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Urothelial carcinoma can arise from any portion of the urothelial lining extending from the kidneys to the urethra, with morphologic subtypes including papillary, polypoid, infiltrative, and ulcerative growth patterns. Imaging plays a crucial role in detecting upper and lower urinary tract tumors and in differentiating them from other benign mimics. Computed tomographic urography (CTU) is the imaging modality of choice for the diagnosis of urothelial carcinoma as well as for noninvasive surveillance following treatment. CTU allows evaluation of recurrent primary tumor while evaluating for metastatic disease in a single study., Competing Interests: Disclosures A. Kambadakone received research grants from GE Healthcare, PanCAN, Bayer—Research Grants, and working as consultant to Bayer (Consultant; not relevant to this study). None of the other authors have any relevant financial relationships or conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Although kidney diseases have a high prevalence, initial recognition and diagnosis of renal disease are complicated in avian medicine., Objective: The aim of this study is to assess the intraosseous excretory urography (IOEU) in order to introduce a new method for evaluation of kidney's function in broilers as a primary model of birds., Methods: A total of 10 male broiler chickens at the age of 20 days were included and evaluated with plain and serial post-contrast radiography and computed tomography (CT) scan to check the time and concentration of the contrast media (CM) passage from the kidney. In the next step, after the nephropathy induction with gentamicin, plain and serial post-contrast radiography and CT scan were repeated. After the necropsy, kidney samples were sent for histopathology evaluation, and statistical analysis of data obtained from image analysis was conducted., Results: After nephropathy induction, all of the chickens exhibited increase in kidney size and in histopathological evaluation, all the samples (30 of 30) showed severe tubular necrosis and mild glomerulopathy. In the IOEU, the average time to create the maximum concentration of CM, the average time to decrease the CM concentration from the kidney and the time of the complete clearance of CM indicated a significant incensement after nephropathy compared to the time before it., Conclusion: Intraosseous excretory urography (IOEU) is a safe contrast imaging modality and can be useful in the assessment of the urinary system in chickens to check the changes in kidney size and function., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

This study aimed to develop a deep-learning (DL) based method for three-dimensional (3D) segmentation of the upper urinary tract (UUT), including ureter and renal pelvis, on non-enhanced computed tomography (NECT) scans. A total of 150 NECT scans with normal appearance of the left UUT were chosen for this study. The dataset was divided into training (n = 130) and validation sets (n = 20). The test set contained 29 randomly chosen cases with computed tomography urography (CTU) and NECT scans, all with normal appearance of the left UUT. An experienced radiologist marked out the left renal pelvis and ureter on each scan. Two types of frameworks (entire and sectional) with three types of DL models (basic UNet, UNet3 + and ViT-UNet) were developed, and evaluated. The sectional framework with basic UNet model achieved the highest mean precision (85.5%) and mean recall (71.9%) on the test set compared to all other tested methods. Compared with CTU scans, this method had higher axial UUT recall than CTU (82.5% vs 69.1%, P < 0.01). This method achieved similar or better visualization of UUT than CTU in many cases, however, in some cases, it exhibited a non-ignorable false-positive rate. The proposed DL method demonstrates promising potential in automated 3D UUT segmentation on NECT scans. The proposed DL models could remarkably improve the efficiency of UUT reconstruction, and have the potential to save many patients from invasive examinations such as CTU. DL models could also serve as a valuable complement to CTU., (© 2024. The Author(s).)

Background: Accurate measurement of ureteral diameters plays a pivotal role in diagnosing and monitoring urinary tract obstruction (UTO). While three-dimensional magnetic resonance urography (3D MRU) represents a significant advancement in imaging, the traditional manual methods for assessing ureteral diameters are characterized by labor-intensive procedures and inherent variability. In the realm of medical image analysis, deep learning has led to a paradigm shift, yet the development of a comprehensive automated tool for the precise segmentation and measurement of ureters in MR images is an unaddressed challenge., Purpose: The ureter was quantitatively measured on 3D MRU images using a deep learning model., Methods: A retrospective cohort of 445 3D MRU scans (443 patients, 52 ± 18 years; 217 female patients) was collected and split into training, validation, and internal testing cohorts. A 3D V-Net model was trained for urinary tract segmentation, and a post-processing algorithm was developed for ureteral measurements. The accuracy of the segmentation was evaluated using the Dice similarity coefficient (DSC) and volume intraclass correlation coefficient (ICC), with ground truth segmentations provided by experienced radiologists. The external cohort comprised 50 scans (50 patients, 55 ± 21 years; 30 female patients), and the model-predicted ureteral diameter measurements were compared with manual measurements to assess system performance. The various diameter parameters of ureter among the different measurement methods (ground truth, auto-segmentation with automatic diameter extraction, and manual segmentation with automatic diameter extraction) were assessed with Friedman tests and post hoc Dunn test. The effectiveness of the UTO diagnosis was assessed by receiver operating characteristic (ROC) curves and their respective areas under the curve (AUC) between different methods., Results: In both the internal test and external cohorts, the mean DSC values for bilateral ureters exceeded 0.70. The ICCs for the bilateral ureter volume obtained by comparing the model and manual segmentation were all greater than 0.96 (p  <  0.05), except for the right ureter in the internal test cohort, for which the ICC was 0.773 (p  <  0.05). The mean DSCs for interobserver and intraobserver reliability were all above 0.97. The maximum diameter of the ureter exhibited no statistically significant differences either in the dilated (p = 0.08) or in the non-dilated (p = 0.32) ureters across the three measurement methods. The AUCs of ground truth, auto-segmentation with automatic diameter extraction, and manual segmentation with automatic diameter extraction in diagnosing UTO were 0.988 (95% CI: 0.934, 1.000), 0.961 (95% CI: 0.893, 0.991), and 0.979 (95% CI: 0.919, 0.998), respectively. There was no statistical difference between AUCs of the different methods (p > 0.05)., Conclusion: The proposed deep learning model and post-processing algorithm provide an effective means for the quantitative evaluation of urinary diseases using 3D MRU images., (© 2024 American Association of Physicists in Medicine.)

