Objective To investigate the MRI manifestations of alveolar soft part sarcoma(ASPS)and to improve the diagnostic accuracy of ASPS.Methods The clinical and MRI data of 9 patients with ASPS confirmed by surgical pathology were analyzed ret-rospectively,and the MRI features were summarized and analyzed.Results Four cases were located in the thigh,three cases in the pelvis,one case in the calf,and one case under the chin.Seven cases were spindle shaped,one case was irregular,and one case was quasi-circular.All nine cases had clear boundaries.Seven cases of ASPS had lung metastases,and two of these also had brain metasta-ses.On T1WI,three cases showed isointense signals,and six cases showed slightly hyperintense signals.On T2WI,seven cases showed mixed hyperintense signals and two cases showed homogeneous hyperintense signals.On diffusion weighted imaging(DWI),six cases showed mixed hyperintense signals,one case showed homogeneous hyperintense signals,and one case showed isointense sig-nal;the average apparent diffusion coefficient(ADC)value was(1.14±0.10)×10-3 mm2/s.Six cases showed inhomogeneous obvious enhancement,and one case showed homogeneous enhancement;three cases showed relatively obvious enhancement in small strip-like fat suppression(FS)-T2WI hyperintense areas of ASPS.All nine cases of ASPS showed"flow void vessels sign",with seven cases showed"flow void vessels"both intratumor and peritumor,while the other two cases showed"flow void vessels"only peritumor.Six cases of ASPS showed cystic changes and necrosis.Three cases showed"pseudocapsule".Two cases showed T2WI hypointense septa-tion.Conclusion Hyperintense signals on T1WI,"flow void vessels sign"on T2WI,and inhomogeneous obvious enhancement in ASPS are helpful for diagnosis,with final confirmation relying on pathology.

Objective To investigate the MRI manifestations of alveolar soft part sarcoma(ASPS)and to improve the diagnostic accuracy of ASPS.Methods The clinical and MRI data of 9 patients with ASPS confirmed by surgical pathology were analyzed ret-rospectively,and the MRI features were summarized and analyzed.Results Four cases were located in the thigh,three cases in the pelvis,one case in the calf,and one case under the chin.Seven cases were spindle shaped,one case was irregular,and one case was quasi-circular.All nine cases had clear boundaries.Seven cases of ASPS had lung metastases,and two of these also had brain metasta-ses.On T1WI,three cases showed isointense signals,and six cases showed slightly hyperintense signals.On T2WI,seven cases showed mixed hyperintense signals and two cases showed homogeneous hyperintense signals.On diffusion weighted imaging(DWI),six cases showed mixed hyperintense signals,one case showed homogeneous hyperintense signals,and one case showed isointense sig-nal;the average apparent diffusion coefficient(ADC)value was(1.14±0.10)×10-3 mm2/s.Six cases showed inhomogeneous obvious enhancement,and one case showed homogeneous enhancement;three cases showed relatively obvious enhancement in small strip-like fat suppression(FS)-T2WI hyperintense areas of ASPS.All nine cases of ASPS showed"flow void vessels sign",with seven cases showed"flow void vessels"both intratumor and peritumor,while the other two cases showed"flow void vessels"only peritumor.Six cases of ASPS showed cystic changes and necrosis.Three cases showed"pseudocapsule".Two cases showed T2WI hypointense septa-tion.Conclusion Hyperintense signals on T1WI,"flow void vessels sign"on T2WI,and inhomogeneous obvious enhancement in ASPS are helpful for diagnosis,with final confirmation relying on pathology.

Objective To explore the CT and MRI characteristic manifestations of nodular fasciitis(NF).Methods A retrospec-tive analysis was conducted on the imaging data of 27 cases pathologically confirmed NF,and their special CT and MRI signs were analyzed.Among them,21 cases underwent MRI examination,14 cases underwent CT examination,and another 8 cases underwent both CT and MRI examinations.Results Among the 27 cases of NF,16 cases were subcutaneous type,4 cases were intramuscular type,and 7 cases were intermuscular(fascial)type.Eleven cases were located in the head and neck,8 cases in the trunk,6 cases in the upper limbs,and 2 cases in the lower limbs.Fourteen cases underwent CT plain scan,and all lesions showed slightly low density,while 1 case showed mild enhancement on CT enhanced scan.On T1 WI,19 cases showed iso-or slightly hypointense signals,and 2 cases showed slightly hyperintense signals.On T2WI,16 cases showed inhomogeneous hyperintense signals and 5 cases showed homoge-neous hyperintense signals.Fifteen cases showed mixed hyperintense signals on diffusion weighted imaging(DWI).Among the 7 cases with MRI enhancement,5 cases showed significant inhomogeneous enhancement,and 2 cases showed rim enhancement."Fascial tail sign"was observed in 25 cases of NF;"double low signal sign"was seen in 16 cases of NF;"reverse target sign"was observed in 6 cases of NF lesions;peritumoral edema was seen in 9 cases;and small cystic degeneration and necrotic foci were found in 3 cases.Conclusion The imaging manifestations of NF have certain characteristics.When the tumor course is short and the tumor size is small and manifesta-tions such as"fascial tail sign""double low signal sign"and"reverse target sign"are present,the possibility of NF should be considered.