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 correlation between renal function and abdominal aortic hemodynamic parameters based on four-dimensional flow(4D Flow) MRI in patients with chronic kidney disease (CKD).Methods:A cross-section prospective study was conducted on 73 patients diagnosed with CKD at First People′s Hospital of Changzhou between March 2021 and May 2023, as well as 13 volunteers without kidney injury. According to the estimated glomerular filtration rate (eGFR), the subjects were divided into CKD 1-3 stage group ( n=34), CKD 4-5 stage group ( n=39), and control group ( n=13). All subjects underwent 4D Flow MRI examination of the abdominal aorta, measuring pulse wave velocity (PWV), peak velocity, and maximum wall shear stress (WSS) at the proximal plane (Plane_1) and the higher renal artery opening plane (Plane_2) of the abdominal aorta. The differences in 4D Flow MRI hemodynamic parameters among the three groups were compared using a one-way analysis of variance or the Kruskal-Wallis test. The correlation between 4D Flow MRI hemodynamic parameters and eGFR was analyzed by using the Spearman correlation coefficient. The independent influencing factors that affect eGFR were analyzed by using multivariate linear regression analysis. Results:There were significant differences in abdominal aortic PWV and maximal WSS of Plane_1 and Plane_2 among the three groups ( H=10.38, P=0.006; F=11.16, P<0.001; F=4.75, P=0.011). There were no significant differences in the peak velocity of Plane_1 and Plane_2 among the three groups (both P>0.05). Abdominal aortic PWV was negatively correlated with eGFR ( r s=-0.30, P=0.005). There was a positive correlation between the maximal WSS of Plane_1 and Plane_2 with eGFR ( r s=0.39, P<0.001; r s=0.29, P=0.006). Abdominal aortic PWV and maximal WSS of Plane_1 were independent influencing factors of eGFR (b=-4.32, P=0.018; b=132.23, P=0.004). Conclusions:There is an independent correlation between renal function and abdominal aortic hemodynamic parameters based on 4D Flow MRI in patients with CKD, and abdominal aortic PWV and maximal WSS of Plane_1 were independent influencing factors of eGFR.

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 correlation between renal function and abdominal aortic hemodynamic parameters based on four-dimensional flow(4D Flow) MRI in patients with chronic kidney disease (CKD).Methods:A cross-section prospective study was conducted on 73 patients diagnosed with CKD at First People′s Hospital of Changzhou between March 2021 and May 2023, as well as 13 volunteers without kidney injury. According to the estimated glomerular filtration rate (eGFR), the subjects were divided into CKD 1-3 stage group ( n=34), CKD 4-5 stage group ( n=39), and control group ( n=13). All subjects underwent 4D Flow MRI examination of the abdominal aorta, measuring pulse wave velocity (PWV), peak velocity, and maximum wall shear stress (WSS) at the proximal plane (Plane_1) and the higher renal artery opening plane (Plane_2) of the abdominal aorta. The differences in 4D Flow MRI hemodynamic parameters among the three groups were compared using a one-way analysis of variance or the Kruskal-Wallis test. The correlation between 4D Flow MRI hemodynamic parameters and eGFR was analyzed by using the Spearman correlation coefficient. The independent influencing factors that affect eGFR were analyzed by using multivariate linear regression analysis. Results:There were significant differences in abdominal aortic PWV and maximal WSS of Plane_1 and Plane_2 among the three groups ( H=10.38, P=0.006; F=11.16, P<0.001; F=4.75, P=0.011). There were no significant differences in the peak velocity of Plane_1 and Plane_2 among the three groups (both P>0.05). Abdominal aortic PWV was negatively correlated with eGFR ( r s=-0.30, P=0.005). There was a positive correlation between the maximal WSS of Plane_1 and Plane_2 with eGFR ( r s=0.39, P<0.001; r s=0.29, P=0.006). Abdominal aortic PWV and maximal WSS of Plane_1 were independent influencing factors of eGFR (b=-4.32, P=0.018; b=132.23, P=0.004). Conclusions:There is an independent correlation between renal function and abdominal aortic hemodynamic parameters based on 4D Flow MRI in patients with CKD, and abdominal aortic PWV and maximal WSS of Plane_1 were independent influencing factors of eGFR.

