A Comparative Study Of Soft Tissue Sarcoma IVIM?DKI And Histopathological Grading Based On MRI-Pathology

Objective:The purpose of this study is to evaluate the value of IVIM and DKI in presurgically assessing the histopathological grade of soft tissue sarcomas based on MRI-Pathology.Materials and Methods:1.case data: Eighteen patients who underwent surgical treatment of STSs in the extremities,trunk and abdominal pelvis from May 2018 to April 2019 in the Second Hospital of Da Lian Medical University and were scheduled to undergo surgery in our hospital were enrolled.There were 11 males and 7 females,aged 12-76 years,with an average age of 56 years.2.MRI inspection technology and post-processing?1?examination method:The US GE Discovery 750 3.0 T superconducting MRI scanner and the 16-channel phased array abdominal coil were used for routine MRI plain scan,IVIM,DKI and conventional contrast injection.?2?Post-processing:All the images of IVIM and DKI were sent to the post-processing software?GE ADW4.6?for analysis and processing,and ROI was drawn in the highest signal area of tumor in DWI to obtain Standard ADC,Dslow?mono?,Dfast?mono?,f?mono?,Dslow?bi?,Dfast?bi?,f?bi?,MK,MD.3.MRI-Pathology:?1?Compare the image surface with the pathological section?2?Compare ROI of the image slice with the pathological sampling spot?3?Tissue section observation4.Observation index?1?The Conventional MRI manifestations of STSs: tumor location,size,morphology,border,homogenization,signal and enhancement.?2?The IVIM parameters of STSs:Standard ADC,Dslow?mono?,Dfast?mono?,f?mono?,Dslow?bi?,Dfast?bi?,f?bi?.?3?The DKI parameters of STSs:MK,MD.?4?Histopathological manifestations of STSs: tumor morphology,structural form,interstitial properties,nuclear atypia,microscopic necrotic area,mitotic count.?5?Histopathological grading of STSs: STSs were divided into two groups according to the French Cancer Center Federation?FNCLCC?scoring system and a two-level grading system: high-level STSs?Class ?, ??and low-level STSs?Class I?.5.Statistical analysis:?1?The IVIM parameters Standard ADC value,Dslow?mono?value,Dfast?bi?value,f?bi?value and DKI parameter MK value,MD value and the difference between the high and low level comparison groups were tested by two independent samples t test.?2?The difference between the Dfast?mono?value,the f?mono?value,the Dslow?bi?value of the STSs IVIM parameters and its high and low level comparisons was determined using the Wilcoxon rank sum test.?3?Logistic regression analysis was used to evaluate the value of combined IVIM and DKI in differential diagnosis of high and low STSs.?4?The receiver operating characteristic curve?ROC?was used to evaluate the diagnostic performance of each parameter to identify high and low grade STSs.Results:1.The MRI findings of STSs?1?Conventional MRI manifestations :Position: 2 cases of buttocks,8 cases of thighs,3 cases of lower back,1 case of chest wall,1 case of abdominal cavity,1 case of hand,1 case of ankle,1 case of upper arm;Size: 6 cases of maximum diameter of tumor <5cm,?5cm 10 cases;Morphology: 5 cases of round shape,13 cases of irregularity;Boundary: 14 cases were clear,4 cases were blurred;Homogeneity: 4 cases of homogeneity,14 cases of heterogeneity;Signal: T1 WI showed equal,slightly lower signal in 18 cases;T2WI showed high signal 5 cases,13 cases of high and low mixed signals;Strengthening mode: 3 cases were obviously evenly strengthened,5 cases were obviously unevenly enhanced,3 cases were moderately unevenly strengthened,7 cases were mild uneven enhancement.?2?IVIM and DKI : DWI showed high signal in 12 cases,and slightly higher signal in 6 cases;the diffusion signal in the tissue decreased with the increase of b value.2.Pathology of STSs?1?Histopathological manifestations :Cell morphology: 3 cases of polymorphism,15 cases of fusiform or short fusiform;Structural form: 3 cases of nest,1 case of radial,5 cases of bundle,6 cases of diffuse,3 cases of lobulated;Interstitial characteristics: 3 cases,6 cases of mucus,9 cases of fiber;Nuclear atypia: mild in 4 cases,moderate in 7 cases,significant in 7 cases;Microscopic necrotic area: no necrosis in 10 cases,? 