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International Journal of Recent Trends in Science and Technology, ISSN 2277-2812 E-ISSN: 2249-8109
Volume 12, Issue 2, September 2014 pp 425-430
Signal intensity features of intracranial lesions on diffusion weighted magnetic resonance imaging
Richard Thomas1, Ravi Hoisala2
1SR.Resident, 2Professor and HOD, Department of Radiodiagnosis, St John’s Medical College Hospital, Bangalore-560034, Karnataka, INDIA.
Introduction: Diffusion weighted imaging is an essential sequence to be included in any ptotocol for magnetic resonance imaging of the brain and therefore it is essential to study the signal intensity features of intracranial lesions in this sequence. Aims: To describe the signal intensities of intracranial lesions on diffusion weighted imaging and to compare this with apparent diffusion coefficient maps. Methods and Materials: Images of 115 patients who underwent magnetic resonance imaging at our hospital from March 2010 to March 2011 were prospectively studied. The signal intensities of various lesions on diffusion weighted images, apparent diffusion coefficient maps were studied. Statistical analysis used: Percentages of individual intra and extra cranial lesions that showed diffusion restriction, increased diffusivity or isointense signal relative to gray matter were calculated. Results: All cases of acute infarcts, hypoxic ischemic injury, abscesses and extradural empyemas showed diffusion restriction. 50% of subacute infarcts, 33% of tuberculomas, 40% of GBM, 75% of medulloblastomas, 33% of meningiomas, single case of epidermoid cyst and 50% of lymphomas showed true restriction of diffusion. The remaining cases showed increased diffusivity or intermediate signal intensity. Conclusion: Intracranial lesions show a varied appearance on diffusion weighted imaging and this sequence is an important tool in establishing an accurate diagnosis.