Objective:To investigate the impact of the interval period between biopsy and MR examination on tumor detection and extraprostatic extension (EPE) assessment for prostate cancer (PCa) using multi-parametric MRI (mpMRI).Methods:The study was cross-sectional and retrospectively included 130 patients with PCa who underwent RP and preoperative systematic biopsies followed by mpMRI between January 2021 and December 2022 in the First Medical Center of Chinese PLA General Hospital. Patients were divided into 3 groups according to interval following biopsy (group A,<3 weeks, 31 cases; group B, 3-6 weeks, 67 cases; group C,>6 weeks, 32 cases). The percentages of hemorrhage volume in the total prostate were drawn on T 1WI and calculated. The junior, senior and expert radiologists independently localized the index lesions and calculated the accuracy for tumor detection, in addition to assessing the probabilities of EPE according to EPE grade. The correlation between the hemorrhage extent and interval was analyzed using the Spearman correlation coefficient. The accuracy for tumor detection was compared using χ2 test among groups. The diagnostic performance of the radiologists for EPE prediction was assessed using the receiver operating characteristic curve, and the differences between the corresponding area under the curve (AUC) were compared using the DeLong test. Results:The percentage of hemorrhage was correlated with the interval between biopsy and MR examination ( r=-0.325, P<0.001). The detection accuracy of junior radiologist was 83.9% (26/31), 76.1% (51/67), and 78.1% (25/32) in group A, B and C, respectively; no differences were observed in the detection accuracy among three groups ( χ2=0.76, P=0.685). The detection accuracy of senior radiologist was 83.9% (26/31), 80.6% (54/67), and 71.9% (23/32) in 3 groups with no differences ( χ2=1.53, P=0.464). The detection accuracy of expert radiologist was 80.6% (25/31), 77.6% (52/67), and 93.8% (30/32) with no differences ( χ2=3.95, P=0.139). The AUC (95% CI) for predicting EPE were 0.830 (0.652-0.940), 0.704 (0.580-0.809), 0.800 (0.621-0.920) in the group A, B and C for junior radiologist; 0.876 (0.708-0.966), 0.768 (0.659-0.863), 0.896 (0.736-0.975) for senior radiologist; and 0.866 (0.695-0.961), 0.813 (0.699-0.895), 0.852 (0.682-0.952) for expert radiologist, respectively. No differences were observed among the subgroups in each radiologist ( P>0.05). Conclusion:The interval period does not significantly affect the detection accuracy and EPE assessment of PCa using mpMRI. There is probably no necessity for prolonged intervals following systematic biopsy to preserve the clarity of MRI interpretation for PCa.

Purpose To explore the diagnostic value of prostate imaging report and data system 2.1(PI-RADS v2.1)combined with prostate-specific antigen density(PSAD)for clinically significant prostate cancer(csPCa)in prostate-specific antigen(PSA)gray area(4-10 ng/ml)based on two-center data.Materials and Methods The clinical and imaging data of patients with PSA gray zone prostate disease who underwent multi-parametric magnetic resonance imaging and all pathological data in the First Medical Center(center 1)and the Sixth Medical Center(center 2)of the Chinese PLA General Hospital from January 2017 to May 2022 were retrospectively selected and analyzed.The patients from center 1 were used as the training group(220 cases),and the patients from center 2 were used as the test group(50 cases).Logistic regression was used to determine the independent predictors of csPCa in the training group,and the diagnostic efficacy of multi-parameter combination for csPCa was analyzed,which was further verified in the test group.Results There were significant differences in prostate volume,PSAD and PI-RADS v2.1 scores between the csPCa and non-csPCa groups in the training group(Z=-6.468,6.589,75.676,all P＜0.001).Logistic regression analysis showed that PI-RADS v2.1 score and PSAD were the independent risk factors for csPCa(both P＜0.001).The area under the curve of the Logistic regression model composed of PI-RADS v2.1 and PSAD for predicting csPCa in the PSA gray zone was 0.860(95％CI 0.808-0.903)in the training group and 0.906(95％CI 0.790-0.970)in the test group,respectively.The area under the curve of Logistic regression model was significantly higher than that of PI-RADS v2.1 and PSAD,respectively,with statistically significant difference(both P＜0.05).When the PI-RADS v2.1 score was low or moderate risk and PSAD＜0.15 ng/ml2,csPCa in the training group and the test group was with low detection rate.Conclusion PI-RADS v2.1 score and PSAD may be the independent risk factors for predicting csPCa in the PSA gray zone.The combined application of the two methods is better than the single method in the diagnosis of csPCa in the PSA gray zone,with benefits for clinical biopsy decision-making.

