Objective To analyze the difference of rotator cuff muscle group fat content by MR proton density fat fraction(PDFF)tech-nology,and to explore the correlation between these variations and the severity grading of supraspinatus tendon injury.Methods Ninety-three patients with supraspinatus tendon injury were retrospectively selected and divided into the tendinitis group(grade Ⅰ),the partial tear group(grade Ⅱ),and the complete tear group(grade Ⅲ).The fat fraction(FF)values of the three groups of rotator cuff mus-cle group were measured using the PDFF technology,and the differences in FF values among the rotator cuff muscle group in the three groups were compared.The risk factors of the grading of supraspinatus tendon injury and the correlation between FF values and the severity grading of supraspinatus tendon injury were analyzed.Results The differences in the FF values of the supraspinatus and infraspinatus muscles among the three groups were statistically significant(P＜0.01).The FF values of both the supraspinatus and infraspinatus muscles were identified as significant factors associated with the severity grading of supraspinatus tendon injury.Further-more,the FF values of the supraspinatus and infraspinatus muscles were positively correlated with the severity grading of supraspina-tus tendon injury(r=0.576,P＜0.01;r=0.510,P＜0.01).Conclusion MR PDFF technology can effectively evaluate the extent of fat infiltration in the rotator cuff muscle group after supraspinatus tendon injury.Specifically,the FF values of the supraspinatus and infraspinatus muscles serve as reliable quantitative indicators for classifying supraspinatus tendon injury.

Objective To analyze the characteristics of MR amide proton transfer(APT)imaging and enhancement signals in benign and malignant muscular soft tissue tumors and to explore the value of MR APT imaging,contrast enhancement techniques,and their combined application in the differential diagnosis of benign and malignant muscular soft tissue tumors.Methods A retrospective analysis was conducted on 34 patients with muscular soft tissue tumors confirmed by pathology,including 13 malignant and 21 benign.All patients underwent both MR with contrast enhancement and APT imaging examinations before surgery.APT values were obtained through post-processing on an image workstation.The enhancement signal characteristics and APT values were compared between benign and malignant muscular soft tissue tumors.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of the two techniques alone and in combination for differentiating between benign and malignant muscular soft tissue tumors.Results There were significant differences in enhancement signal characteristics on MR and APT values between benign and malignant muscular soft tissue tumors(P<0.05).The enhancement signal of malignant tumors was more heterogeneous,with higher enhancement degree than benign tumors;the APT value of benign tumors was(2.20±0.93)%,and the APT value of malignant tumors was(3.52±0.83)%,the ROC curve analysis determined a cutoff APT value of 2.82%for malignant tumors,with a diagnostic specificity of 90.5%and sensitivity of 76.9%.The area under the curve(AUC)for MR with contrast enhancement,APT imaging,and the combination of the two techniques were 0.694,0.857 and 0.894,respectively.No significant differences were found in the diagnostic efficacy between MR with contrast enhancement and APT imaging(Z=1.587,P=0.112 6)or between APT imaging and the combination of the two tech-niques(Z=1.217,P=0.223 4),but there was significant difference between MR with contrast enhancement and the combination of the two techniques(Z=2.428,P=0.015 2).Moreover,the combination of the two techniques showed the overall highest diag-nostic efficacy.Conclusion The combined application of MR APT imaging and contrast enhancement techniques is more beneficial for the qualitative diagnosis of muscular soft tissue tumors.

Objective To analyze the characteristics of MR amide proton transfer(APT)imaging and enhancement signals in benign and malignant muscular soft tissue tumors and to explore the value of MR APT imaging,contrast enhancement techniques,and their combined application in the differential diagnosis of benign and malignant muscular soft tissue tumors.Methods A retrospective analysis was conducted on 34 patients with muscular soft tissue tumors confirmed by pathology,including 13 malignant and 21 benign.All patients underwent both MR with contrast enhancement and APT imaging examinations before surgery.APT values were obtained through post-processing on an image workstation.The enhancement signal characteristics and APT values were compared between benign and malignant muscular soft tissue tumors.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of the two techniques alone and in combination for differentiating between benign and malignant muscular soft tissue tumors.Results There were significant differences in enhancement signal characteristics on MR and APT values between benign and malignant muscular soft tissue tumors(P<0.05).The enhancement signal of malignant tumors was more heterogeneous,with higher enhancement degree than benign tumors;the APT value of benign tumors was(2.20±0.93)%,and the APT value of malignant tumors was(3.52±0.83)%,the ROC curve analysis determined a cutoff APT value of 2.82%for malignant tumors,with a diagnostic specificity of 90.5%and sensitivity of 76.9%.The area under the curve(AUC)for MR with contrast enhancement,APT imaging,and the combination of the two techniques were 0.694,0.857 and 0.894,respectively.No significant differences were found in the diagnostic efficacy between MR with contrast enhancement and APT imaging(Z=1.587,P=0.112 6)or between APT imaging and the combination of the two tech-niques(Z=1.217,P=0.223 4),but there was significant difference between MR with contrast enhancement and the combination of the two techniques(Z=2.428,P=0.015 2).Moreover,the combination of the two techniques showed the overall highest diag-nostic efficacy.Conclusion The combined application of MR APT imaging and contrast enhancement techniques is more beneficial for the qualitative diagnosis of muscular soft tissue tumors.

Objective To analyze the difference of rotator cuff muscle group fat content by MR proton density fat fraction(PDFF)tech-nology,and to explore the correlation between these variations and the severity grading of supraspinatus tendon injury.Methods Ninety-three patients with supraspinatus tendon injury were retrospectively selected and divided into the tendinitis group(grade Ⅰ),the partial tear group(grade Ⅱ),and the complete tear group(grade Ⅲ).The fat fraction(FF)values of the three groups of rotator cuff mus-cle group were measured using the PDFF technology,and the differences in FF values among the rotator cuff muscle group in the three groups were compared.The risk factors of the grading of supraspinatus tendon injury and the correlation between FF values and the severity grading of supraspinatus tendon injury were analyzed.Results The differences in the FF values of the supraspinatus and infraspinatus muscles among the three groups were statistically significant(P＜0.01).The FF values of both the supraspinatus and infraspinatus muscles were identified as significant factors associated with the severity grading of supraspinatus tendon injury.Further-more,the FF values of the supraspinatus and infraspinatus muscles were positively correlated with the severity grading of supraspina-tus tendon injury(r=0.576,P＜0.01;r=0.510,P＜0.01).Conclusion MR PDFF technology can effectively evaluate the extent of fat infiltration in the rotator cuff muscle group after supraspinatus tendon injury.Specifically,the FF values of the supraspinatus and infraspinatus muscles serve as reliable quantitative indicators for classifying supraspinatus tendon injury.