Purpose: The purpose of this study was to assess the capabilities of MRI-based Node Reporting and Data System (Node-RADS) in diagnosing regional lymph node metastasis (RLNM) and to estimate its prognostic significance in patients with renal cell carcinomas (RCCs). Materials and methods: Patients with RCC who underwent nephrectomy and regional lymph node dissection between January 2010 and August 2023 were retrospectively included. Two senior radiologists scored lymph nodes in consensus using MRI-based Node-RADS. The performance of MRI-based Node-RADS for the diagnosis of RLNM was estimated using area under receiver operating characteristic (AUC) curves and compared against size criteria. Three additional readers scored all lesions to assess interobserver agreement. Progression-free survival and overall survival were estimated and compared between patients with low (1-3) and high (4-5) scores. Results: Overall, 216 patients with RCC were enrolled, including 58 with RLNM. There were 157 men and 59 women with a median age of 54 years (range: 8-83 years). Node-RADS showed larger AUC (0.93 [95 % confidence interval (CI): 0.87-0.97]) and higher specificity (96.8 % [95 % CI: 92.8-99.0]) compared to size criteria (0.88 [95 % CI: 0.83-0.94] and 87.3 % [95 % CI: 81.1-92.1], respectively) for the diagnosis of RLNM (P = 0.039 and P < 0.001, respectively). Substantial interobserver agreement in Node-RADS scoring was obtained between the three readers (weighted kappa, 0.75 [95 % CI: 0.69-0.80]). During a median follow-up of 56 months, patients with high Node-RADS score experienced poorer progression-free survival (P < 0.001) and overall survival (P < 0.001) than those with low Node-RADS score. At multivariable Cox regression analysis, Node-RADS was an independent variable associated with RCC prognosis after adjustment for confounders. Conclusions: The MRI-based Node-RADS demonstrates notable performance in detecting RLNM and showed potential prognostic significance for RCCs.

Objective: This study aimed to compare the upgrade rate and cancer detection rate between the 18F-DCFPyL PET/MRI-guided ultrasound fusion targeted biopsy (TB) and systematic biopsy in selected patients with suspected prostate cancer (the molecular imaging prostate-specific membrane antigen score of >= 2 and multiparametric MRI Prostate Imaging Reporting and Data System score of >= 4). Methods: Eighty-seven selected biopsy-naive patients were randomized into two groups: TB (n=41) and systematic biopsy (control; n=46). Patients diagnosed with clinically significant prostate cancer proceeded to radical prostatectomy. The primary outcome was the pathological upgrade rate. Secondary outcomes, including the cancer detection rate, incidence of repeat biopsy, positive surgical margin, complications, and prostate-specific antigen level at 6 weeks postoperatively, were compared between the groups using the Pearson or Fisher's exact test, as appropriate.Results: In the study, prostate cancer was ultimately detected in all patients. The TB group successfully identified all tumors, whereas five patients in the control group initially missed diagnosis. The pathological upgrade rates for the TB and control groups were 31.7 % and 56.5%, respectively. Overall, the detection rate for clinically significant prostate cancer (the International Society of Urological Pathology grade of >= 2) was significantly higher in the TB group (92.7%) compared with the control group (76.1%, p=0.035). However, no significant difference was found in the detection rate of all prostate cancer. Complications (Clavien-Dindo grade of <2) occurred in both the TB group (n=11) and control group (n=13). No statistically significant difference was observed between the groups in terms of the positive surgical margin, complications, or 6-week postoperative prostate-specific antigen level. Conclusion: The 18F-DCFPyL PET/MRI-guided ultrasound fusion TB alone was an efficient modality in diagnosing selected patients with prostate cancer. 2025 Editorial Office of Asian Journal of Urology. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/ by-nc-nd/4.0/).

To develop and validate a lesion-based grading system using clinicopathological and MRI features for predicting positive surgical margin (PSM) following robotic-assisted laparoscopic prostatectomy (RALP) among prostate cancer (PCa) patients. Consecutive MRI examinations of patients undergoing RALP for PCa were retrospectively collected from two medical institutions. Patients from center 1 undergoing RALP between January 2020 and December 2021 were included in the derivation cohort and those between January 2022 and December 2022 were allocated to the validation cohort. Patients from center 2 were assigned to the test cohort. PSM associated imaging and clinicopathological predictors were assessed. A grading system was developed through fixed effect logistic regression and classification and regression tree analysis. The area under the curve (AUC), sensitivity and specificity were calculated and compared by Delong test and McNemar test. A total 489 lesions from 396 patients were included and 82 (29.1