Purpose To explore the additional value of apparent diffusion coefficient(ADC)histogram in predicting extraprostatic extension(EPE)of prostate cancer.Materials and Methods Consecutive patients undergoing multi-parameter MRI and subsequent radical prostatectomy from January 2021 to December 2022 were retrospectively included in this study.Two radiologists independently estimated EPE by using national cancer institute grading system for extraprostatic extension(EPE grade system),with disagreement resolved by discussion.Histogram metrics were derived from three-dimensional volumes of interest encompassing the entire lesion on ADC maps using FireVoxel,obtaining mean ADC,1st,5th,10th,25th,50th,75th,90th,95th and 99th ADC values.The ADC histograms between the groups with and without EPE were compared.Multivariable Logistic regression analysis was used to identify the independent predictive factors of EPE,and a combined model was developed.Receiver operator characteristic curve was used to evaluate the diagnostic performance,and the area under the curve was calculated and compared.Results Thirty-four patients(34％)had pathologic confirmed EPE after radical prostatectomy.ADC histogram parameters showed significant differences between patients with and without EPE(P＜0.05).Multivariate Logistic regression analysis revealed 99th ADC(OR=0.609,P=0.008)and EPE grade system(OR=4.158,P＜0.001)were independent predictors of EPE.For predicting EPE,the area under the curve of 99th ADC,EPE grade system and the combined model were 0.756,0.805 and 0.856,respectively.The area under the curve of 99th ADC and the EPE grade system in identifying EPE showed no significant difference.The diagnostic efficacy of combined model was significantly superior to that of 99th ADC or EPE grading system(Z=2.223,2.208,both P＜0.05).Conclusion The ADC histogram parameters demonstrate additional value for preoperative prediction of EPE.Combining the 99th ADC histogram parameter with the EPE grade system may improve the diagnostic efficacy of EPE.

Objective:To explore the value of quantitative parameters of enhanced MRI in predicting the establishment of inferior vena cava collateral circulation in patients with renal cell carcinoma and inferior vena cava tumor thrombus.Methods:Sixty-seven patients with renal cell carcinoma and inferior vena cava tumor thrombus who underwent radical resection and inferior vena cava venography in First Medical Center, PLA General Hospital from May 2006 to January 2021 were included retrospectively. According to the results of inferior vena cava venography, the patients were divided into two groups: the well-established collateral circulation group ( n=41) and the poor-established collateral circulation group ( n=26). Quantitative parameters were measured on preoperative enhanced MRI images, including tumor size, the maximum diameter of bilateral lumbar veins, the length of tumor thrombus, and the long and short diameters of tumor thrombus. Student′s t test or Mann-Whitney U test was used for comparison between the two groups. The independent risk factors related to the establishment of collateral circulation were obtained by binary logistic regression analysis and the model was established. The receiver operating characteristic curve was employed to evaluate MRI quantitative parameters and the logistic model, and the area under the curve (AUC) was compared by the DeLong test. Results:Between the well-established collateral circulation group and the poor-established collateral circulation group, the maximum diameter of the right lumbar vein, the maximum diameter of the left lumbar vein, the length of the tumor thrombus, the long diameter of the tumor thrombus, and the short diameter of the tumor thrombus were different significantly ( P<0.05). There was no