Objective:To investigate the associations between MRI texture features and genetic mutations in clear cell renal cell carcinoma (ccRCC) and non-ccRCC (n-ccRCC).Methods:This was a cross-section study. A retrospective review was performed on 31 patients (ccRCC group 19 cases and n-ccRCC group 12 cases) diagnosed with renal cell carcinomas and underwent targeted sequencing between April 2011 and December 2021 in the Third Affiliated Hospital of Soochow University. All the patients underwent MRI examinations within two weeks before partial or radical nephrectomy. Texture features were extracted from T 1WI, T 2WI, Dixon-MRI, cortical-medulla phase (CMP), nephrographic phase (NGP), and delayed phase (DEP) images. MRI texture features with the highest value for distinguishing ccRCC from n-ccRCC were selected for subsequent analysis. The next-generation high-throughput sequencing technology was employed to analyze gene mutations in renal tumors. The correlation between mutation genes and texture features in ccRCC and n-ccRCC was analyzed using Spearman correlation coefficient. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation analysis was performed. Results:A total of 8 MRI texture features were selected. In the ccRCC group, PTEN mutation was correlated with DEP_InverseDifferenceMoment_angle0_offset7 ( r=-0.58, P=0.009). In the non-ccRCC group, SETD2 mutation was correlated with CM_Phase_InverseDifferenceMoment_AllDirection_offset1 and Dixon_W_InverseDifferenceMoment_AllDirection_offset7 ( r=0.58, 0.63, P=0.048, 0.027), PBRM1 mutation was correlated with DE_Phase_InverseDifferenceMoment_angle0_offset7 and DE_Phase_HaraVariance ( r=0.61, -0.60, P=0.034, 0.039), and FAT1 mutation was correlated with DE_Phase_HaraVariance and NG_Phase_Inertia_angle135_offset4 ( r=0.58, 0.58, P=0.047, 0.047). The KEGG pathway annotation analysis showed that the mechanisms of the mutation genes that correlated with MRI texture features in the ccRCC group were related to the p53 signaling pathway, inositol phosphate metabolism, central carbon metabolism in cancer, EGFR tyrosine kinase inhibitor resistance, PD-L1 expression and PD-1 checkpoint pathway in cancer, and phosphatidylinositol signaling system. The mutation genes correlated with MRI texture features in the non-ccRCC group were mainly associated with lysine degradation. Conclusion:The associations are found between MRI texture features and underlying genetic mutations of ccRCC and n-ccRCC. These mutation genes have completely different enrichment pathways.

Objective:To explore the value of four-dimensional flow (4D Flow) MRI in evaluating hemodynamic changes of transplant renal artery stenosis (TRAS).Methods:The study was a cross-sectional study. A retrospective analysis of 67 patients after renal transplantation was performed in Third Affiliated Hospital of Soochow University from January 2021 to October 2022. All patients were examined with non-contrast enhanced magnetic resonance angiography (NCE-MRA) and 4D Flow MRI. After NCE-MRA assessment, the patients were divided into a non stenosis group (39 cases), non-obvious stenosis group (stenosis degree<50%, 13 cases) and obvious stenosis group (stenosis degree≥50%, 15 cases). The 4D Flow MRI data were analyzed using the post-processing software CVI42 (Canada) to measure hemodynamic parameters of the transplanted renal artery in the non-stenosis group, as well as the proximal, central, and distal regions of the stenosis in the non-obvious stenosis group and obvious stenosis group. The parameters included net flow rate, maximum flow rate, average velocity, peak velocity, average wall shear stress, and maximum wall shear stress. One way analysis of variance and least significant difference (LSD) were used to test the differences of hemodynamic parameters among the three groups and between the proximal, central and distal regions of the stenosis. Pearson correlation coefficient was used to evaluate the correlation between hemodynamic parameters of transplant renal artery and estimated glomerular filtration rate (eGFR).Results:The net flow, maximum flow and average velocity at the proximal region of stenosis in the group with obvious stenosis of transplanted renal artery were significantly lower than those in the