Introduction: Children with spina bifida (SB) undergo a videourodynamic study (VUDS) or urodynamic study and voiding cystourethrogram (VCUG). A standardized protocol for imaging during a pediatric VUDS has not been established. Our aim is to quantify radiation exposure and establish a baseline for children with spina bifida (SB) undergoing VUDS in current practice at our institution., Methods: This is a retrospective study from 2013 to 2020 of consecutive pediatric SB patients undergoing VUDS by a single provider. Patients were categorized into three groups based on age; group 1 (0-2 YR), group 2 (2-10 YR), group 3 (>10 YR). Radiation data was reported as mean air kerma (AK), dose area product (DAP) and exposure time (seconds). Effective dose (ED) was calculated based on radiation quantity (Air Kerma, AK) and organ sensitivity. The lifetime attributable risk (LAR) was calculated based on AK and a risk coefficient. Data points calculated for patients undergoing VUDS were then compared to age matched institutional VCUG data in the same age groups., Results: 398 patients undergoing VUDS met inclusion criteria and 262 independent patients underwent VCUG. ED increased with age in both VUDS and VCUG. All VCUG groups were found to have a higher ED than VUDS. The LAR for VUDS groups 1-3 was 0.001, 0.002, and 0.006, respectively. Reported in percentages, there is a 0.1%, 0.2%, and 0.6% chance, respectively, of age groups 1, 2 and 3 developing cancer as a result of the radiation exposure from a VUDS., Discussion: Our study found that ED was low across all age groups for VUDS, comparing favorably to the VCUG groups. VCUG was selected as a benchmark comparison for its diagnostic similarities and, at times, overlapping indications. Few studies have described ED with respect to VUDS or extrapolate the ED of VUDS into LAR in the pediatric population. We recognize that we have not determined the true ED of the gonads and bladder, rather we have overestimated, as the data is based on an international reference point proximal to the exposed individual. However, LAR was calculated for each age group and revealed that patients are at a negligible increased risk of developing malignancy secondary to exposure compared to the general population., Conclusion: Our current practice for pediatric VUDS has exhibited consistently low radiation exposure amongst all age groups. Moving forward, we have the foundation and flexibility to create an imaging protocol for pediatric VUDS, while taking more calculated steps toward incorporating ALARA, as low as reasonably achievable, principles. A protocol adhering to the ALARA principle could provide consistency across institutions and aid in multi-institutional studies., Competing Interests: Conflicts of interest None., (Copyright © 2024 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Purpose: To assess the proportion of upper tract urothelial carcinomas (UTUC) that are evident without the excretory phase at CT urography (CTU), and the proportion of potentially avoidable radiation., Methods: UTUCs diagnosed between January 2008-December 2017 were retrospectively identified from a population-based cancer registry. For each patient, US, non-urographic CT, and MRI exams were assessed for a primary mass and secondary imaging findings (hydronephrosis, urinary tract thickening, luminal distention, fat stranding, and lymphadenopathy/metastatic disease). CTUs were assessed for primary and secondary findings, and whether the tumor was evident as a filling defect on excretory phase. The dose-length product (DLP) of potentially avoidable excretory phases was calculated as a fraction of total DLP., Results: 288 patients (mean age, 72±11 years, 165 males) and 545 imaging examinations were included. Of 192 patients imaged with 370 non-urographic CTs, a primary mass was evident in 154 (80.2%), secondary findings were evident in 172 (89.6%), and primary or secondary findings were evident in 179 (93.2%). Of 175 CTUs, primary and secondary findings were evident in 157 (89.7%) and 166 (94.9%) examinations, respectively, and primary or secondary findings were evident in 170/175 (97.1%). 131/175 (74.9%) UTUCs were evident as a filling defect, including the 5/175 (2.9%) UTUCs without primary or secondary findings. Of 144 CTUs with available DLP data, the proportion of potentially avoidable radiation was 103.7/235.8 (44.0%) Gy⋅cm., Conclusion: In our population, almost all UTUCs were evident via primary or secondary imaging findings without requiring the excretory phase. These results support streamlining protocols and pathways., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: To compare various lower pole pelvicalyceal anatomical factors of stone bearing kidney with contralateral normal kidneys and determine whether these factors predispose to stone formation in one kidney., Methods: A descriptive study was done with Computed Tomography