significant difference in the tumor size between the two groups ( t=0.30, P=0.766). The AUC of the maximum diameters of the right lumbar veins and left lumbar veins, length of tumor thrombus, long and short diameters of tumor thrombus in predicting the collateral circulation were 0.917 (95%CI 0.824-0.971), 0.869 (95%CI 0.764-0.939), 0.756 (95%CI 0.636-0.853), 0.886 (95%CI 0.785-0.951), and 0.906 (95%CI 0.809-0.963). The AUC of the maximum diameter of the right lumbar vein and the short diameter of the tumor thrombus were larger than those of the length of the tumor thrombus, and the differences were statistically significant ( Z=2.25, 2.04, P=0.025, 0.041), but the AUC between other parameters had no significant difference ( P>0.05). The maximum diameter of the right lumbar vein (OR 24.210, 95%CI 2.845-205.998), the maximum diameter of the left lumbar vein (OR 20.973, 95%CI 2.359-186.490), and the length of the tumor thrombus (OR 23.006, 95%CI 2.952-179.309) were independent risk factors for predicting the establishment of inferior vena cava collateral circulation. The AUC of logistic model was 0.969 (95%CI 0.931-1.000). Conclusion:Quantitative parameters of tumor thrombus and lumbar vein based on enhanced MRI have a good ability in predicting the establishment of inferior vena cava collateral circulation in patients with renal cell carcinoma and inferior vena cava tumor thrombus. The maximum diameter of bilateral lumbar veins and the length of the tumor thrombus were independent risk factors for inferior vena cava collateral circulation.

Objectives:To investigate the effect of fat suppression (FS) T 2WI on the interobserver agreement and diagnostic performance of clear cell likelihood score version 2.0 (ccLS v2.0) for clear cell renal cell carcinoma (ccRCC). Methods:In this retrospective study, the MR images of 111 patients with pathologically confirmed small renal masses (SRM) from January to December 2021 were analyzed in the First Medical Centre, Chinese PLA General Hospital. Of the 111 SRM, 82 cases were ccRCC and 29 cases were non-ccRCC. Two radiologists independently assessed ccLS scores based on T 2WI signal intensity (hypointense, isointense, hyperintense) and other MRI features (ccLS-T 2WI). After a one-month interval, the ccLS scores were independently evaluated utilizing the frequency-selective saturation FS-T 2WI and other MRI features (ccLS-FS-T 2WI). Fisher′s exact test was used to compare the difference in SRM signal intensity on T 2WI and FS-T 2WI. The weighted Kappa test was performed to assess the interobserver agreement of the two radiologists, and differences in the weighted Kappa coefficients were compared using the Gwet consistency coefficient. Receiver operating characteristic curves were drawn to evaluate the diagnostic performance of ccLS-T 2WI and ccLS-FS-T 2WI in diagnosing ccRCC, and the area under the curve (AUC) was compared utilizing the DeLong test. Results:The signal intensity of 111 SRM on T 2WI and FS-T 2WI had statistically significant difference (χ 2=126.33, P<0.001), consistent in 88 cases (79.3%) and varied in 23 cases (20.7%). The weighted Kappa coefficient of ccLS-T 2WI was 0.57 (95%CI 0.45-0.69) between the two radiologists, and the weighted Kappa coefficient of ccLS-FS-T 2WI was 0.55 (95%CI 0.42-0.67), and the difference was not statistically significant ( t=-0.65, P=0.520). The AUC of ccLS-T 2WI for ccRCC diagnosis was 0.92 (95%CI 0.86-0.97), while the AUC of ccLS-FS-T 2WI for ccRCC diagnosis was 0.91 (95%CI 0.85-0.96), and the difference was not statistically significant ( Z=1.50, P=0.133). Conclusions:The interobserver agreement and diagnostic performance of ccLS v2.0 based on T 2WI and FS-T 2WI sequences for ccRCC are comparable, and FS-T 2WI is applicable for the clinical application of ccLS v2.0.

