Preliminary Research Of Multi-slice Helical CT Perfusion And MR Perfusion In Soft Tissue Tumors

PURPOSE: To distinguish benign soft tissue tumors from malignant ones is often difficult in usual CT and MR imaging. With the application of MSCT(Multislice Spiral CT) and MR new techniques, perfusion weight imaging as a new functional method is very useful in nerve system. But its research in soft tissue tumors is little. We assessed diagnostic value of MSCT and MR perfusion in differential of benign and malignant soft tissue tumors.MATERIALS AND METHODS: 26 patients with soft tissue tumors were studied in MSCT perfusion and 29 patients in MR perfusion. We used the following method:1. All MSCT perfusion imaging were performed on GE lightspeed plus helical CT. First we performed tumor CT usual scan in order to localize central slices of tumors, then performed perfusion in central slices of tumors, using CT cine scan, slice thickness 10 mm/2i; with high pressure syringe, dosage 80-100ml, injection rate 3.5-4.0ml/s, scanning delay time 12-30s, scanning total time 50-70s. Scanning imaging performed perfusion analysis using CT perfusion 2 software.2.We performed tumor MR usual scan with T1WI,T2WI,STIR sequences at first, then performed perfusion in the whole tumors with high pressure syringe (dosage 0.2ml/kg, injection rate 2.5ml/s), at last performed MR usual contrast enhanced scan. Perfusion images analysis using functool software.3.The statistics methods: using 10.0 SPSS software. P<0.05 was considered significant for all test.RESULTS1) The average value of MSCT BF(Blood Flow) was 14.98±14.49 for malignant group, and 1.98±1.19 for benign group. PS (Permeability surface) was 14.64±1.89 for malignant group, and 2.40±0.38 for benign group. There was significant difference between the BF and PS values of benign and malignant tumors.2) The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of MSCT in estimating the potential malignancy of the tumors were 90.9%, 86.7%, 88.6%, 83.3%, 92.9%, respectively.3) The average value of MR BF was 0.11?.02 for malignant group, and 0.07?.01 for benign group. There was significant difference between the BF values of benign and malignant tumors.4) The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of MR in estimating the potential malignancy of the tumors were 91.7%, 88.2%, 89.6%, 84.6%, 93.8%, respectively.CONCLUSION:1. The mean BF and PS values of MSCT perfusion in malignant tumors was statistically significant. But the mean MTT and BV values had no statistically significance.2. The mean BF values of MR perfusion in malignant and benign tumors differed significantly, but BV (Blood volume) and MTT(Mean transit time) values was not statistically significant.3. Some tumors with sharply margin would think as benign ones in usual MSCT or MR imaging, but if the perfusion parameters increase apparently, it is perhaps malignant.4. MSCT and MR perfusion is very helpful with conventional scan in the differentiation of benign soft tissue tumors from malignant ones.