Clinical Application of Susceptibility Weighted Imaging: Exploring from Routine Service

Abstract

To evaluate the usefulness of susceptibility weighted imaging (SWI) in clinical brain MRI. Retrospective study was performed after approval from institution Ethical Committee. The brain MRIs with SWI were selected from data base of the radiology department. Only cases with no abnormality in extra-axial location were included into the study. Two neuroradiologists revealed the images without knowledge of patients' history and diagnosis. The SWI was first interpreted. Then conventional MRI (cMRI) was interpreted after finishing data collection from SWI. Clinical data and final diagnosis were collected from information given on requested forms and followed up imaging studies. Descriptive analysis was performed. From January 2007 to December 2009, 82 cases were satisfied the inclusion criteria. There were 40 males and 42 females with age 7-79 years old (means = 47.45). The final diagnosis were normal brain imaging 4 cases (4.9%), dementia/atypical Parkinson disease 2 cases (2.4%), cerebrovascular disease 24 cases (29.3%), parenchymal brain tumors 35 cases (42.7%), infection 4 cases (4.9%), multiple sclerosis (MS) 6 cases (7.3%) and inconclusive diagnosis 7 cases (8.5%). The abnormalities found on SWI were related to cMRI in 67 cases (81.7%). Three cases (3.7%) had lesions on SWI not demonstrated on cMRI. The information got from SWI added on cMRI for interpretation and diagnosis in 43 cases (52.4%). SWI were shown more detectable microbleed and changing visualization of cortical and transmedullary veins. Microvascular structure inside the mass was demonstrated on SWI in brain tumor group. The increased transmedullary veins on SWI helped to confirm the non-neoplastic lesions. In selected cases with suspected or diagnosis of vascular disease and tumor, SWI added more information on cMRI especially microbleed and microvascular structure.