of 54 patients with solitary lower pole calculus in one kidney and normal contralateral kidney were included. Various lower pole pelvicalyceal anatomical factors like infundibulopelvic angle, infundibular width, infundibular length and calyceopelvic height of both stone bearing and contralateral kidneys were measured and compared for any differences Results: The mean infundibular width was 5.4±1.9mm on stone bearing kidneys and 5.2±2.05mm on contralateral normal kidneys. The mean infundibular length was 18.9±4.4mm on stone bearing kidneys and 18.8±3.9mm on contralateral normal kidneys. The mean infundibulopelvic angle was 47.9±10.8° on stone bearing kidneys and 47.6±11.2° on contralateral kidneys. The mean calyceopelvic height was 15.7±4.6mm on stone bearing kidneys and 15.5±3.9mm (range 7.5to 23.1mm) on contralateral kidneys. There were no statistically significant differences between stone bearing and contralateral normal kidneys in respect to these pelvicalyceal anatomical factors., Conclusions: In this study, we found no significant difference in lower pole pelvicalyceal anatomical factors between stone bearing kidneys and contralateral normal kidneys and therefore these factors do not seem to have significant role in stone formation in one kidney compared with the other.

Objectives: Upper tract urothelial carcinoma (UTUC) is a rare, aggressive lesion, with early detection a key to its management. This study aimed to utilise computed tomographic urogram data to develop machine learning models for predicting tumour grading and staging in upper urothelial tract carcinoma patients and to compare these predictions with histopathological diagnosis used as reference standards., Methods: Protocol-based computed tomographic urogram data from 106 patients were obtained and visualised in 3D. Digital segmentation of the tumours was conducted by extracting textural radiomics features. They were further classified using 11 predictive models. The predicted grades and stages were compared to the histopathology of radical nephroureterectomy specimens., Results: Classifier models worked well in mining the radiomics data and delivered satisfactory predictive machine learning models. The multilayer panel showed 84% sensitivity and 93% specificity while predicting UTUC grades. The Logistic Regression model showed a sensitivity of 83% and a specificity of 76% while staging. Similarly, other classifier algorithms [e.g. Support Vector classifier (SVC)] provided a highly accurate prediction while grading UTUC compared to clinical features alone or ureteroscopic biopsy histopathology., Conclusion: Data mining tools could handle medical imaging datasets from small (<2 cm) tumours for UTUC. The radiomics-based machine learning algorithms provide a potential tool to model tumour grading and staging with implications for clinical practice and the upgradation of current paradigms in cancer diagnostics., Clinical Relevance: Machine learning based on radiomics features can predict upper tract urothelial cancer grading and staging with significant improvement over ureteroscopic histopathology. The study showcased the prowess of such emerging tools in the set objectives with implications towards virtual biopsy., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: To evaluate whether artificial intelligence (AI) based automatic image analysis utilising convolutional neural networks (CNNs) can be used to evaluate computed tomography urography (CTU) for the presence of urinary bladder cancer (UBC) in patients with macroscopic hematuria., Methods: Our study included patients who had undergone evaluation for macroscopic hematuria. A CNN-based AI model was trained and validated on the CTUs included in the study on a dedicated research platform (Recomia.org). Sensitivity and specificity were calculated to assess the performance of the AI model. Cystoscopy findings were used as the reference method., Results: The training cohort comprised a total of 530 patients. Following the optimisation process, we developed the last version of our AI model. Subsequently, we utilised the model in the validation cohort which included an additional 400 patients (including 239 patients with UBC). The AI model had a sensitivity of 0.83 (95% confidence intervals [CI], 0.76-0.89), specificity of 0.76 (95% CI 0.67-0.84), and a negative predictive value (NPV) of 0.97 (95% CI 0.95-0.98). The majority of tumours in the false negative group (n = 24) were solitary (67%) and smaller than 1 cm (50%), with the majority of patients having cTaG1-2 (71%)., Conclusions: We developed and tested an AI model for automatic image analysis of CTUs to detect UBC in patients with macroscopic hematuria. This model showed promising results with a high detection rate and excessive NPV. Further developments could lead to a decreased need for invasive investigations and prioritising patients with serious tumours.