50% necrosis in 8 cases,>50% necrosis The range of 0 cases;Mitotic image count: 0-9/10 HPF 4 cases,10-19/10 HPF 14 cases,? 20/10 HPF 0cases.?2?Histopathological grading : According to the FNCLCC grading system and the2-level grading system,18 STSs were divided into two groups: 12 cases in high-grade?II,III?and 6 cases in low-grade?I?.3.Comparison of STSs IVIM and histopathological grading?1?Comparison of STSs quantitative analysis of IVIM parameters between high-level and low-level groups The difference between the Standard ADC value and the Dslow?mono?value of the IVIM parameter is significant?P<0.05?,and the high-level and low-level STSs can be identified,and the Standard ADC value and the Dslow?mono?value of the high-level STSs are lower than the low-level STSs?t=3.687?3.756,P=0.002?0.002?.The IVIM parameters Dfast?mono?value,f?mono?value,Dslow?bi?value,Dfast?bi?value,and f?bi?value were not able to identify high-level and low-level STSs?P > 0.05?.?2?Comparison of the diagnostic performance of STSs IVIM parameters Standard ADC value and Dslow?mono?value in identifying high and low grade groups The area under the curve of the IVIM-DWI parameter Standard ADC value and Dslow?mono?value of the high and low-level STSs are 0.889 and 0.917,respectively.The thresholds for identifying high and low-level STSs are 1.442 x10^-3mm²/s and 1.061x10^-3mm²/s,respectively.The sensitivity of the threshold to the identification of high and low grade STSs was 66.7%,91.7%,and the specificity was 100% and 66.7%,respectively.4.Comparison of STSs DKI and histopathological grading?1?Comparison of STSs quantitative analysis of DKI parameters between high-level and low-level groups The difference between the MK value and the MD value of the DKI parameter is significant?P<0.01?,and the high-level and low-level STSs can be identified,and the MK value of the high-level STSs is higher than that of the low-level STSs?t=-4.456,P<0.01?,and the MD value is lower than the low-level STSs?t=3.906,P=0.001?.?2?Comparison of the diagnostic performance of STSs IVIM parameters Standard ADC value and Dslow?mono?value in identifying high and low grade groups The area under the curve of the MKI value and the MD value of the DKI parameters of the high and low level STSs are 0.944 and 0.903,respectively.The thresholds for identifying the high and low level STSs are 0.642 and 1.713 um2/ms,respectively.The threshold is used to identify the high and low levels.The sensitivity of STSs was 83.3%, 100%,and the specificity was 100% and 83.3%,respectively.5.Comparison of STSs IVIM and DKI in combination with histopathological grading The area under the curve of the IVIM and DKI parameters of the high and low level STSs MK and Standard ADC,MK and Dslow?mono?,MD and Standard ADC,MD and Dslow?mono?,MK and MD,Standard ADC and Dslow?mono?are 0.944,0.958,0.903,0.944,0.944,0.931,respectively.it can be seen that IVIM-DWI and DKI parameters improve the diagnostic performance of high-and low-level STSs,and MK and Dslow?mono?has the highest diagnostic efficiency.Conclusions:1.The Standard ADC value and Dslow?mono?value of the IVIM parameters of STSs can identify high and low level STSs,the standard ADC value and Dslow?mono?value of high-level STSs are lower than low-level STSs,and the Dslow?mono?value has the best diagnostic performance.2.The MK and MD values of the DKI parameters of STSs can identify high and low level STSs.The MK value of high-level STSs is higher than that of low-level groups,and the MD value is lower than that of low-level groups,and the MK value has the best diagnostic performance.3.The IVIM and DKI parameters of STSs are improved compared with the parameters of the two separate parameters,and the diagnostic performance of MK and Dslow?mono?is the best.