To evaluate the efficacy of a simple method based on qualitative MRI features for characterizing clear cell renal cell carcinoma (ccRCC) in small renal masses (SRMs). This retrospective multicenter study included pathologically confirmed SRM patients who underwent multiparametric MRI between March 2017 and November 2023 at three institutions. Univariable logistic regression and Fleiss κ coefficient were employed to determine features with significant diagnostic value and high consistency for ccRCC. A simple method was developed based on the selected features using multivariable logistic regression. The performance of the method was compared with the clear cell likelihood score (ccLS) using DeLong test and McNemar test. A total of 200 SRMs from 194 patients (116 men; median age: 54 years) were included. Intense corticomedullary enhancement, microscopic fat, and pseudocapsule were selected to construct the simple method, which considered a mass to be ccRCC if any two of the aforementioned three signs were present. Compared with ccLS, our method demonstrated similar sensitivity (0.824 versus 0.725, P = 0.227) and specificity (0.840 versus 0.860, P > 0.999). The AUC for the simple method and ccLS was 0.832 (95

Abstract Desmoplastic small round cell tumor (DSRCT) as a subtype of sarcoma is rare and aggressive. We present the case of a 23-year-old man with a histologically confirmed DSRCT who underwent 18F-PSMA PET/CT before prostate biopsy and surgical resection of the tumor. It is well known that PSMA PET has a high accuracy for detecting clinically significant prostate adenocarcinoma and is useful in guiding prostate biopsy. This case signifies DSRCT can also exhibit intermediate PSMA expression on 18F-PSMA PET/CT.

To evaluate the value of preoperative intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and conventional MRI indicators in identifying sarcomatoid dedifferentiation in renal cell carcinoma (RCC) and tumor thrombus. From September 2016 to April 2023, consecutive patients with RCC and tumor thrombus who received routine MRI examination and IVIM-DWI before radical resection were enrolled prospectively. Kaplan–Meier method with log-rank test was used to calculate and compare the survival probability. The preoperative imaging features were analyzed. Univariate and multivariable logistic regression analyses were employed to identify independent predictors of sarcomatoid dedifferentiation. The predictive ability was evaluated by receiver operating characteristic (ROC) curves. Twenty-two patients (15.3

Rationale and Objectives To improve the diagnostic recognition of papillary renal neoplasm with reverse polarity (PRNRP) through comprehensive analysis of computed tomography (CT) and magnetic resonance imaging (MRI) findings. Materials and Methods A retrospective multi-center study was conducted on patients with pathologically confirmed PRNRPs from 2019 to 2024, encompassing six institutions. Clinical and pathological data were meticulously documented. Preoperative CT (n=23) and MRI (n=9) features were independently evaluated in consensus by two genitourinary radiologists, focusing on tumor location, morphologic features, attenuation, signal intensity, and enhancement patterns. Postoperative outcomes were assessed through medical record review or telephone follow-up. Results The study cohort comprised 26 patients (mean age 62±12 years, 13 men) with 26 well-defined PRNRPs (mean diameter 2.2±1.0 cm) were included. 15 cases (58%) were situated in the right kidney, 18(69%) were exophytic, and 23(88%) were quasi-spherical. A pseudocapsule was identified in eight cases (89%) on MRI. All cases demonstrated iso- or slight hyperattenuation (43.1±13.6 HU) on non-contrast CT, hypointensity on T2-weighted imaging (T2WI), and mild diffusion restriction on diffusion-weighted imaging (DWI). All cases exhibited mild or moderate enhancement in the corticomedullary phase, followed by progressive enhancement in the nephrographic and excretory phases. Concomitant renal cysts were found in 17 cases (65%). All cases showed no evidence of recurrence or metastasis. Conclusion PRNRP typically presents as a small hypovascular renal mass, and characterized by a pseudocapsule, iso- or slight hyperattenuation on non-contrast CT, heterogeneous T2WI hypointensity, and mild diffusion restriction on DWI.