non-stenosis group and the non-obvious stenosis group (all P<0.05). The net flow and maximum flow at the distal region of stenosis in both obvious stenosis group and non-obvious stenosis group were lower than those in non-stenosis group, and the differences were statistically significant (both P<0.001). The mean velocity and peak velocity at the distal region of stenosis in the obvious stenosis group were higher than those in the non-stenosis group, and the differences were statistically significant (both P<0.05). The maximum and average wall shear stress at the distal region of stenosis in the obvious stenosis group were lower than those in the non-stenosis group and the non-obvious stenosis group, and the differences were statistically significant (both P<0.05). The net flow and maximum flow in the center region of stenosis were lower than those in the proximal region of stenosis, and the differences were statistically significant (both P<0.05). The peak velocity in the center region and distal region of stenosis was higher than those in the proximal region of stenosis, and the difference was statistically significant (both P<0.05). There was a positive correlation between the net flow and eGFR at the TRAS patients proximal, center, and distal stenosis ( r=0.270, 0.260, 0.320, respectively, P=0.044, 0.041, 0.036, respectively). There was a positive correlation between the maximum flow and eGFR at the TRAS patients proximal, center, and distal stenosis ( r=0.306, 0.276, 0.269, respectively, P=0.037, 0.041, 0.043, respectively). Conclusion:After TRAS, there is a significant change in blood flow status. The 4D Flow MRI can provide quantitative hemodynamic parameters to reflect the hemodynamic changes of TRAS.

Objective:To investigate the associations between MRI texture features and genetic mutations in clear cell renal cell carcinoma (ccRCC) and non-ccRCC (n-ccRCC).Methods:This was a cross-section study. A retrospective review was performed on 31 patients (ccRCC group 19 cases and n-ccRCC group 12 cases) diagnosed with renal cell carcinomas and underwent targeted sequencing between April 2011 and December 2021 in the Third Affiliated Hospital of Soochow University. All the patients underwent MRI examinations within two weeks before partial or radical nephrectomy. Texture features were extracted from T 1WI, T 2WI, Dixon-MRI, cortical-medulla phase (CMP), nephrographic phase (NGP), and delayed phase (DEP) images. MRI texture features with the highest value for distinguishing ccRCC from n-ccRCC were selected for subsequent analysis. The next-generation high-throughput sequencing technology was employed to analyze gene mutations in renal tumors. The correlation between mutation genes and texture features in ccRCC and n-ccRCC was analyzed using Spearman correlation coefficient. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation analysis was performed. Results:A total of 8 MRI texture features were selected. In the ccRCC group, PTEN mutation was correlated with DEP_InverseDifferenceMoment_angle0_offset7 ( r=-0.58, P=0.009). In the non-ccRCC group, SETD2 mutation was correlated with CM_Phase_InverseDifferenceMoment_AllDirection_offset1 and Dixon_W_InverseDifferenceMoment_AllDirection_offset7 ( r=0.58, 0.63, P=0.048, 0.027), PBRM1 mutation was correlated with DE_Phase_InverseDifferenceMoment_angle0_offset7 and DE_Phase_HaraVariance ( r=0.61, -0.60, P=0.034, 0.039), and FAT1 mutation was correlated with DE_Phase_HaraVariance and NG_Phase_Inertia_angle135_offset4 ( r=0.58, 0.58, P=0.047, 0.047). The KEGG pathway annotation analysis showed that the mechanisms of the mutation genes that correlated with MRI texture features in the ccRCC group were related to the p53 signaling pathway, inositol phosphate metabolism, central carbon metabolism in cancer, EGFR tyrosine kinase inhibitor resistance, PD-L1 expression and PD-1 checkpoint pathway in cancer, and phosphatidylinositol signaling system. The mutation genes correlated with MRI texture features in the non-ccRCC group were mainly associated with lysine degradation. Conclusion:The associations are found between MRI texture features and underlying genetic mutations of ccRCC and n-ccRCC. These mutation genes have completely different enrichment pathways.

