Study On Cartilage Injury And Osteoarthritis Of Knee Joint Based On IVIM And MRI Radiomics

PART 1 The value of intravoxel incoherent motion imaging of knee subchondral bone in the diagnosis of cartilage injury in knee osteoarthritisObjective: To explore the value of quantitative parameters of intravoxel incoherent motion(IVIM)imaging in the diagnosis of cartilage injury in knee osteoarthritis(KOA).Methods: From January 2021 to October 2022,70 patients with KOA diagnosed by clinic and knee arthroscopy in Yijishan Hospital of Wannan Medical College were collected as the observation group,and 30 healthy volunteers matched with sex and age as the control group.All patients were scanned by IVIM within 2 weeks before operation,and the regions of interest(ROI)were delineated at the subchondral bone of the medial and medial condyle of femur and the subchondral bone of the medial and medial tibial plateau,and the quantitative parameters: true diffusion coefficient(D),false diffusion coefficient(D *)and perfusion fraction(f)were obtained.One-way ANOVA or Kruskal-Wallis H test was used to compare the differences of quantitative parameters among different arthroscopic outerbridge cartilage grades.LSD test or post-hoc test was used for pairwise comparison,and spearman correlation analysis was used to evaluate the correlation between subchondral bone D,D*,f values and outerbridge cartilage grade.Results: There were significant differences in D value,D * value and f value of knee subchondral bone between the control group and the observation group(outerbridgeⅠ ～ Ⅳ).The results of pairwise comparison between the two groups showed that there were significant differences in D values between the control group and outerbridge grades Ⅱ,Ⅲ and Ⅳ(P = 0.011,0.000,0.000,respectively,P = 0.029),and between the control group and outerbridge grade Ⅰ,and between the control group and outerbridge grade Ⅰ,the difference was statistically significant,and the difference was statistically significant.There was significant difference in f value between control group and outerbridge grade Ⅳ.There was significant difference in f value between outerbridge grade Ⅰ and grade Ⅲ,Ⅳ in Paddy 0.006,P = 0.037 and0.007,respectively.There was a moderate positive correlation between knee subchondral bone D value and outerbridge grade(spearman correlation coefficient =0.674,P = 0.000),and a weak positive correlation between f value and outerbridge grade(spearman correlation coefficient = 0.328,P = 0.001).Conclusions: 1.The quantitative parameters of IVIM imaging of knee subchondral bone can grade the severity of knee cartilage injury and contribute to the early diagnosis of KOA patients.2.There is a moderate positive correlation between D value and outerbridge cartilage grade,which is expected to become a new biological index to help diagnose KOA.PART 2 The value of conventional magnetic resonance imaging Radiomics in the diagnosis of cartilage injury in the early stage of knee osteoarthritisObjective: To explore the value of conventional magnetic resonance imaging(MRI)radiomics in the diagnosis of cartilage injury in the early stage of knee osteoarthritis.Methods: 50 patients with early cartilage injury of knee osteoarthritis diagnosed by clinical and knee arthroscopy examination in Yijishan Hospital of Wannan Medical College from January 2021 to October 2022 were collected as the observation group,and 30 healthy volunteers matched with sex and age as the control group.All subjects underwent routine MRI scan of knee joint.According to the proportion of 7:3,all patients were randomly divided into training set(n = 56)and verification set(n = 24).Using ITK-SNAP software,the regions of interest(ROI)were delineated along the edge of articular cartilage on all aspects of sagittal T1 WI and sagittal fat suppression PDWI images,and three-dimensional ROI was obtained and imported into AK software to extract texture features.maximum relevance minimum redundancy(m RMR)and least absolute shrinkage and selection operator(LASSO)were used to reduce the dimension of texture features.the radiomics tags of sagittal T1 WI,sagittal fat suppression PDWI and joint sequence were established,and the score(rad-score)was calculated.100 th retention cross-validation(LGOCV)was used to verify the reliability of the model.Multivariate logistic regression analysis was used to establish a routine model for the variables with statistically significant differences in clinical features,and a comprehensive diagnostic model was established based on the conventional model and the radiomics model with the highest diagnostic efficiency.The diagnostic efficacy of the model was evaluated by receiver operating characteristic(ROC)curve.Results: In the training set,the BMI of the conventional model was an independent factor for the diagnosis of early degenerative cartilage injury of the knee joint(OR=1.338,95%CI was 1.055 to 1.696).The area under the curve(AUC)of the conventional model in the training set and verification set was 0.78,0.76 respectively.After dimension reduction,10,9 and 10 optimal features were obtained from sagittal T1 WI,sagittal fat suppression PDWI and texture features extracted from joint sequence images.the diagnostic efficiency of joint sequence radiomics model was higher than that of each single sequence radiomics model.The AUC of joint sequence radiomics model in training set and verification set were 0.86 and 0.91 respectively.In the training set,the joint sequence rad-score of the comprehensive diagnosis model(OR=2.275,95%CI is 1.350 to 3.834)was an independent factor,and the AUC of the comprehensive diagnosis model in the training set and verification set was 0.90 and 0.91 respectively.The comprehensive diagnostic model is superior to the conventional model in the diagnosis of early degenerative cartilage injury of the knee joint(P = 0.0076).Conclusions: 1.The conventional model based on clinical characteristics has a certain value in the diagnosis of cartilage injury in the early stage of knee osteoarthritis,in which BMI is an independent factor and an important variable.2.The radiomics model based on each single sequence and combined sequence of MRI has high value in the diagnosis of cartilage injury in the early stage of knee osteoarthritis,in which the diagnostic efficiency of combined sequence radiomics model is the highest,and the diagnostic efficiency of radiomics model is better than that of conventional model.3.The comprehensive diagnostic model is the best in the diagnosis of cartilage injury in the early stage of knee osteoarthritis,which is obviously better than the conventional model,in which the combined sequence radiomics tag is an independent factor.Radiomics is of high value in the diagnosis of early cartilage injury in knee osteoarthritis.