Background: Split kidney function (SKF) is critical for treatment decision in pediatric patients with hydronephrosis and is commonly measured using renal scintigraphy (RS). Non-contrast-enhanced magnetic resonance urography (NCE-MRU) is increasingly used in clinical practice. This study aimed to investigate the feasibility of using NCE-MRU as an alternative to estimate SKF in pediatric patients with hydronephrosis, compared to RS., Methods: Seventy-five pediatric patients with hydronephrosis were included in this retrospective study. All patients underwent NCE-MRU and RS within 2 weeks. Kidney parenchyma volume (KPV) and texture analysis parameters were obtained from T2-weighted (T2WI) in NCE-MRU. The calculated split KPV (SKPV) percent and texture analysis parameters percent of left kidney were compared with the RS-determined SKF., Results: SKPV showed a significant positive correlation with SKF (r = 0.88, p < 0.001), while inhomogeneity was negatively correlated with SKF (r =  - 0.68, p < 0.001). The uncorrected and corrected prediction models of SKF were established using simple and multiple linear regression. Bland-Altman plots demonstrated good agreement of both predictive models. The residual sum of squares of the corrected prediction model was lower than that of the uncorrected model (0.283 vs. 0.314) but not statistically significant (p = 0.662). Subgroup analysis based on different MR machines showed correlation coefficients of 0.85, 0.95, and 0.94 between SKF and SKPV for three different scanners, respectively (p < 0.05 for all)., Conclusions: NCE-MRU can be used as an alternative method for estimating SKF in pediatric patients with hydronephrosis when comparing with RS. Specifically, SKPV proves to be a simple and universally applicable indicator for predicting SKF., (© 2023. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Introduction: The radiographic grading of voiding cystourethrogram (VCUG) images is often used to determine the clinical course and appropriate treatment in patients with vesicoureteral reflux (VUR). However, image-based evaluation of VUR remains highly subjective, so we developed a supervised machine learning model to automatically and objectively grade VCUG data., Study Design: A total of 113 VCUG images were gathered from public sources to compile the dataset for this study. For each image, VUR severity was graded by four pediatric radiologists and three pediatric urologists (low severity scored 1-3; high severity 4-5). Ground truth for each image was assigned based on the grade diagnosed by a majority of the expert assessors. Nine features were extracted from each VCUG image, then six machine learning models were trained, validated, and tested using 'leave-one-out' cross-validation. All features were compared and contrasted, with the highest-ranked then being used to train the final models., Results: F1-score is a metric that is often used to indicate performance accuracy of machine learning models. When using the highest-ranked VCUG image features, F1-scores for the support vector machine (SVM) and multi-layer perceptron (MLP) classifiers were 90.27 % and 91.14 %, respectively, indicating a high level of accuracy. When using all features combined, F1 scores were 89.37 % for SVM and 90.27 % for MLP., Discussion: These findings indicate that a distorted pattern of renal calyces is an accurate predictor of high-grade VUR. Machine learning protocols can be enhanced in future to improve objective grading of VUR., Competing Interests: Conflict of interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Purpose: To investigate the value of CT urography (CTU) indicators in the quantitative differential diagnosis of bladder urothelial carcinoma (BUC) and inverted papilloma of the bladder (IPB)., Material and Methods: The clinical and preoperative CTU imaging data of continuous 103 patients with histologically confirmed BUC or IPB were retrospectively analyzed. The imaging data included 6 qualitative indicators and 7 quantitative measures. The recorded clinical information and imaging features were subjected to univariate and multivariate logistic regression analysis to find independent risk factors for BUC, and a combined multi-indicator prediction model was constructed, and the prediction model was visualized using nomogram. ROC curve analysis was used to calculate and compare the predictive efficacy of independent risk factors and nomogram., Results: Junction smoothness, maximum longitudinal diameter, tumor-wall interface and arterial reinforcement rate were independent risk factors for distinguishing BUC from IPB. The AUC of the combined model was 0.934 (sensitivity = 0.808, specificity = 0.920, accuracy = 0.835), and its diagnostic efficiency was higher than that of junction smoothness (AUC=0.667, sensitivity = 0.654, specificity = 0.680, accuracy = 0.660), maximum longitudinal diameter (AUC=0.757, sensitivity = 0.833, specificity = 0.604, accuracy = 0.786), tumor-wall interface (AUC=0.888, sensitivity = 0.755, specificity = 0.808, accuracy = 0.816) and Arterial reinforcement rate (AUC=0.786, sensitivity = 0.936, specificity = 0.640, accuracy = 0.864)., Conclusion: Above qualitative and quantitative indicators based on CTU and the combination of them may be helpful to the differential diagnosis of BUC and IPB, thus better assisting in clinical decision-making., Key Points: 1. Bladder urothelial carcinoma (BUC) and inverted papilloma of the bladder (IPB) exhibit similar clinical symptoms and imaging presentations. 2. The diagnostic value of CT urography (CTU) in distinguishing between BUC and IPB has not been documented. 3. BUC and IPB differ in lesion size, growth pattern and blood supply. 4. The diagnostic efficiency is optimized by integrating multiple independent risk factors into the prediction model., (© 2024. The Author(s).)

