[1] North Eastern Indira Gandhi Reg Inst Hlth & Med S, Dept Internal Med, Shillong, Meghalaya, India
[2] North Eastern Indira Gandhi Reg Inst Hlth & Med S, Dept Radiol & Imaging, Shillong 793018, Meghalaya, India
[3] All India Inst Med Sci, Dept Neuroimaging & Intervent Neuroradiol, New Delhi, India