Objective:To explore the value of four-dimensional flow (4D Flow) MRI in evaluating hemodynamic changes of transplant renal artery stenosis (TRAS).Methods:The study was a cross-sectional study. A retrospective analysis of 67 patients after renal transplantation was performed in Third Affiliated Hospital of Soochow University from January 2021 to October 2022. All patients were examined with non-contrast enhanced magnetic resonance angiography (NCE-MRA) and 4D Flow MRI. After NCE-MRA assessment, the patients were divided into a non stenosis group (39 cases), non-obvious stenosis group (stenosis degree<50%, 13 cases) and obvious stenosis group (stenosis degree≥50%, 15 cases). The 4D Flow MRI data were analyzed using the post-processing software CVI42 (Canada) to measure hemodynamic parameters of the transplanted renal artery in the non-stenosis group, as well as the proximal, central, and distal regions of the stenosis in the non-obvious stenosis group and obvious stenosis group. The parameters included net flow rate, maximum flow rate, average velocity, peak velocity, average wall shear stress, and maximum wall shear stress. One way analysis of variance and least significant difference (LSD) were used to test the differences of hemodynamic parameters among the three groups and between the proximal, central and distal regions of the stenosis. Pearson correlation coefficient was used to evaluate the correlation between hemodynamic parameters of transplant renal artery and estimated glomerular filtration rate (eGFR).Results:The net flow, maximum flow and average velocity at the proximal region of stenosis in the group with obvious stenosis of transplanted renal artery were significantly lower than those in the non-stenosis group and the non-obvious stenosis group (all P<0.05). The net flow and maximum flow at the distal region of stenosis in both obvious stenosis group and non-obvious stenosis group were lower than those in non-stenosis group, and the differences were statistically significant (both P<0.001). The mean velocity and peak velocity at the distal region of stenosis in the obvious stenosis group were higher than those in the non-stenosis group, and the differences were statistically significant (both P<0.05). The maximum and average wall shear stress at the distal region of stenosis in the obvious stenosis group were lower than those in the non-stenosis group and the non-obvious stenosis group, and the differences were statistically significant (both P<0.05). The net flow and maximum flow in the center region of stenosis were lower than those in the proximal region of stenosis, and the differences were statistically significant (both P<0.05). The peak velocity in the center region and distal region of stenosis was higher than those in the proximal region of stenosis, and the difference was statistically significant (both P<0.05). There was a positive correlation between the net flow and eGFR at the TRAS patients proximal, center, and distal stenosis ( r=0.270, 0.260, 0.320, respectively, P=0.044, 0.041, 0.036, respectively). There was a positive correlation between the maximum flow and eGFR at the TRAS patients proximal, center, and distal stenosis ( r=0.306, 0.276, 0.269, respectively, P=0.037, 0.041, 0.043, respectively). Conclusion:After TRAS, there is a significant change in blood flow status. The 4D Flow MRI can provide quantitative hemodynamic parameters to reflect the hemodynamic changes of TRAS.

