DIFFUSION WEIGHTED MAGNETIC RESONANCE IMAGING FEATURES OF INTRA AND EXTRAAXIAL INTRACRANIAL PATHOLOGIES

Dr. KIRTI TANTIA; Dr. G.L.MEENA

Volume : V, Issue : V, May - 2016

DIFFUSION WEIGHTED MAGNETIC RESONANCE IMAGING FEATURES OF INTRA AND EXTRAAXIAL INTRACRANIAL PATHOLOGIES

Dr. Kirti Tantia, Dr. G. L. Meena

Abstract :

To discuss the diffusion weighted imaging features of intra and extra–axial intracranial pathologies and to compare them with T2 and T2 FLAIR imaging. Methodology: A descriptive MRI Study was done in 150 patients with intracranial pathologies. In all these patients DWI, ADC, T2 and FLAIR findings were noted. RESULTS: Majority (47%) of cases were infarcts, All acute infarcts, 50% sub–acute infarcts and none of chronic infarcts showed restriction on DWI. In 13% of acute infarcts, no signal change was evident on T2WI. All cases of HIE showed restricted diffusion, while on T2WI, no signal change was seen in 20% cases. 42.85% of tubercular granulomas, 100% of abscesses and 50% of meningoencephalitis showed diffusion restriction while no case of NCC showed restriction. Among intra–axial tumours, 80% medulloblastomas, 40% glioblastoma multiforme and 33.33% metastases showed restricted diffusion but none of the low grade gliomas or anaplastic astrocytomas showed diffusion restriction . Among extra–axial lesions, 14% meningiomas and all epidermoid cysts showed diffusion restriction while none of the schwannomas or arachnoid cysts showed restricted diffusion. No case of PRES and only 25% of demyelinaton cases showed restricted diffusion. CONCLUSION: DWI is an excellent modality for the detection and characterization of infarcts and HIE as compared to T2 & T2 FLAIR. Tumours having high cellularity such as glioblastoma multiforme, medulloblastoma and meningioma may show restricted diffusion. Presence of diffusion restriction is a useful method of differentiating epidermoid cyst from arachnoid cyst and abscesses from necrotic tumours