PURPOSE:This study aimed to verify the feasibility and short-term prognosis of prostatectomy without biopsy. MATERIALS AND METHODS:Patients with a rising PSA level ranging from 4 to 30 ng/mL were scheduled for multiparametric (mp) MRI and 18F-labeled prostate-specific membrane antigen (PSMA) positron emission tomography (PET). Forty-seven patients (cT2N0M0) with Prostate Imaging Reporting and Data System ≥ 4 and molecular imaging PSMA score ≥ 2 were enrolled. All candidates underwent robot-assisted laparoscopic radical prostatectomy without biopsy. Prostate cancer detection rate, index tumors localization correspondence rate, positive surgical margin, complications, postoperative hospital stay, and PSA level in a 6-week postoperative follow-up visit were collected. RESULTS:All the patients with positive mpMRI and PSMA PET were diagnosed with clinically significant prostate cancer. A total of 80 lesions were verified as cancer by pathology, of which 63 cancer lesions were clinically significant prostate cancer. Fifty-one lesions were simultaneously found by mpMRI and PSMA PET. A total of 23 lesions were invisible on either image, and all lesions were ≤ International Society of Urological Pathology 2 or ≤ 15 mm. Forty-five (95.7%) index tumors found by mpMRI combined with PSMA PET were consistent with pathology. Nine patients reported positive surgical margin. CONCLUSIONS:Biopsy-free prostatectomy is safe and feasible for patients with evaluation strictly by mpMRI combined with 18F-PSMA PET/CT.

Rationale and Objective: Accurate differentiation between benign and malignant cystic renal masses (CRMs) is challenging in clinical practice. This study aimed to develop MRI-based machine learning models for differentiating between benign and malignant CRMs and compare the best-performing model with the Bosniak classification, version 2019 (BC, version 2019). Methods: Between 2009 and 2021, consecutive surgery-proven CRM patients with renal MRI were enrolled in this multicenter study. Models were constructed to differentiate between benign and malignant CRMs using logistic regression (LR), random forest (RF), and support vector machine (SVM) algorithms, respectively. Meanwhile, two radiologists classified CRMs into I-IV categories according to the BC, version 2019 in consensus in the test set. A subgroup analysis was conducted to investigate the performance of the best- performing model in complicated CRMs (II-IV lesions in the test set). The performances of models and BC, version 2019 were evaluated using the area under the receiver operating characteristic curve (AUC). Performance was statistically compared between the best- performing model and the BC, version 2019. Results: 278 and 48 patients were assigned to the training and test sets, respectively. In the test set, the AUC and accuracy of the LR model, the RF model, the SVM model, and the BC, version 2019 were 0.884 and 75.0%, 0.907 and 83.3%, 0.814 and 72.9%, and 0.893 and 81.2%, respectively. Neither the AUC nor the accuracy of the RF model that performed best were significantly different from the BC, version 2019 (P = 0.780, P = 0.065). The RF model achieved an AUC and accuracy of 0.880 and 81.0% in complicated CRMs. Conclusions: The MRI-based RF model can accurately differentiate between benign and malignant CRMs with comparable perfor- mance to the BC, version 2019, and has good performance in complicated CRMs, which may facilitate treatment decision-making and is less affected by interobserver disagreements.

Objective: Partial or segmental inferior vena cava (IVC) resection is indicated for tumor control in patients with renal tumors invading the IVC. This study aimed to introduce a virtual vascular endoscope to assist surgeons in locating IVC invasion, formulate a surgical plan for robot-assisted IVC thrombectomy (RA-IVCT), and evaluate its potential value. Methods: The reconstruction involves building the construction of deep learning models to predict IVC invasion, which were evaluated via intraoperative findings and pathological analysis. Thirty-six patients with renal tumors and IVC thrombi who underwent RA-IVCT between June 2016 and March 2022 were included in the study. A virtual vascular endoscopy was performed based on preoperative CT findings to identify IVC invasion. Based on the extent of IVC wall invasion and the collateral situation, surgeons could decide whether to perform partial or segmental IVC resection during RA-IVCT. Results: Twenty patients were retrospectively analysed for training in virtual vascular endoscopy (the training cohort), and 16 patients were prospectively analysed to evaluate the accuracy of this technique (the validation cohort). Sixteen patients with IVC invasion underwent cavectomy, whereas six patients underwent partial IVC resection. In the validation cohort, pathological analysis confirmed the exact location of IVC invasion in eight of the nine patients, as indicated by virtual vascular endoscopy. Patients who underwent partial IVC wall resection had less lower extremity edema than those who underwent cavectomy. Conclusion: Our initial experience showed that the virtual vascular endoscopy could assist surgeons in identifying IVC invasion and creating a surgical plan for RA-IVCT.