Objective:To investigate the clinical and MRI features of the mixed epithelial and stromal tumor family (MESTF) of the kidney.Methods:From January 2009 to September 2021, 42 patients with pathologically-proven MESTF from the First Medical Center of Chinese PLA General Hospital were collected in this retrospective study. Clinical information, MRI features, and pathological results were documented. According to the Bosniak classification (BC) version 2019, all MESTFs were divided into cystic MESTFs (36 cases) and solid-cystic MESTFs (6 cases). The R.E.N.A.L. nephrometry score (RNS), lesion size, laterality, location, margin, shape, growth pattern, presence of protruding into renal sinus, hemorrhage, and enhancement pattern were evaluated and documented. Based on BC versions 2005 and 2019, all the cystic MESTFs were assessed and divided into low (Ⅰ, Ⅱ, ⅡF) and high (Ⅲ, Ⅳ) grades. The independent sample t test or Mann-Whitney U test were performed to compare age, RNS, and lesion size between cystic MESTFs and solid-cystic MESTFs. Pearson χ 2 test, continuity-adjusted χ 2 test or Fisher exact probability test were utilized to evaluated the differences of clinical and MRI features and the distribution of low or high grades in two versions of BC. Results:Forty-two MESTFs were unilateral and solitary masses, 25 males and 17 females, with a mean age of (41±13) years old. Compared to solid-cystic MESTFs, cystic MESTFs were prone to demonstrate endophytic growth pattern (χ 2=17.77, P<0.001), and no significant differences in other clinical and MRI features were observed between cystic and solid-cystic MESTFs (all P>0.05). There were 7 low-grade and 29 high-grade tumors in the BC version 2005, respectively. Meanwhile, 24 low-grade and 12 high-grade tumors in the BC version 2019, respectively. The distribution of low or high-grade tumors in the two versions of BC had a statistically significant difference (χ 2=16.37, P<0.001). Conclusion:MESTFs demonstrated middle-age onset and no gender predilection. Cystic MESTFs are more likely to exhibit endophytic growth pattern with low-grade classification in BC system version 2019.

Objective:To investigate the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in the differential diagnosis of diabetic nephropathy (DN) and non-diabetic renal disease (NDRD) among patients with type 2 diabetes mellitus (T2DM).Methods:A diagnostic test. In this prospective study, patients with T2DM who underwent both IVIM-DWI and renal biopsy at the First Medical Center of Chinese PLA General Hospital between October 2017 and September 2021 were consecutively enrolled. IVIM-DWI parameters including perfusion fraction (f), pure diffusion coefficient (D), and pseudo-diffusion coefficient (D*) were measured in the renal cortex, medulla, and parenchyma. Patients were divided into the DN group and NDRD group based on the renal biopsy results. IVIM-DWI parameters, clinical information, and diabetes-related biochemical indicators between the two groups were compared using Student′s t-test or Mann-Whitney U test. The correlation of IVIM-DWI parameters with diabetic nephropathy histological scores were analyzed using Spearman′s correlation analyzes. The diagnostic efficiency of IVIM-DWI parameters for distinguishing between DN and NDRD were assessed using the receiver operating characteristic (ROC) curves. Results:A total of 27 DN patients and 23 NDRD patients were included in this study. The DN group comprised 19 male and 8 female patients, with an average age of 52±9 years. The NDRD group comprised 16 male and 7 female patients, with an average age of 49±10 years. The DN group had a higher D* value in the renal cortex and a lower f value in the renal medulla than the NDRD group (9.84×10 -3 mm 2/s vs. 7.35×10 -3 mm 2/s, Z=-3.65; 41.01% vs. 46.74%, Z=-2.29; all P<0.05). The renal medulla D* value was negatively correlated with DN grades, interstitial lesion score, and interstitial fibrosis and tubular atrophy (IFTA) score ( r=-0.571, -0.409, -0.409; all P<0.05) while the renal cortex f value was positively correlated with vascular sclerosis score ( r=0.413, P=0.032). The renal cortex D* value had the highest area under the curve (AUC) for discriminating between the DN and NDRD groups (AUC=0.802, sensitivity 91.3%, specificity 55.6%). Conclusion:IVIM-derived renal cortex D* value can be used non-invasively to differentiate DN from NDRD in patients with T2DM that can potentially facilitate individualized treatment planning for diabetic patients.