Objective:To explore the diagnostic value of contrast-enhanced mammography (CEM) and MRI in differentiating benign and malignant breast lesions based on the 2013 breast imaging reporting and data system (BI-RADS) lexicon and the supplement on CEM.Methods:The clinical and imaging data of 83 patients with breast lesions from March 2019 to April 2022 in the Third Affiliated Hospital of Soochow University were retrospectively analyzed. Totally 100 breast lesions from 83 female patients aged 28 to 78 (49±14) years, were divided into benign lesions (50 lesions) and malignant lesions (50 lesions) according to the pathological results. The t-test, χ 2 test and Fisher′s exact test were used to compare the differences of clinical and imaging features between benign and malignant lesions, and these imaging features which had statistical differences were established CEM and MRI models by multivariate logistic regression analysis respectively. The receiver operating characteristic curves and the area under the curve (AUC) were used to assess the diagnostic efficacy of two models in differentiating benign and malignant breast lesions. Using the DeLong test compared the AUC. Results:Multivariate logistic regression analysis showed that associated features (OR=9.075,95%CI 1.430-57.570, P=0.019), lesion conspicuity (OR=6.180,95%CI 2.608-14.646, P<0.001), mass margin (OR=2.193,95%CI 1.405-3.422, P=0.001) and calcification distribution (OR=2.147,95%CI 1.157-3.986, P=0.015) were independent predictors of differentiating benign and malignant breast lesions in CEM, and then the predictive model of CEM was constructed. Time-signal intensity curve (OR=9.230, 95%CI 3.178-26.805, P<0.001), associated features (OR=5.289,95%CI 1.343-20.831, P=0.017) and mass margin (OR=2.192,95%CI 1.336-3.597, P=0.002) were independent predictors of differentiating benign and malignant breast lesions in MRI, and the predictive model of MRI was constructed. The AUC of CEM and MRI models for differentiating benign and malignant breast lesions were 0.947 and 0.930 respectively, and two models were no significant difference ( Z=0.68, P=0.494). Conclusion:The diagnostic efficacy of CEM and MRI in differentiating benign and malignant breast lesions is comparable based on the 2013 BI-RADS lexicon and the supplement on CEM.

Objective:To explore the value of susceptibility-weighted imaging (SWI) in quantitative evaluation of iron load in diabetic kidneys.Methods:Thirty two healthy New Zealand white rabbits were randomly divided into diabetic group (DM, n = 20) and control group (NC, n = 12). DM model was established by injecting 5% alloxan solution (100 ml/kg) through ear vein. 12 rats were finally enrolled into the group. NC group was injected with the same dose of normal saline. DM group and NC group were intramuscularly injected with 60 mg/kg iron dextran. The left kidney was scanned by MRI immediately after iron injection (0 weeks) and 12 weeks after feeding. The left kidney was killed after 12 weeks of scanning. The left kidney was examined by Prussian blue staining and atomic absorption spectrophotometer. The value of SWI in quantitative evaluation of renal iron content was evaluated by using the iron content measured by atomic absorption spectrophotometer as the gold standard. On SWI phase diagram, the region of interest (ROI) was manually drawn along the renal cortical vagal area, and the measured phase values were converted into angular radians. Mann Whitney U test was used to compare the blood glucose value and the angle radian value at 0 week and 12 week between the two groups; independent sample t test was used to compare the difference of iron content between the two groups; nonparametric Wilcoxon signed rank test was used to compare the difference of angle radian between DM group and NC group at 0 and 12 weeks; Spearman correlation analysis was used to study the correlation between angle radian value and atomic absorption spectrophotometer results. Results:The blood glucose level in DM group [28.0 (10.6) mmol/L] was significantly higher than that in NC Group [6.5 (1.9) mmol/L], and the difference was statistically significant (U = 0, P<0.001). At week 0, there was no significant difference between DM group [-0.04 (-0.02)] and NC Group [-0.02 (0.06)] in angle radian value (U=105.50, P>0.05); at 12 weeks, the angle radian value of DM group [0.22 (0.17)] was higher than that of NC Group [0.17 (0.05)], the difference was statistically significant (U=35.50, P<0.05). The angle radian of DM group and NC group at 12 weeks were higher than that of 0 weeks, and the differences were statistically significant ( P<0.05). Prussian blue staining showed that iron was mainly deposited in renal cortex, and the blue staining in DM group was more obvious than that in NC group. The signal intensity of renal cortex on SWI images in DM group was significantly lower than that in 0 week group at 12 weeks, and slightly decreased in NC group. The iron content of DM group and NC group were (171.39±20.13) mg/kg and (116.21±28.90) mg/kg, respectively, and the difference was statistically significant ( t=5.428, P<0.001). Spearman correlation analysis showed that the angle radian was positively correlated with iron content ( r=0.67, P<0.001). Conclusions:Diabetic kidneys have more iron deposits than normal kidneys. As a non-invasive, simple and convenient examination technique, SWI has the potential to quantitatively evaluate the iron load of diabetic kidneys.

