ABSTRACT
Objective To investigate the CT and MRI features of desmoid-type fibromatoses(DF).Methods The images of 29 ca-ses with DF proved by pathology were reviewed retrospectively.CT and MRI examinations were performed in 1 5 cases respectively, and both in 1 case.Results The median age was 33.0 years with a male-to-female sex ratio of 1 ︰ 2.2.36 lesions were discovered,among which 26 cases were solitary while 3 cases had multiple focus.1 9 lesions were extra-abdominal,14 ones in the abdominal wall and 3 ones intra-abdominal.The largest diameter of tumors was 13 -1 75 mm.27 lesions displayed ovoid or elongated shape while 9 ones were irregular .The boundary could be clear or unclear.25 lesions extended along muscle planes with consistent long axis.23 focuses grew aggressively,1 6 of which crossed the muscle clearance,while 13 lesions grew expansively.On CT,20 lesions appeared iso-den-sity or slightly hypo-density compared with normal muscles,mostly homogeneous(1 5/20).Most lesions exhibited gadually moderate or obvious enhancement on post-contrast CT,and the enhancement was homogeneous or heterogeneous.1 7 lesions were found on MRI,which presented signal intensity similar to or slightly higher than that of muscles on T1 WI and most were homogeneous(12/1 7);on T2 WI,all were heterogenous with slightly high or high intensity.All lesions demonstrated obvious enhancement on MRI after contrast administration ,and most were heterogeneous(12/1 7).Sheets or bands of low signal were detected within 1 1 lesions with no enhancement.Conclusion DF has some characteristics on CT and MRI,which are valuable for accurate pre-operative diagnosis,and for evaluation of the lesion extent and involvement of adjacent structures.