OBJECTIVE: To compare the performance of Clear Cell Likelihood Score (ccLS) v1.0 and v2.0 in diagnosing clear cell renal cell carcinoma (ccRCC) from small renal masses (SRM). METHODS: We retrospectively analyzed the clinical data and MR images of patients with pathologically confirmed solid SRM from the First Medical Center of the Chinese PLA General Hospital between January 1, 2018, and December 31, 2021, and from Beijing Friendship Hospital of Capital Medical University and Peking University First Hospital between January 1, 2019 and May 17, 2021. Six abdominal radiologists were trained for use of the ccLS algorithm and scored independently using ccLS v1.0 and ccLS v2.0. Random- effects logistic regression modeling was used to generate plot receiver operating characteristic curves (ROC) to evaluate the diagnostic performance of ccLS v1.0 and ccLS v2.0 for ccRCC, and the area under curve (AUC) of these two scoring systems were compared using the DeLong's test. Weighted Kappa test was used to evaluate the interobserver agreement of the ccLS score, and differences in the weighted Kappa coefficients was compared using the Gwet consistency coefficient. RESULTS: In total, 691 patients (491 males, 200 females; mean age, 54 ± 12 years) with 700 renal masses were included in this study. The pooled accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ccLS v1.0 for diagnosing ccRCC were 77.1%, 76.8%, 77.7%, 90.2%, and 55.7%, as compared with 80.9%, 79.3%, 85.1%, 93.4%, 60.6% with ccLS v2.0, respectively. The AUC of ccLS v2.0 was significantly higher than that of ccLS v1.0 for diagnosis of ccRCC (0.897 vs 0.859; P < 0.01). The interobserver agreement did not differ significantly between ccLS v1.0 and ccLS v2.0 (0.56 vs 0.60; P > 0.05). CONCLUSION ccLS v2.0 has better performance for diagnosing ccRCC than ccLS v1.0 and can be considered for use to assist radiologists with their routine diagnostic tasks.
Female ; Male ; Humans ; Adult ; Middle Aged ; Aged ; Carcinoma, Renal Cell/diagnosis* ; Retrospective Studies ; Kidney ; Carcinoma ; Kidney Neoplasms/diagnosis*

Objective:To investigate the value of MR subtraction images in improving the interobserver agreement for Bosniak Ⅱ, ⅡF, and Ⅲ cystic renal masses (CRMs) with Bosniak classification version 2019.Methods:From January 2009 to August 2020, 323 patients (335 CRMs) with surgical pathology results and complete preoperative MRI examination (T 2WI, T 1WI precontrast images and enhanced MRI in corticomedullary, nephrographic, and excretory phases) were retrospectively collected in the First Medical Center of PLA General Hospital. The CRMs of Bosniak Ⅱ, ⅡF, and Ⅲ were selected and classified by 2 experienced genitourinary radiologists according to the Bosniak classification version 2019. The "Subtraction" function in the American GE ADW 4.4 workstation was used to perform subtraction images reconstruction on the enhanced images in the corticomedullary, nephrographic, and excretory phases. Blinded to pathologic information, the other 2 radiologists independently classified the enrolled CRM cases with and without subtraction MR images, respectively, with an interval of 1 month. Ultimately, by using weighted Kappa value, interobserver agreement was evaluated, and the differences in weighted Kappa value were compared using the Gwet coefficient. Results:A total of 187 patients with 187 CRMs were enrolled in the study. The results of the classification of Bosniak Ⅱ, ⅡF, and Ⅲ CRMs categorized by 2 radiologists without and with subtraction images showed that 119 and 141 cases were consistent, and 68 and 46 were inconsistent, respectively. The weighted Kappa value for interobserver agreement among two radiologists without and with subtraction MR images was 0.60 (95%CI 0.53-0.68) and 0.73 (95%CI 0.66-0.80), respectively. The interobserver agreement was higher with subtraction images than that without subtraction images ( t=-2.56, P=0.011). Conclusion:According to the MRI criteria of Bosniak classification version 2019, the interobserver agreement for Bosniak Ⅱ, ⅡF, and Ⅲ CRMs could be improved using subtraction MR images, which may facilitate the popularization and application of Bosniak classification version 2019.