Objective: To detect the values of CT texture features in the preoperative prediction of Fuhrman grade of clear cell renal cell carcinoma (ccRCC). Methods: The CT data of 206 patients with ccRCC admitted to the Third Affiliated Hospital of Soochow University from January 2011 to December 2016 were retrospectively analyzed, and the ccRCC cases were graded using Fuhrman grading system, including 38 cases of Grade Ⅰ, 107 cases of Grade Ⅱ, 50 cases of Grade Ⅲ and 11 cases of Grade Ⅳ. All subjects undergone plain and enhancement CT scans. There were two methods used for the extraction of texture features, including histogram (2 features: Kurtosis and Skewness) and gray-level co-occurrence matrix (6 features: Contrast, Correlation, Energy, Entropy, Homogeneity and Variance). Each texture feature during Grade Ⅰ to Ⅳ was compared using a one-way analysis of variance following the log-ratio transformation, and a Newman-Keuls test was performed for all pairwise comparisons. An independent sample t test was used to find the differences of each texture feature between low (Grade Ⅰ+Ⅱ) and high grade (Grade Ⅲ+Ⅳ) ccRCC. A Spearman Rank test was performed to quantify the correlation of each texture feature with Fuhrman grade in ccRCC. Receiver operating characteristic curve (ROC) was employed to compare the diagnostic performance of the texture features to differentiate the low grade from high grade ccRCC. Results: Six texture features, including Contrast, Correlation, Entropy, Homogeneity, Variance and Kurtosis, were different during Grade Ⅰ to Ⅳ (all P<0.05) with the exception of the two features of Energy and Skewness (all P>0.05). Furthermore, five textures, such as Correlation, Entropy, Homogeneity, Variance and Kurtosis, were not significantly different between Grade Ⅲ and Ⅳ ccRCC. There was no clinical application value for the features of Correlation, Energy, Entropy, Variance and Skewness with the absolute coefficients of<0.3, in contrast, the correlation coefficients were -0.54, 0.39 and 0.32 for the features of Contrast, Homogeneity and Kurtosis, respectively (all P<0.05). Compared with that in the low grade ccRCC, the values of Contrast and Variance reduced in the high grade ccRCC (all P<0.05), while the values of Kurtosis, Correlation and Homogeneity increased significantly in the high grade ccRCC (all P<0.05), and no difference was found for the features of Skewness, Energy and Entropy between the low and high grade ccRCC (all P>0.05). When those features were used to differentiate the high from low grade ccRCC, the Contrast exhibited the biggest area under ROC of 0.806 (P<0.05), followed by the Correlation of 0.641, Homogeneity of 0.687, Kurtosis of 0.668 and Variance of 0.659. Conclusion CT texture features can preoperatively predict the Fuhrman grade of ccRCC, and the Contrast will likely be the potential imaging biomarker for the clinical application.

Objective To explore the value of susceptibility-weighted imaging (SWI) for the assessment of chronic renal injury. Methods Thirty-nine patients with clinical diagnosis of chronic renal injury (RI group) who underwent routine renal MRI and SWI examination were retrospectively analyzed. They were divided into mild injured group (15 cases) and moderate to severe injured group (24 cases) by estimated glomerular filtration rate (eGFR). At the same time, 17 volunteers without chronic renal injury who had normal serum creatinine (Scr) and blood urea nitrogen were recruited as control group. All subjects underwent routine renal MRI and SWI examination. The ratios of cortex to medulla were measured and calculated in both kidneys' magnitude image and susceptibility weighted image, which were indicated as C/MMAG and C/MSWI. Independent sample t test was used to compare the differences of C/MMAG and C/MSWI between control group and RI group, and paired sample t test was used to compare the differences betweenC/MMAG and C/MSWI in each group. One-way ANOVA was used to compare the difference of C/MMAG and C/MSWI between the control group and the different RI groups. ROC was employed to assess the diagnostic efficacy of C/MMAG and C/MSWI in renal injury. Pearson linear correlation analysis was used to evaluate the correlation between C/MMAG, C/MSWI and eGFR, Scr in patients with renal injury. Results The C/MMAG and C/MSWI in the RI group were 1.101±0.039 and 1.071±0.046, respectively. C/MSWI was obviously lower than C/MMAG, and the difference was statistically significant (t=5.056, P<0.01). There was no significant difference between C/MMAG and C/MSWI in the control group (P>0.05). The C/MMAG and C/MSWI in the RI group were obviously lower than those in the control group, and the difference was statistically significant (t=4.564, 6.122;P<0.01).The C/MMAG and C/MSWI in the mild injured group and the moderate to severe injured group were significantly lower than those in the control group, the difference was statistically significant (P<0.05). While the differences of those between mild injured group and moderate to severe injured group showed no statistical significance (P>0.05). The area under ROC of C/MMAG and C/MSWI in diagnosis of renal injury were 0.853 and 0.952, respectively. C/MMAG was positively correlated with eGFR (r=0.460,P<0.01). Conclusions Susceptibility-weighted imaging can be used to assess chronic renal injury. Although it cannot reflect the degree of renal function damage, it has some value in the early diagnosis of mild renal injury.

