Research Of MR Diffusion Weighted Imaging And Perfusion Weighted Imaging In Soft Tissue Tumors

PURPOSE: To evaluate the diagnostic value of MR-DWI and MR-PWI in differentiation of soft tissue tumors.MATERIALS AND METHODS: 22 patients with soft tissue tumors were studied in MR-DWI and 45 patients in MR-PWI. All patients were scanned with GE Singa 1.5T MR/i by surface coil. All patients were underwent T1WI and T2WI sequences before MR-DWI and/or MR-PWI. We used the following methods: All MR-DWI were performed with SE-EPI technique, the "b" is 300 s/mm2,600 s/mm2,900 s/mm2. All MR-PWI were performed with GRE-EPI technique. Contrast-enhanced agent is Gd-DTPA. We performed MR-PWI as soon as the contrast-enhanced agent was injected by high-pressure syringe(dosage 0.2ml/kg, injection rate 2.5ml/s). We consider the most obvious enhancement of tumors as region of interested (ROI). We analyze MR-DWI and MR-PWI with the Functool 2 software to obtain apparent diffusion coefficient(ADC),blood volume(BV),mean transit time(MTT),maximal slope descending(MSD),maximal slope increasing(MSI) and time-intensity curve(TIC). We use ANOVA Variance Analysis in 10.0 SPSS software to statistics all parameters. All results were described as X±S. RESULTS:Ⅰ MR-DWI1,The mean ADC of the malignant tumors((1.86±0.04)×10-3 mm2/s) is higher than the benign tumors((1.64±0.02)×10-3 mm2/s) when b is 300 s/mm2. There is significant difference between benign and malignant tumors of ADC when b is 300 s/mm2. There are not significant difference between benign and malignant tumors of ADC when b is 600 s/mm2 and 900 s/mm2. 2,ADC become gradually descending along with b ascending. There is significant difference among different b of malignant tumors, but There is not significant difference of benign tumors.Ⅱ MR-PWI1,The mean BV of benign and malignant tumors are separately 44.04±6.18 and 178.45±20.32. The mean BF of benign and malignant tumors are separately (2.99±0.42)×10-2 and (8.67±1.06)×10-2. There is significant difference between benign and malignant tumors of BV and BF. There is not significant between benign and malignant tumors of MTT.2,TIC is descending quickly and ascending quickly in most malignant tumors, however descending slow and ascending slow in most benign tumors.3,The mean MSD of benign and malignant tumors are separately 46.67±4.18 and 65.82±5.36. There is significant difference between benign and malignant tumors of MSD. There is not significant between benign and malignant tumors of MSI.CONCLUSION:Ⅰ Conclude from researched MR-DWI in 22 patients with soft tissue tumors:1,There is significant difference between benign and malignant tumors of ADC when b is 300s/mm2. ADC is helpful to distinguish malignant tumors from benign tumors.2,ADC of soft tissue tumors become gradually descending along with b ascending. ADC of malignant tumors become descending more quickly than the benign tumors.Ⅱ Conclude from researched MR-PWI in 45 patients with soft tissue tumors:1,BV and BF of malignant tumors are higher than the benign. There is significant difference between benign and malignant tumors of BV and BF. There is not significant between benign and malignant tumors of MTT. BV and BF is helpful to distinguish malignant tumors from benign tumors.2,TIC is descending quickly and ascending quickly in most malignant tumors, however descending slow and ascending slow in most benign tumors. TIC is helpful to distinguish malignant tumors from benign tumors.3,MSD of malignant tumors are higher than the benign. There is significant difference between benign and malignant tumors of MSD. There is not significant between benign and malignant tumors of MSI. MSD is helpful to distinguish malignant tumors from benign tumors.