Background: Urinary system anomalies, both congenital and acquired, constitute a relatively common clinical problem in children. The main role of diagnostic imaging is to determine early diagnosis and support therapeutic decisions to prevent the development of chronic renal disease. The aim of this study was to evaluate the utility of magnetic resonance urography (MRU) in assessment of urinary system in children, by comparing differential renal function calculated using MRU with dynamic renal scintigraphy (DRS)., Materials and Methods: The study group consisted of 46 patients aged 1 week to 17 years (median 7 (0.5; 13) years, 17 (37%) girls, 29 (63%) boys), who underwent dynamic renal scintigraphy due to various clinical reasons. All participants underwent MRU, which was used to measure differential renal function. Functional analysis was performed using dedicated external software (CHOP-fMRU and pMRI without prior knowledge of DRS results. MRU results acquired using pMRI were assessed for inter and intraobserver agreement., Results: Statistical analysis of the results showed excellent agreement between MRU and DRS in measuring differential renal function with Pearson correlation coefficient 0.987 for CHOP-fMRU and 0.971 for pMRI, p < 0.001. Interclass correlation coefficient (ICC) for these programs was 0.987 (95% CI 0.976-0.993) and 0.969 (95% CI 0.945-0.983) respectively, p < 0.001. The Bland-Altman 95% limits of agreement for CHOP-fMRU results vs. DRS was - 6.29-5.50 p.p. and for pMRI results vs. DRS - 9.15-9.63 p.p. The differential renal function measurements calculated in pMRI showed excellent intraobserver and interobserver agreement with ICC 0.996 (95% CI 0.994-0.998) and 0.992 (95% CI 0.986-0.996) respectively, p < 0.001., Conclusions: The study showed no significant differences between magnetic resonance urography and dynamic renal scintigraphy in calculating differential renal function. It indicates high utility of MRU in the evaluation of urinary system in children., (© 2024. The Author(s).)

Purpose: To explore the feasibility of measuring glomerular filtration rate (GFR) using iodine maps in dual-energy spectral computed tomography urography (DEsCTU) and correlate them with the estimated GFR (eGFR) based on the equation of creatinine-cystatin C., Materials and Methods: One hundred and twenty-eight patients referred for DEsCTU were retrospectively enrolled. The DEsCTU protocol included non-contrast, nephrographic, and excretory phase imaging. The CT-derived GFR was calculated using the above 3-phase iodine maps (CT-GFR iodine ) and 120 kVp-like images (CT-GFR 120kvp ) separately. CT-GFR iodine and CT-GFR 120kvp were compared with eGFR using paired t-test, correlation analysis, and Bland-Altman plots. The receiver operating characteristic curves were used to test the renal function diagnostic performance with CT-GFR 120kvp and CT-GFR iodine ., Results: The difference between eGFR (89.91 ± 18.45 ml·min -1 ·1.73 m -2 ) as reference standard and CT-GFR iodine (90.06 ± 20.89 ml·min -1 ·1.73 m -2 ) was not statistically significant, showing excellent correlation (r = 0.88, P < 0.001) and agreement (± 19.75 ml·min -1 ·1.73 m -2 , P = 0.866). The correlation between eGFR and CT-GFR 120kvp (66.13 ± 19.18 ml·min -1 ·1.73 m -2 ) was poor (r = 0.36, P < 0.001), and the agreement was poor (± 40.65 ml·min -1 ·1.73 m -2 , P < 0.001). There were 62 patients with normal renal function and 66 patients with decreased renal function based on eGFR. The CT-GFR iodine had the largest area under the curve (AUC) for distinguishing between normal and decreased renal function (AUC = 0.951)., Conclusion: The GFR can be calculated accurately using iodine maps in DEsCTU. DEsCTU could be a non-invasive and reliable one-stop-shop imaging technique for evaluating both the urinary tract morphology and renal function., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objectives: To compare the image quality and diagnostic performance of low-dose CT urography to that of concurrently acquired conventional CT using dual-source CT., Methods: This retrospective study included 357 consecutive CT urograms performed by third-generation dual-source CT in a single institution between April 2020 and August 2021. Two-phase CT images (unenhanced phase, excretory phase with split bolus) were obtained with two different tube current-time products (280 mAs for the conventional-dose protocol and 70 mAs for the low-dose protocol) and the same tube voltage (90 kVp) for the two X-ray tubes. Iterative reconstruction was applied for both protocols. Two radiologists independently performed quantitative and qualitative image quality analysis and made diagnoses. The correlation between the noise level or the effective radiation dose and the patients' body weight was evaluated., Results: Significantly higher noise levels resulting in a significantly lower liver signal-to-noise ratio and contrast-to-noise ratio were noted in low-dose images compared to conventional images (P < .001). Qualitative analysis by both radiologists showed significantly lower image quality in low-dose CT than in conventional CT images (P < .001). Patient's body weight was positively correlated with noise and effective radiation dose (P < .001). Diagnostic performance for various diseases, including urolithiasis, inflammation, and mass, was not different between the two protocols., Conclusions: Despite inferior image quality, low-dose CT urography with 70 mAs and 90 kVp and iterative reconstruction