OBJECTIVE: To assess the feasibility of susceptibility-weighted imaging (SWI) while monitoring changes in renal oxygenation level after water loading. MATERIALS AND METHODS: Thirty-two volunteers (age, 28.0 +/- 2.2 years) were enrolled in this study. SWI and multi-echo gradient echo sequence-based T2* mapping were used to cover the kidney before and after water loading. Cortical and medullary parameters were measured using small regions of interest, and their relative changes due to water loading were calculated based on baseline and post-water loading data. An intraclass correlation coefficient analysis was used to assess inter-observer reliability of each parameter. A receiver operating characteristic curve analysis was conducted to compare the performance of the two methods for detecting renal oxygenation changes due to water loading. RESULTS: Both medullary phase and medullary T2* values increased after water loading (p < 0.001), although poor correlations were found between the phase changes and the T2* changes (p > 0.05). Interobserver reliability was excellent for the T2* values, good for SWI cortical phase values, and moderate for the SWI medullary phase values. The area under receiver operating characteristic curve of the SWI medullary phase values was 0.85 and was not different from the medullary T2* value (0.84). CONCLUSION: Susceptibility-weighted imaging enabled monitoring changes in the oxygenation level in the medulla after water loading, and may allow comparable feasibility to detect renal oxygenation level changes due to water loading compared with that of T2* mapping.
Adult ; Female ; Humans ; Kidney/*metabolism ; Magnetic Resonance Imaging/*methods ; Male ; Oxygen/blood/*metabolism ; ROC Curve ; Reproducibility of Results ; Water/*administration & dosage ; Young Adult

Objective To investigate the imaging characteristics of mucinous tubular and spindle cell carcinoma of the kindey (MTSCC-K).Methods Five cases of pathologically confirmed MTSCC-K were analyzed retrospectively.All patients underwent CT scanning,and 4 cases underwent conventional MR and diffusion weighted imaging (DWI) scanning.MR enhancement ratio for the tumor was calculated according to MR signal intensity of pre-and post-contrast in tumor and apparent diffusion coefficient (ADC) values of tumor and normal renal cortical.Results Two case located in the right kindey,and 3 cases located in the left kindey.The maximum diameter of lesions ranged from 3.2 cm to 7.1 cm.Five cases showed nearly round shape with clear borderline.Pseudocapsule was found in 4 cases,3 cases had necrosis and cystic,and 1 case had calcification.There were no hemorrhage,fat and invasion of adjacent tissue.Isodensity or hypodense tumors were found on plain CT.Isointense or hyperintense tumors were found on plain T1WI,while isointense or mixed-signal tumors were found on plain T2WI.Slightly homogeneous or heterogeneous enhancement was observed on dynamic enhanced CT or MR,and the solid component of tumors showed hyperintense on DWI and hypointense on ADC.The mean CT value of tumor at the plain,cortical and nephrographic phase was 32.6 HU,46.5 HU and 66.5 HU,respectively.The mean ADC value of tumor and normal renal cortical was 1.23 × 10-3 mm2/s and 2.31 × 10-3 mm2/s,respectively.The mean MR percentage of enhancement value of tumor was 32.7％ and 104.9％,respectively.Conclusions The imaging characteristics of MTSCC-K include nearly round shape,pseudocapsule,clear borderline,necrosis,cystic and calcification.There is no invasion of adjacent tissue and seldom malignant appearances.Isodensity or hypodense can be observed on plain CT,isointense or hyperintense on plain T1WI,and a mild continuously enhancement on dynamic enhanced scanning.