Purpose: To determine the optimal cut-off value of Ki-67 for predicting the survival of patients with clear cell renal cell carcinoma (ccRCC) and tumor thrombus and to explore the correlation between Ki-67 expression and pathological features. Patients and Methods: We retrospectively analyzed Ki-67 immunohistochemical staining of ccRCC and tumor thrombus resected from February 2006 to February 2022. The survival rate was evaluated using the Kaplan-Meier method. The optimal cut-off value of the Ki-67 expression for predicting survival was determined by the minimum P-value method. Clinicopathological data were compared based on Ki67 status (low versus high expression). Univariate and multivariate Cox regression analysis was used to explore independent predictors. Results: A total of 202 patients (median age, 58 years [IQR, 52-65 years], 147 men) with ccRCC and tumor thrombus were included in the study. The optimal cut-off value of Ki-67 for predicting survival was 30%. 159 (78.7%) and 43 (21.3%) patients were included in the low-expression and high-expression groups. Patients with Ki-67 high expression had significantly worse recurrence-free survival (P < 0.001) and cancer-specific survival (P < 0.001). Ki-67 high expression was associated with adverse pathological features, including tumor necrosis, ISUP nuclear grade, sarcomatoid differentiation, perirenal fat invasion, renal pelvis invasion, and inferior vena cava wall invasion (all P < 0.050). Ki-67 expression >= 30% (P = 0.016), tumor side (P = 0.003), diabetes (P = 0.040), blood loss (P = 0.016), inferior vena cava wall invasion (P = 0.016), and sarcomatoid differentiation (P = 0.014) were independent predictors of cancer-specific survival. Conclusion: The optimal cut-off level of Ki-67 in predicting the prognosis of ccRCC and tumor thrombus was 30%. The high expression of Ki-67 was associated with the aggressive pathological phenotype and poor prognosis. (c) 2023 Elsevier Inc. All rights reserved.

To differentiate mixed epithelial and stromal tumor family (MESTF) of the kidney from predominantly cystic renal cell carcinoma (RCC) using the magnetic resonance imaging (MRI)-based Bosniak classification system version 2019 (v2019). The study included 36 consecutive patients with MESTF and 77 with predominantly cystic RCC who underwent preoperative renal MRI. One radiologist evaluated and documented the clinical and MRI characteristics (age, sex, laterality, R.E.N.A.L. Nephrometry Score [RNS], surgical approach, the signal intensity on T2-weighted imaging, restricted diffusion and enhancement features in corticomedullary phase). Blinded to clinical and pathological information, another two radiologists independently evaluated Bosniak category of all masses. Interobserver agreement based on Bosniak classification system v2019 was measured by the weighted Cohen/Conger’s Kappa coefficient. Furthermore, predominantly cystic RCCs and MESTFs were divided into low (categories I, II, and IIF) and high-class (categories III, and IV) tumors. The independent sample t test (Mann–Whitney U test) or Pearson Chi-square test (Fisher’s exact probability test) was utilized to compare clinical and imaging characteristics between MESTFs and predominantly cystic RCCs. The performance of the Bosniak classification system v2019 in distinguishing MESTF from predominantly cystic RCC was investigated via receiver operating characteristic curve analysis. MESTF and predominantly cystic RCC groups significantly differed in terms of age, lesion size, RNS, restricted diffusion, and obvious enhancement in corticomedullary phase, but not sex, laterality, surgical approach, and the signal intensity on T2WI. Interobserver agreement was substantially based on the Bosniak classification system v2019. There were 24 low-class tumors and 12 high-class tumors in the MESTF group. Meanwhile, 13 low-class tumors and 64 high-class tumors were observed in the predominantly cystic RCC group. The distribution of low- or high-class tumors significantly differed between the MESTF and predominantly cystic RCC groups. Bosniak classification system v2019 had excellent discrimination (cutoff value = category III), and an area under curve value was 0.81; accuracy, 80.5