demonstrated diagnostic performance equivalent to that of conventional CT for identifying various diseases of the urinary tract., Advances in Knowledge: Low-dose CT (25% radiation dose) with low tube current demonstrated diagnostic performance comparable to that of conventional CT for a variety of urinary tract diseases., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Institute of Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: Computed tomography urography (CTU) comprehensively evaluates the urinary tract. However, the procedure is associated with a high radiation dose due to multiple scan series and therefore requires optimisation. The study performed CTU protocol optimisation based on a reduction in tube voltage (kV) using quality assurance (QA) phantom and clinical images and evaluated image quality and radiation dose., Methods: The study was prospectively conducted on patients referred for CTU. The patients were grouped into A and B and were scanned with the standard protocol, a protocol used for the routine CTU at the CT centre before optimisation, and optimised protocol, a protocol with reduced kV respectively. The protocols were first tried on a quality assurance (QA) phantom before being applied to patients, and image quality was assessed based on signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). In addition, the clinical images were assessed based on the visibility of the anatomical criteria for CT images by five observers with >5 years of experience. The data were analysed using both visual grading characteristic (VGC) curves and statistical package for social sciences (SPSS) version 22.0., Results: The dose was significantly lower in the optimised protocol with a 10 % reduction in both volume computed tomography dose index and (CTDIvol) and dose length product (DLP) for the phantom images, and a 26 % reduction in CTDIvol and 28 % in DLP for the clinical images. However, there was no significant difference in image quality noted between the standard and optimised protocols based on the quantitative and qualitative image quality evaluation using both the QA phantom and clinical images., Conclusion: The findings revealed a significant dose reduction in the optimised protocol. Further, image quality in standard and optimised protocols did not differ significantly based on quantitative and qualitative methods., Implication for Practice: kV optimisation in contrast-enhanced procedures provides dose reduction and should be encouraged in the medical imaging departments., Competing Interests: Conflict of interest statement None., (Copyright © 2023 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.)

Purpose: To assess discrepancies in current imaging recommendations for hematuria among North American societies: American College of Radiology (ACR), American Urological Association (AUA), and Canadian Urological Association (CUA)., Methods: The latest available ACR Appropriateness Recommendations, AUA guidelines, and CUA guidelines were reviewed. AUA and CUA guidelines imaging recommendations by variants and level of appropriateness were converted to match the style of ACR. Imaging recommendations including modality, anatomy, and requirement for contrast were recorded., Results: Clinical variants included microhematuria without risk factors, microhematuria with risk factors, gross hematuria, and microhematuria during pregnancy. CUA recommends ultrasound kidneys as the first-line imaging study in the first 3 variants; pregnancy is not explicitly addressed. For hematuria without risk factors, ACR does not routinely recommend imaging, while AUA recommends shared decision-making to decide repeat urinalysis versus cystoscopy with ultrasound kidneys. For hematuria with risk factors and gross hematuria, ACR recommends CT urography; MR urography can also be considered in gross hematuria. AUA further stratifies intermediate- and high-risk patients, for which ultrasound kidneys and CT urography are recommended, respectively. For pregnancy, ACR and AUA both recommend ultrasound kidneys, though AUA additionally recommends consideration of CT or MR urography after delivery., Conclusion: There is no universally agreed upon algorithm for diagnostic evaluation. Discrepancies centered on the role of upper tract imaging with ultrasound versus CT. Prospective studies and/or repeat simulation studies that apply newly updated guidelines are needed to further clarify the role of imaging, particularly for patients with microhematuria with no and intermediate risk factors., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objectives: Development and validation of a computed tomography urography (CTU)-based machine learning (ML) model for prediction of preoperative pathology grade of upper urinary tract urothelial carcinoma (UTUC)., Methods: A total of 140 patients with UTUC who underwent CTU examination from January 2017 to August 2023 were retrospectively enrolled. Tumor lesions on the unenhanced, medullary, and excretory periods of CTU were used to extract Features, respectively. Feature selection was screened by the Pearson and Spearman correlation analysis, least absolute shrinkage and selection operator algorithm, random forest (RF), support vector machine (SVM), and eXtreme Gradient Boosting (XGBoost). The logistic regression (LR) was used to screen for independent influencing factors of clinical baseline characteristics. Machine learning models based on different feature datasets were constructed and validated using algorithms