Objective:To explore the feasibility of chemical exchange saturation transfer (CEST) imaging at 3.0 T MRI in quantifying renal redox metabolism in vitro models and experimental animals.Methods:Redox metabolites in vitro models with physiological concentrations were prepared, including reduced metabolites (glutamate, alanine, glutathione) and oxidized metabolites (2-ketoglutarate, pyruvate, glutathione disulfide, ammonium hydroxide). CEST examinations were performed at 3.0 T MRI. The imaging parameters were as follows: CEST images with different saturation pulse intensity (B 1) (1, 2, 3, 4 μT) and a fixed radio frequency (RF) duration of 2 000 ms; CEST images with different RF durations (1 500 and 2 000 ms) were acquired with a fixed B 1 value of 2 μT to obtain the optimal scanning parameters. CEST examinations with optimized parameters were performed on the left kidneys of seven healthy rabbits, and the differences in magnetic resonance ratio asymmetry (MTR asym) between rabbit renal cortex and outer medulla were measured. A paired t-test was used to compare the differences. Results:The optimal B 1 for CEST examination of redox metabolites was 2 μT, and the optimal RF duration was 2 000 ms. The MTR asym peaks of glutathione disulfide, glutathione, glutamic acid, and alanine were at 3.75, 3.5, 3, and 1.5 ppm, respectively. The MTR asym peaks of pyruvate, 2-ketoglutarate, and ammonium hydroxide were at 1 ppm. The MTR asym peak values of reduced metabolites were higher than those of oxidized metabolites. When the B 1 value was 2 μT and the RF duration was 2 000 ms, the MTR asym signal of the renal cortex was (2.60±1.10) %, (2.86±1.32) %, (3.04±1.06) %, and (2.98±0.91) % at 1, 3, 3.5, and 3.75 ppm, respectively. The MTR asym signal of the outer medulla was (1.00±0.56) %, (2.43±0.94) %, (2.29±0.88) % and (1.98±0.58) %, respectively. The MTR asym signal of the renal cortex was higher than that of the outer medulla, and the differences were statistically significant ( t=3.04, P=0.023; t=2.56, P=0.043; t=3.50, P=0.013; t=3.45, P=0.014). Conclusion:CEST imaging at 3.0 T MRI can be used to quantitatively evaluate redox metabolism of healthy rabbit kidneys in vitro model and normal experimental rabbits.

Objective:To investigate the feasibility of 3.0 T glutamate chemical exchange saturation transfer (GluCEST) imaging in evaluating renal redox metabolism in renal ischemia-reperfusion injury (IRI).Methods:Rabbits in the IRI group ( n=56) underwent surgery by clamping the left renal artery for 45 min and then releasing to establish IRI. Rabbits in the sham group ( n=8) underwent the same operation without clamping the left renal artery. GluCEST MRI was performed before and at 1 h, 12 h, 1 day, 3 days, 7 days, and 14 days after the operations, with eight rabbits in the IRI group sacrificed immediately after each scanning and eight in the sham group sacrificed at 14 days after scanning. The left kidneys were removed for histopathological examination and reactive oxygen species (ROS) fluorescence staining. Differences in the magnetic resonance ratio asymmetry (MTR asym) of the renal cortex and outer medulla among different groups were compared. Correlations between the MTR asym and ROS were analyzed. Results:The MTR asym of the renal cortex in the sham and IRI subgroups were higher than that of the outer medulla ( t=8.16, P<0.001; t=4.78, P=0.002; t=4.94, P=0.002; t=5.76, P=0.001, t=6.68, P<0.001; t=6.40, P<0.001; t=5.16, P=0.001; t=3.30, P=0.013). The MTR asym of the renal cortex and outer medulla in the IRI-1h, IRI-12h, IRI-1d, IRI-3d, IRI-7d, and IRI-14d groups were lower than in the sham and IRI-pre groups (all P<0.05). The MTR asym of the renal cortex and outer medulla in the IRI-1h group were lower than in the IRI-12h, IRI-1d, IRI-3d, IRI-7d, and IRI-14d groups (all P<0.05). The MTR asym of the renal cortex in the IRI-12h group was lower than in the IRI-7d and IRI-14d groups (1.84%±0.09% vs.2.42%±0.19%, 2.41%±0.31%, all P<0.05). The MTR asym of the renal cortex in the IRI-1d group was lower than in the IRI-7d group (1.99%±0.17% vs. 2.42%±0.19%, P=0.008). The MTR asym of the outer medulla in the IRI-12h group was lower than in the IRI-3d, IRI-7d, and IRI-14d groups (1.32%±0.27% vs. 1.79%±0.31%, 1.98%±0.18%, 1.66%±0.40%, respectively, all P<0.05]. The MTR asym of the outer medulla in the IRI-7d group was higher than in the IRI-1d and IRI-14d groups (1.98%±0.18% vs. 1.52%±0.31%, 1.66%±0.40%, all P<0.05). The MTR asym of the renal cortex and outer medulla had a strong negative correlation with the mean fluorescence intensity of ROS ( ρ=-0.889, P<0.001; ρ=-0.784, P<0.001). Conclusion:3.0 T GluCEST imaging can indirectly reflect the changes of renal redox metabolism in renal IRI.