Abstract Objective To assess the utility of multiparametric MRI and clinical indicators in distinguishing nuclear grade and survival of clear cell renal cell carcinoma (ccRCC) complicated with venous tumor thrombus (VTT). Materials and methods This study included 105 and 27 patients in the training and test sets, respectively. Preoperative MRI, including intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI), was performed. Renal lesions were evaluated for IVIM-DWI metrics and conventional MRI features. All the patients had postoperative histologically proven ccRCC and VTT. An expert uropathologist reviewed all specimens to confirm the nuclear grade of the World Health Organization/ International Society of Urological Pathology (WHO/ISUP) of the tumor. Univariate and multivariable logistic regression analyses were used to select the preoperative imaging features and clinical indicators. The predictive ability of the logistic regression model was assessed using receiver operating characteristic (ROC) analysis. Survival curves were plotted using the Kaplan–Meier method. Results High WHO/ISUP nuclear grade was confirmed in 69 of 105 patients (65.7%) in the training set and 19 of 27 patients (70.4%) in the test set, respectively (P = 0.647). Dp_ROI_Low, tumor size, serum albumin, platelet count, and lymphocyte count were independently related to high WHO/ISUP nuclear grade in the training set. The model identified high WHO/ISUP nuclear grade well, with an AUC of 0.817 (95% confidence interval [CI]: 0.735–0.899), a sensitivity of 70.0%, and a specificity of 77.8% in the training set. In the independent test set, the model demonstrated an AUC of 0.766 (95% CI, 0.567–0.966), a sensitivity of 79.0%, and a specificity of 75.0%. Kaplan–Meier analysis showed that the predicted high WHO/ISUP nuclear grade group had poorer progression-free survival than the low WHO/ISUP nuclear grade group in both the training and test sets (P = 0.001 and P = 0.021). Conclusions IVIM-DWI-derived parameters and clinical indicators can be used to differentiate nuclear grades and predict progression-free survival of ccRCC and VTT.

BackgroundClear cell likelihood score (ccLS) is reliable for diagnosing small renal masses (SRMs). However, the diagnostic value of Clear cell likelihood score version 1.0 (ccLS v1.0) and v2.0 for common subtypes of SRMs might be a potential score extension.PurposeTo compare the diagnostic performance and interobserver agreement of ccLS v1.0 and v2.0 for characterizing five common subtypes of SRMs.Study TypeRetrospective.Population797 patients (563 males, 234 females; mean age, 53 ± 12 years) with 867 histologically proven renal masses.Field Strength/Sequences3.0 and 1.5 T/T2 weighted imaging, T1 weighted imaging, diffusion‐weighted imaging, a dual‐echo chemical shift (in‐ and opposed‐phase) T1 weighted imaging, multiphase dynamic contrast‐enhanced imaging.AssessmentSix abdominal radiologists were trained in the ccLS algorithm and independently scored each SRM using ccLS v1.0 and v2.0, respectively. All SRMs had definite pathological results. The pooled area under curve (AUC), accuracy, sensitivity, and specificity were calculated to evaluate the diagnostic performance of ccLS v1.0 and v2.0 for characterizing common subtypes of SRMs. The average κ values were calculated to evaluate the interobserver agreement of the two scoring versions.Statistical TestsRandom‐effects logistic regression; Receiver operating characteristic analysis; DeLong test; Weighted Kappa test; Z test. The statistical significance level was P < 0.05.ResultsThe pooled AUCs of clear cell likelihood score version 2.0 (ccLS v2.0) were statistically superior to those of ccLS v1.0 for diagnosing clear cell renal cell carcinoma (ccRCC) (0.907 vs. 0.851), papillary renal cell carcinoma (pRCC) (0.926 vs. 0.888), renal oncocytoma (RO) (0.745 vs. 0.679), and angiomyolipoma without visible fat (AMLwvf) (0.826 vs. 0.766). Interobserver agreement for SRMs between ccLS v1.0 and v2.0 is comparable and was not statistically significant (P = 0.993).ConclusionThe diagnostic performance of ccLS v2.0 surpasses that of ccLS v1.0 for characterizing ccRCC, pRCC, RO, and AMLwvf. Especially, the standardized algorithm has optimal performance for ccRCC and pRCC. ccLS has potential as a supportive clinical tool.Evidence Level4.Technical EfficacyStage 2.