such as LR, RF, SVM, and XGBoost. By computing the selected features, a radiomics score was generated, and a diverse feature dataset was constructed. Based on the training set, 16 ML models were created, and their performance was evaluated using the validation set for metrics including sensitivity, specificity, accuracy, area under the receiver operating characteristic curve (AUC), and others., Results: The training set consisted of 98 patients (mean age: 64.5 ± 10.5 years; 30 males), whereas the validation set consisted of 42 patients (mean age: 65.3 ± 9.78 years; 17 males). Hydronephrosis was the best independent influence factor (p < 0.05). The RF model had the best performance in predicting high-grade UTUC, with AUC of 0.914 (95% Confidence Interval [95%CI] 0.852-0.977) and 0.903 (95%CI 0.809-0.997) in the training set and validation set, and accuracy of 0.878 and 0.857, respectively., Conclusions: An ML model based on the RF algorithm exhibits excellent predictive performance, offering a non-invasive approach for predicting preoperative high-grade UTUC., (© 2024 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Objective: To determine the accuracy of material-specific images derived from contrast-enhanced dual-energy CT urography (DECTU) in detecting and measuring urinary stones in comparison with that of unenhanced images and its utility in calcified stone differentiation., Methods: 105 patients with 202 urinary stones (121 had confirmed composition by infrared spectroscopy) underwent triphasic (unenhanced, portal venous (VP) and excretory phase (EP)) DECTU. Material-specific images were derived in VP and EP with calcium-water, calcium-iodine and CaOxalate&#95;Dihydrate (COD)-Hydroxyapatite (HAP) as basis material pairs. Stone number and size were recorded on unenhanced images and VP and EP material-specific images, where stone densities were also measured. Material densities of calcified stones (pure calcium oxalate [pCaO, n = 34], mixed calcium oxalate [mCaO, n = 14], mixed carbonate phosphate [mCaP, n = 70]) were compared and thresholds for differentiating these stones were determined using receiver operating characteristic analysis., Results: All 202 urinary stones were detected on the unenhanced, calcium (water) and calcium (iodine) images in VP. While the detection rate was significantly decreased to 58 and 64% using calcium (water) and calcium (iodine) images in EP, respectively (all p < 0.001). Stone sizes measured on calcium (iodine) images in VP was similar to that of unenhanced images (10.6 vs  10.7 mm, p > 0.05). Significant differences in material densities were found among pCaO, mCaO and mCaP on COD(HAP) images with AUC of 0.72-0.74 for differentiating these stones., Conclusion: Material-specific images in VP derived from DECTU allow reliably detecting and measuring urinary tract stones in comparison with unenhanced images and can identify calcified stones with moderate diagnostic performance to provide potential 33% dose reduction., Advances in Knowledge: Material-specific images, especially the calcium (iodine) images in VP allow for reliable detection of urinary stones.Stone size measurement should be performed on the calcium (iodine) images in VP.Material density measurements on COD-HAP (VP) material decomposition images can be used to differentiate among pure calcium oxalate, mixed calcium oxalate and mixed carbonate phosphate stones with AUC of 0.72-0.74.

Background:  Functional MR urography (fMRU) has developed into an innovative, radiation-free option for assessing parameters of kidney function in pediatric radiology. The importance of fMRU in comparison to the standardized established nuclear medicine procedure (99mTc-Mercapto-acetyltriglycerine, MAG3 scintigraphy) is shown using SWOT analysis., Methods:  To assess the current state of research, a selective literature search was carried out in PubMed. Taking into account the current scientific status, the examination technique, preparation, and evaluation of fMRU are presented., Results:  As a result of the comparison with MAG3, fMRU is suitable for certain indications and represents an optimal combination of morphological and functional representation of the kidneys and urinary tract, especially in the case of surgical consequences., Conclusion:  fMRU has been successfully established as a diagnostic method for assessing the morphology and function of the kidneys in competition with MAG3 scintigraphy., Key Points:   · Functional MRU allows reliable statements on the morphology and function of the kidneys and urinary tract.. · The results of the functional assessment of fMRU are comparable to the results of MAG3 scintigraphy.. · The complex implementation and demanding evaluation limits the spread of fMRU as a complete alternative to MAG3 scintigraphy. fMRU is reserved for special indications.. · Functional MRU has prevailed over MAG3 scintigraphy for complex renal and urinary tract anomalies (CAKUT) that require surgical correction. An example is the clarification of dribbling in girls, which is usually based on an ectopic opening of a ureter in a double system.., Citation Format: · Kirsch H, Krüger P, John-Kroegel U et al. Functional MR urography in children - update 2023. Fortschr Röntgenstr 2023; 195: 1097 - 1105., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Background: A well-established definition of obstruction in the setting of congenital hydronephrosis is lacking. Multiple imaging modalities and radiographic characteristics or