Clinical Values Of Susceptibility Weighted Imaging In Brain Tumor

PART ONE MANIFESTATIONS OF SUSCEPTIBILITY WEIGHTED IMAGING IN NORMAL BRAINOBJECTIVES:To evaluate the manifestations of SWI in normal brain by comparison SWI with conventional MRI sequences.MATERIALS AND METHODS:Five healthy volunteers were recruited into this research.They underwent routine MRI including T2WI,T2WI,FLAIR and SWI.Original images of SWI were transmitted to the work station(AW4.1)provided by GE,and Functool software was employed to process the data.After filtering of phase image and phase masking of magnitude image,5mm-20mm thickness minimum intensity projection(MinIP)was used to reconstruct the SWI images for analysis.RESULTS:Clear SWI images of 5 healthy volunteers were gained.Compared with the conventional MRI images(T2WI,T2WI and FLAIR),SWI showed better contrast of gray matter and white matter.The signal of cerebrospinal fluid was inhibited like FLAIR on SWI.Cerebral veins were clearly demonstrated on SWI reconstructed by MinIP including the slim linear low signals alone the sulci standing for the superficial cerebral veins and streak-like low signals in basal ganglia region representing deep cerebral veins.Normal intracerebral iron deposition was demonstrated in all volunteers showing the symmetrically distributed low signals in basal ganglia region and midbrain.Band-like low signal alone the cortex shown on SWI stood for the iron deposition in cortex.CONCLUSION:SWI is very sensitive to small veins and iron deposition of brain.It can show venous system of normal brain clearly and monitor the changes of distribution and concentration of normal brain iron deposition. PART TWO CLINICAL VALUES OF SUSCEPTIBILITY WEIGHTED IMAGING IN BRAIN TUMOROBJECTIVES:To evaluate the clinical values of susceptibility weighted imaging(SWI) in brain tumor.MATERIALS AND METHODS:A total of 71 cases from July 2008 to December 2008 with brain tumor proved by pathology and radiology included 20 meningiomas, 20 astrocytomas,8 glioblastomas,7 cavernous angiomas,4 metastatic tumors,2 ependymomas,4 neurilemomas,3 digodendrogliomas,2 pituitary adenomas,1 craniopharyngioma,2 medulloblastoma,1 hemangiopericytoma and 6 cases without brain tumor.They underwent routine MRI(T1WI,T2WI and FLAIR)and SWI.Of them, 41 underwent enhancement MRI scan and 35 underwent DWI.SWI images were analyzed to evaluate the diagnostic values of SWI in brain tumor.RESULTS:In the evaluation of blood products and venous vasculature SWI gave better information than all the standard squences(T1WI,T2WI,FLAIR,DWI and CE- T1).In the evaluation of internal architecture SWI gave better inforrmation than T1WI,T2WI,FLAIR and DWI,and show the complemented information obtained by conventional CE-T1 regarding the internal architecture of the lesions.CONCLUSION:SWI is very sensitive to hemorrhage and vein structure.SWI was proved useful for tumor characterization because of its ability to better highlight blood products and venous vasculature.SWI also has some advantage in delineation of the internal architecture.