Preliminary Evaluation Of Cerebral Amyloid Angiopathy By Using T2 Star Weighted Angiography (SWAN)

Purpose:To evaluate the radiologic findings of cerebral amyloid angiopathy(CAA) by using of T2 star weighted angiography(SWAN) technique and T2~* GRE technique and to find the evidence to prove which one was more suitable for the diagnosis of CAA by comparing the images.Materials and Methods:42 patients(≧70 years,with clinical symptoms) underwent MR T1WI,T2WI,DWI,T2~* GRE sequence,SWAN examination on a 3.0T scanner,of which 15 patients with the imaging evidence of probable CAA or possible CAA were selected.CNR of the leisions on theT2~* GRE images and were analyzed statistically.Results:Traditional T2~* GRE images demonstrated 86 microhemorrhage leisions in cortical-subcortical reigion in 15 patients with CAA,while SWAN images demonstrated 206 leisions,including 46 in frontal lobe,47 in parietal lobe,59 in temporal lobe,46 in occipital lobe and 8 in cerebellar hemisphere. The number of leisions on T2~* GRE images was approximately 41.7 percent as many as the latter.SWAN images had higher CNR than traditional T2~* GRE images.The leisions on SWAN images with smaller CI and diameter were less possible to be demonstrated on T2~* GRE images.Conclusion:SWAN was a relatively new technique that was sensitive to magnetic susceptibility comparing with T2~* GRE images.SWAN images with higher resolution and CNR identified many more microhemorrhages than conventional T2~* GRE images and lead to early detection of microhemorrhage. Improved detection of microhemorrhage may become increasingly important in the diagnosis,management,and monitoring of the therapeutic response of patients with CAA...