Differential Diagnosis Of Limb Soft Tissue Tumours Using Dynamic Contrast-enhanced Magnetic Resonance Imaging

Objective The purpose of this study was to evaluate the efficacy of the semi-quantitative and quantitative parameters of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)in differentiating benign and malignant soft tissue tumours.Materials and Methods From January 2017 to January 2019,the clinical and imaging data of patients with soft tissue tumours who were treated in our hospital were reviewed.Totally 55 cases were reviewed in this study,included 23 benign soft tissue tumours and 32 malignant soft tissue tumours.The control group consisted of normal muscle tissue at the same level of the tumour.The soft tissue tumour group included 27 men and 28 women(age range,16–85 years;median age,52 years).The MRI examinations were conducted using a 3.0T MRI scanner.Using multiple flip angle image to determine the tissue T1 relaxation times before the contrast injection.A DCE-MRI scan was conducted with the T1-weighted imaging(T1WI)volumetric interpolated breath-hold examination(VIBE)sequence.The semi-quantitative and quantitative data was analysed using Omni-K inetics software packages.The quantitative data was subjected to pharmacokinetic analysis with the Extended Tofts–Kety(ETK)model.The semi-quantitative parameters were as follows: time to peak(TTP),maximum concentration(MAX Conc.),area under curve of the time-concentration curve(AUC-TC),and maximum rise slope(MAX Slope).The quantitative parameters were as follows: volume transfer constant(Ktrans),microvascular permeability reflux constant(Kep),extravascular extracellular space distribute volume per unit tissue volume(Ve).The independent samples t test or Mann–Whitney U test was adopted to the independent data.The paired samples t test or Wilcoxon signed-rank test was adopted to the paired data.Using statistical software to determine whether the semi-quantitative and quantitative parameters of DCE-MRI have the following statistical differences,(1)benign tumours and their respective control groups,(2)malignant tumours and their respective control groups,(3)benign tumours and malignant tumours,(4)benign control groups and malignant control groups.For parameters with statistically significant differences,the receiver operating characteristic(ROC)curve was obtain.Results(1)In benign lesion groups,the values of MAX Conc.(P<0.001),AUC-TC(P<0.001),MAX Slope(P<0.001),Ktrans(P<0.001),Kep(P<0.001)and Ve(P<0.001)in benign tumours were higher than in the control groups.The values of TTP(P =0.046)in benign tumours were lower than in the control groups.The differences were statistically significant.(2)In malignant lesion groups,the values of MAX Conc.(P<0.001),AUC-TC(P<0.001),MAX Slope(P<0.001),Ktrans(P<0.001),Kep(P<0.001)and Ve(P<0.001)in malignant tumours were higher than in the control groups.The values of TTP(P<0.001)in malignant tumours were lower than in the control groups.The differences were statistically significant.(3)The values of MAX Conc.(P<0.001),AUC-TC(P<0.001),MAX Slope(P<0.001),Ktrans(P<0.001)and Kep(P<0.001)were significantly higher in malignant tumours than in benign tumours.The values of TTP(P=0.021)were lower in malignant tumours than in benign tumours.The differences were statistically significant.The values of Ve(P=0.088)were higher in malignant tumours than in benign tumours.However,the differences were not statistically significant.Based on the area under curve(AUC)of the ROC,the parameters of TTP(0.697),MAX Conc.(0.856),AUC-TC(0.833),MAX Slope(0.842),Ktrans(0.842),Kep(0.777),and Ve(0.629)had diagnostic ability.(4)The semi-quantitative parameters and quantitative parameters were not significantly different in the benign control groups and malignant control groups,TTP(P>0.05),MAX Conc.(P>0.05),AUC-TC(P>0.05),MAX Slope(P>0.05),Ktrans(P>0.05),Kep(P>0.05)and Ve(P>0.05).Conclusion The preliminary findings suggested that semi-quantitative and quantitative parameters of DC E-MRI provided the ability to differentiate between benign and malignant soft tissue tumours.The values of MAX Conc.,AUC-TC,MAX Slope,Ktrans,and Kep were higher in malignant tumours tha n in benign tumours.The values of TTP were lower in malignant tumours than in benign tumours.