Objective:To compare the value of 3 methods (threshold method, visual method and CT method) based on 18F-FDG PET-CT for qualitative diagnosis of solitary pulmonary nodules (SPN). Methods:The clinical characteristics, pathological results, CT signs and maximum standardized uptake value (SUV max) of 226 SPN patients who underwent 18F-FDG PET-CT and met lung imaging reporting and data system (Lung-RADS1.1) grading criteria grade 2-4 in Shanxi Province Cancer Hospital from January 2015 to January 2019 were retrospectively analyzed, and the diagnostic efficacy of threshold method (according to SUV max), visual method [according to the degree of fluorodeoxyglucose (FDG) uptake in the mediastinum or liver blood pool] and CT method (according to Lung-RADS1.1 grading criteria) for SPN were compared by using receiver operating characteristic (ROC) curve. The highest diagnostic accuracy of CT method and the highest diagnostic accuracy of threshold method and visual method were combined as PET-CT comprehensive diagnosis method, and the diagnostic efficiency of which was compared with the other methods. Results:Among the 226 patients with SPN, 174 cases were malignant and 52 cases were benign in pathology. ROC curve analysis showed that the area under the curve (AUC) of CT method 2 (defined Lung-RADS1.1 grade 4A and below as benign, grade 4B and above as malignant) in CT methods for qualitative diagnosis of SPN was 0.622, the sensitivity was 87.93%, and the accuracy was 76.11%, the diagnostic efficiency was higher than method 2. The AUC of the threshold method 1 (defined solid nodules that SUV max≥2.5 and ground-glass nodules that SUV max≥1.14 as malignant, the others as benign) in threshold methods for qualitative diagnosis of SPN was 0.675, the sensitivity was 85.06%, and the accuracy was 76.99%, the diagnostic efficiency was higher than other methods in the threshold methods and visual methods. The AUC of PET-CT comprehensive diagnosis method (combination of CT method 2 and threshold method 1) for qualitative diagnosis of SPN was 0.652, the sensitivity was 97.70%, and the accuracy was 82.74%, the diagnostic efficiency was higher than other methods. Conclusions:There is no significant difference among threshold method, visual method and CT method based on 18F-FDG PET-CT in qualitative diagnosis of SPN. The diagnostic efficiency of combining CT method with threshold method is significantly improved.

Objective:To investigate the value of multimodal MRI radiomics in the preoperative prediction of Fuhrman nuclear grade of clear cell renal cell carcinoma (ccRCC).Methods:A total of 129 patients with ccRCC confirmed by pathology from April 2011 to April 2021 in Third Affiliated Hospital of Soochow University were collected, and the imaging and clinicopathological data were retrospectively analyzed. All patients were divided into training set ( n=90) and validation set ( n=39) at the ratio of 7∶3 using random indicator method. According to the postoperative pathological results, Fuhrman grades Ⅰ and Ⅱ were included in the low grade group (96 cases, 65 cases in the training set and 31 cases in the validation set), and Fuhrman grades Ⅲ and Ⅳ were included in the high grade group (33 cases, 25 cases in the training set and 8 cases in the validation set). Two radiologists manually delineated regions of interest (ROI) on T 1WI, T 2WI, Dixon-water, Dixon-fat, susceptibility weighted imaging (SWI), blood oxygen level dependent (BOLD) images, and 396 texture features were extracted from each ROI. In the training set, intra-class correlation coefficient, Mann-Whitney U test, minimum redundancy maximum relevance and least absolute shrinkage and selection operator method were used to reduce the dimension of features to obtain the best texture features. The logistic regression was used to develop the multimodal radiomics model, and the receiver operating characteristic (ROC) curve was used to evaluate the effectiveness of the model in identifying high and low-grade ccRCC in training set and validation set. Results:Four SWI, one T 2WI and one BOLD texture features were selected for modeling. The areas under the ROC curve (95%CI) of the multimodal radiomics model for identifying high and low grade ccRCC in the training and validation sets were 0.859 (0.770-0.923) and 0.883 (0.740-0.964), with the specificity at 95.4% and 87.1%, the sensitivity at 68.0% and 87.5%, the accuracy at 87.8% and 87.2%, respectively. Conclusion:The multimodal MRI radiomics model based on T 2WI, SWI and BOLD images has high effectiveness in preoperative predicting Fuhrman nuclear grade of ccRCC.

