RESUMO
【Objective】 To develop a prognosis model based on CT images using radiomics method for patients with osteonecrosis of the femoral head (ONFH) and to investigate the additional prediction value of the imaging features of the contralateral normal femoral head regions for the prognosis prediction. 【Methods】 A total of 51 patients were included in this retrospective study. All the patients had preoperative CT images. For each patient, two regions of interest (ROIs) were involved, including the osteonecrosis region and the contralateral normal femoral head region. A total of 968 radiomics features were extracted for each patient. We made both the univariate and multivariable analyses. Three models were developed based on the features of osteonecrosis region, contralateral normal femoral head region, and both regions. The 10 times of repeated random experiments were used for model construction and validation. The average performance of the 10 times of experiments was reported as the results. 【Results】 For the features of osteonecrosis region, 37 features showed significant predictive value, with the mean AUC value of 0.708 2±0.029 9. The AUC of the constructed prediction model was 0.911 0±0.029 4 and 0.688 6±0.089 3 for the training set and validation set, respectively. For the features of contralateral normal femoral head region, 14 features showed significant predictive value, with the mean AUC value of 0.703 6±0.006 9. The AUC value of the constructed model for the training set and validation set was 0.867 2±0.039 5 and 0.669 0±0.072 6, respectively. For the models developed based on combined features, the AUC value was higher than that of the models developed based on osteonecrosis region features (training set: 0.935 8±0.016 6 vs. validation set: 0.737 9±0.090 8). 【Conclusion】 We developed a novel CT images-based radiomics method to predict postoperative prognosis in patients with ONFH. Furthermore, the features of contralateral normal femoral head region has additional prediction value. Combining the imaging features of osteonecrosis region and contralateral normal femoral head region can obtain more accurate prediction of prognosis in patients with ONFH.
RESUMO
Objective To evaluate the stability of U6 and let-7a as internal reference genes of miRNAs in RTqPCR by using femoral head samples of cartilage tissue from inbred DA rats.Methods Total RNA was extracted from femoral head cartilage tissues of female DA rats at three different time points,i.e.at birth (D0),ablactation (D21) and maturation (D42).The expressions of different miRNAs (miR-1,-25,-26a,-140,-146a,-150,-181a,-195,-223 and-337) were detected by RT-qPCR using U6 or let-7a as the internal reference.The two sets of miR expression were compared with the results from Solexa sequencing in our pioneer work to evaluate the stability of the two internal references.Results The relative values of U6 (P =0.045) and let-7a (P =0.021 5) revealed significant difference in the D42 sample.Both in U6 and let-7a systems,miR-26a,-140,-223,and-337 showed a similar tendency in expression and quantification but miR-1 and-146a did not have significant differences.miR-25,-150,-181a and-195 differed significantly (P＜0.05).Comparison of absolute quantification results between the two generations' sequencing showed that let-7a is more stable than U6.Conclusion Let-7a is more suitable to be used as the internal reference gene in RT-qPCR for miRNAs in cartilage tissue.