To explore the diagnostic characteristics of cystitis glandularis (CG) using magnetic resonance imaging (MRI). A retrospective study was conducted on pathologically confirmed patients who underwent bladder MRI examination between January 2019 and November 2023. Image analysis was jointly conducted, with emphasis on lesion location, morphology, size, signal intensity, and pattern of enhancement, by two genitourinary radiologists with 22 and 15 years of experience, respectively. A total of 27 patients with 27 lesions were included (median age 47 years, 24 males). The lesions were mostly located in the bladder trigone area (18/27). The lesions could be categorized as focal thickening (17/27), nodular (8/27), and diffuse thickening of the entire bladder (2/27) in morphological terms. On T2-weighted imaging (T2WI), 15 of 17 focal thickening lesions appeared as a slightly hyperintense thickened inner layer, with a higher signal in the center of the thickened inner layer, resembling a sandwich sign, and 6 of 8 nodular lesions were slightly hyperintense. On T1-weighted imaging (T1WI), 19 patients showed slight hypointensity. The lesions on DWI showed mainly high (5/27) and slightly high signal (21/27), with an average mean apparent diffusion coefficient (mADC) value of 2.171 ± 0.052 × 10−3mm2/s. Among the 23 patients who underwent dynamic contrast-enhanced (DCE) scanning, 18 lesions showed mild enhancement in the arterial phase (average 1.7 times comparing to unenhanced phase), and the degree of enhancement gradually increased in the venous and delayed phases (average 2.2 and 2.3 times compared to the unenhanced phase, respectively), showing a progressive enhancement pattern. On MRI, the majority of CG manifest as focal thickening or nodules in the bladder trigone area, showing slight hyperintensity on T2WI, slight hypointensity on T1WI, and a progressive enhancement pattern, without significant restriction on DWI. Focal thickening lesions may exhibit a special sandwich sign.

To evaluate whether venous tumor thrombus (VTT) consistency is a risk factor for the patient’s prognosis with renal cell carcinoma (RCC). A total of 190 RCC patients with VTT, who were treated at Department of Urology, Chinese PLA General Hospital, were retrospectively analyzed in this study. The baseline clinical characteristics, postoperative outcomes, and pathological findings were analyzed. Tumor thrombus was classified as solid and friable based on their respective characteristics. Survival curves were estimated using the Kaplan–Meier survival curve analysis, and univariable and multivariable cox proportional hazard regression models were used. Among the total 190 patients included in this study, 145 (76.3

Background Venous tumor thrombus (VTT) consistency of renal cell carcinoma (RCC) is an important consideration in nephrectomy plus thrombectomy. However, evaluation of VTT consistency through preoperative MR imaging is lacking. Purpose To evaluate VTT consistency of RCC through intravoxel incoherent motion‐diffusion weighted imaging (IVIM‐DWI) derived parameters ( D t , D p , f , and ADC) and the apparent diffusion coefficient (ADC) value. Study Type Retrospective. Population One hundred and nineteen patients (aged 55.8 ± 11.5 years, 85 male) with histologically‐proven RCC and VTT who underwent radical resection. Field Strength/Sequences 3.0‐T; two‐dimensional single‐shot diffusion‐weighted echo planar imaging sequence at 9 b ‐values (0–800 s/mm 2 ). Assessment IVIM parameters and ADC values of the primary tumor and the VTT were calculated. The VTT consistency (friable vs. solid) was determined through intraoperative findings of two urologists. The accuracy of VTT consistency classification based on the individual IVIM parameters of primary tumors and of VTT, and based on models combining parameters, was assessed. Type of operation, intra‐operative blood loss, and operation length were recorded. Statistical Tests Shapiro–Wilk test; Mann–Whitney U test; Student's t ‐test; Chi‐square test; Receiver operating characteristic (ROC) analysis. Statistical significance level was P < 0.05. Results Of the enrolled 119 patients, 33 patients (27.7%) had friable VTT. Patients with friable VTT were significantly more likely to experience open surgery, have significantly more intraoperative blood loss, and significantly longer operative duration. The area under the ROC curve (AUC) values of D t of the primary tumor and VTT in classifying VTT consistency were 0.758 (95% CI 0.671–0.832) and 0.712 (95% CI 0.622–0.792), respectively. The AUC value of the model combining D p and D t of VTT was 0.800 (95% CI 0.717–0.868). Furthermore, the AUC of the model combining D p and D t of VTT and D t of the primary tumor was 0.886 (95% CI 0.814–0.937). Conclusion IVIM‐derived parameters had the potential to predict VTT consistency of RCC. Evidence Level: 3 Technical Efficacy: Stage 2

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.

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.

Fumarate hydratasedeficient renal cell carcinoma(FH-RCC)is s a rare and highly aggressive and metastatic form of renal cell carcinoma. Clinical diagnosis is relatively challenging, and there is a lack of recognized systemic treatment options. Therefore, in clinical practice, it is necessary to have a deeper understanding of this disease and fully integrate family history, imaging findings, and pathological manifestations for clinical identification, and genetic testing shoule be conducted when necessary. Improved patient prognosis can be achieved through the selection of appropriate curative surgery or systemic treatment strategies.