To investigate the clinical characteristics of metastatic hormone sensitive prostate cancer and explore the strategy of combination of new endocrine drugs.In April 2019, an 69-year-old man was admitted to the First People’s hospital of Changzhou with "gross hematuria" . Physical examination showed prostatic hyperplasia with an unsmooth hard surface. CT showed a mass in bladder and possible metastasis in right lung. Diagnostic TUR-Bt pathology showed prostatic acinar adenocarcinoma, and PET-CT showed malignant lesion of prostate with bladder invasion, multiple pelvic lymph node metastasis and lung metastasis. The diagnosis of mHSPC with lymphatic and lung metastasis was considered. The patient was treated with bicalutamide and then switched to goserelin plus acetate abiraterone with prednisone. Total prostate specific antigen (tPSA) decreased to 0.705 ng/ml after 1 month of ADT+ AAP treatment, and decreased to 0.007 ng/ml after 4 months, and then maintained at 0.003 ng/ml until January 2021. Serum testosterone decreased to 0ng/dl and maintained the whole follow-up period. After 3 months of treatment, the pulmonary metastasis was not obvious. Till the last follow-up at January 2021, the patient reported good quality of life with no serious adverse events. The efficacy of ADT combined with acetate abiraterone in the treatment of mHSPC with lung cancer was significant.

Objective:To explore the relationship between MRI texture features with the histopathology in early renal ischemia-reperfusion injury (IRI).Methods:Forty-eight healthy New Zealand rabbits were randomly divided into the IRI group ( n=40) and the sham group ( n=8). As for the IRI group, rabbits underwent the left kidney surgery by clamping the left renal artery for 60 mins and then releasing the clamp to establish renal IRI model. The rabbits in the sham group underwent the same operation, but without clamping the left renal artery. MR examination were performed before and at 1 h, 12 h, 24 h, and 48 h after the operations. As for the IR group, eight rabbits were randomly sacrificed at each time point immediately after MR exam. The eight rabbits in the sham group were sacrificed after MR exam at 48 h after the operation. The left kidney was harvested for histopathological examination. The single item score of the histopathological features, the microvessel density (MVD), and the pathological total score were calculated. Differences in the single item score of the histopathological features, MVD, and the pathological total score among IRI group with different time points and sham group were determined using the Kruskal-Wallis test. MRI texture features of the left kidney were extracted. Multiple dimensionality reduction for MRI texture features were performed, and the features associated with the pathological total score were selected. The relationship between MRI texture features with the single item score of the histopathological features and MVD was assessed by Pearson correlation coefficients. Results:There were significant differences in renal tubular brush border destruction, renal tubular epithelial edema, necrosis, cast, interstitial inflammatory cell infiltration, MVD, and the pathological total score in IRI group among the different time points (all P<0.05). T 2WI_S (3, -3) InvDfMom had the highest correlation with renal tubular brush border destruction, renal tubular epithelial edema, necrosis, and cast ( r=0.56, -0.58, 0.62, 0.69, all P<0.01). BOLD_S (4, -4) Correlat had the highest correlation with interstitial inflammatory cell infiltration ( r=0.63, P<0.01). SWI_S (4, 4) DifEntrp had the highest correlation with MVD ( r=0.61, P<0.01). Conclusion:MRI texture analysis can provide valuable information for evaluating early renal IRI.