Objective:To analyze the MRI characteristics of surgical resected renal angiomyolipoma (AML) smaller than 4 cm.Methods:A total of 112 patients with surgical pathology confirmed renal AML of which the maximum diameter was smaller than 4 cm were analyzed retrospectively in the First Medical Centre, Chinese PLA General Hospital from January 2014 to November 2020, 5 of which were epithelioid angiomyolipoma (EAML) patients. According to the presence or absence of visible fat in lesions on MRI, the lesions were divided into AML with fat group and AML without visible fat (AML wovf) group. The MRI features were evaluated, including maximum diameter, location, growth pattern, shape, beak sign, angular interface with renal parenchyma, pseudo-capsule, hemorrhage, cystic degeneration, coagulative necrosis, flowing void in the tumor, signal intensity and homogeneity on T 2WI and diffusion weighter imaging (DWI), the peak enhanced phase. The differences of maximum diameter of AML with fat and AML wovf were analyzed using Mann-Whitney U test, and the differences of MRI features were analyzed using χ 2 test or Fisher′s exact probability test. Results:There were 123 lesions found in 112 patients, and 96 lesions contained fat and 27 lesions were AML wovf. 82 lesions showed round and round-like shapes, 112 lesions showed exophytic growth pattern, 71 lesions with peak enhancement in corticomedullary phase. And the numbers of lesions with angular interface with renal parenchyma, beak sign, cystic degeneration, pseudo-capsule, hemorrhage were 30, 49, 1, 1, 1, respectively. There was no coagulative necrosis in all lesions. Compared with AML with fat, AML wovf was single lesion. The diameters of AML with fat and AML wovf were 2.5 (1.7, 3.5) and 1.8 (1.4, 2.3) cm respectively, with statistically significant difference ( Z=-2.80, P=0.005). In the AML with fat and AML wovf, 65 and 12 cases were heterogeneous in T 2WI, 44 and 5 lesions showed beak sign, 26 and 4 lesions showed angular interface with renal parenchyma, 57 and 10 cases were heterogeneous in DWI. And there were 5 and 6 lesions showed the endophytic, 44 and 8 lesions showed partly exophytic, 47 and 13 lesions showed exophytic in patterns of tumor growth respectively. The beak sign, homogeneous in T 2WI and DWI, patterns of tumor growth showed statistical differences in AML with fat and AML wovf (all P<0.05), and there was no significant difference in other features ( P>0.05). A total of 5 EAML patients were with 8 lesions. One patient had 4 lesions with fat, other patients had single lesion in which 2 lesions with fat, 2 lesions without visible fat. One lesion without visible fat showed hemorrhage. Conclusions:Surgical resected AML smaller than 4 cm is often exophytic round and round-like, enhanced in corticomedullary phase, showing angular interface with renal parenchyma and beak sign, with rare cystic degeneration, pseudo-capsule, hemorrhage and improbable coagulation necrosis. AML wovf is single smaller lesion which often shows endophytic growth pattern, and beak sign is infrequent. EAML seems to be present in two modes, multiple lesions with fat and AML wovf with hemorrhage.