastoma is a common tumour in the paediatric population and carries a bad prognosis