parameters have been described to help confirm the diagnosis of ureteropelvic junction obstruction (UPJO). We sought to evaluate the change in anterior-posterior renal pelvic diameter (APRPD) following furosemide administration in patients with unilateral hydronephrosis and confirmed UPJO on functional magnetic resonance urography (fMRU) who underwent pyeloplasty., Materials and Methods: There were 49 patients who met inclusion criteria (11 females, 38 males; average age 2.2 years, SD 3.4 years) from February 2006 to September 2020, diagnosed with unilateral hydronephrosis (SFU Grade 3-4) who underwent fMRU prior to pyeloplasty for confirmed UPJO. 29 of the included patients also underwent a post-pyeloplasty fMRU. A weight-adjusted dose of 1 mg/kg of furosemide (max 20 mg/kg) was administered intravenously. Two board-certified pediatric radiologists measured the APRPD of the obstructed and non-dilated kidneys prior to pyeloplasty and APRPD of the hydronephrotic kidneys on the post-pyeloplasty follow up fMRUs. Measurements were performed on images prior to and approximately 30 min following furosemide injection., Results: The average APRPD before furosemide injection in the obstructed kidney prior to pyeloplasty was 26.3 mm (SD 9.0 mm) compared to the non-dilated (not obstructed) kidney measurement of 5.1 mm (SD 3.6 mm) (p < 0.001). Following administration of furosemide, the average APRPD was 31.4 mm (SD 8.8 mm) in the obstructed kidney, and 7.8 mm (SD 4.1 mm) in the non-dilated kidney (p < 0.001). After pyeloplasty, the pre-furosemide APRPD measurement was 17.8 mm (SD 11 mm), which was significantly less compared to the pre-pyeloplasty APRPD (p < 0.001). The post-pyeloplasty, post-furosemide APRPD measurement was 25.8 mm (SD 12 mm), also significantly less compared to the pre-pyeloplasty measurement (p = 0.02). The changes in APRPD in the obstructed kidney prior to pyeloplasty was 5.1 mm (SD 3.5 mm) and after pyeloplasty was 8 mm (SD 4.6 mm) (p = 0.002). Change in APRPD in the non-dilated kidney was 2.7 mm (SD 2.3 mm). Percent APRPD change in the obstructed kidney was 22.9% (SD 18.5%), which was significantly less than 33.3% (SD 22.1%) in the post-pyeloplasty kidney (p = 0.028) and 82.8% (SD 87.9%) in the non-dilated kidney (p < 0.001)., Conclusions: A relatively smaller change in APRPD on fMRU following administration of furosemide in the setting of UPJO may serve as another predictive characteristic of obstructed kidneys., Competing Interests: Conflict of interest Dr. Kirsch is a consultant for Palette Life Sciences, a speaker for Intuitive Surgical, and is the Co-founder and CEO of Global Continence, Inc. Dr. Linam, Dr. Janssen, Dr. Cho, and Ms. Stone have no disclosures., (Copyright © 2023 Journal of Pediatric Urology Company. All rights reserved.)

Background: To determine the utility of contrast-enhanced voiding urography (CeVUS) in the treatment of vesicoureteral reflux (VUR) through ureterovesical reimplantation in children., Methods: A total of 159 children with recurrent urinary tract infections were selected for CeVUS and voiding cystourethrography (VCUG) from December 2018 to December 2020, among whom 78 patients were eventually diagnosed with VUR. Overall, 60 pyelo-ureteric units (PUUs) were operated according to surgical indications. Accordingly, we determined the general clinical characteristics of all children, obtained two-dimensional ultrasound images, assessed the reflux status of children using the contrast-enhanced technique, and compared the obtained results via CeVUS and VCUG. Both imaging modalities were reperformed at 6, 12, and 18 months after surgery to evaluate postoperative outcomes. In particular, we assessed the consistency of the evaluation and calculated the diagnostic efficacy of CeVUS for different levels of reflux at different time points., Results: CeVUS showed considerable efficacy in the diagnosis of children with VUR. Notably, the diagnostic results of both CeVUS and VCUG achieved high agreement, with a kappa value of 0.966 (P < 0.001). The results of our follow-up at different stages and evaluation of postoperative efficacy revealed that CeVUS possessed substantial diagnostic efficacy and good consistency with VCUG., Conclusion: CeVUS is an accurate and safe examination, with considerable clinical significance for diagnosing VUR in children, determining the treatment approach, conducting follow-up during treatment, and evaluating subsequent treatment outcomes., (© 2023. The Author(s).)

Introduction: Citing high costs, limited diagnostic benefit, and ionizing radiation-associated risk from CT urogram, in 2020 the AUA revised its guidelines from recommending CT urogram for all patients with microscopic hematuria to a deintensified risk-stratified approach, including the deimplementation of low-value CT urogram (ie, not recommending CT urogram for patients with low- to intermediate-risk microscopic hematuria). Adherence to revised guidelines and reasons for continued low-value CT urogram are unknown., Methods: With the overarching objective of improving guideline implementation, we used a mixed-method convergent explanatory design with electronic health record data for a retrospective cohort at a single academic tertiary medical center in the southeastern United States and semistructured interviews with urology and nonurology providers to describe determinants of low-value CT urogram following guideline revision., Results: Of 391 patients with microscopic hematuria, 198 (51%) had a low-value CT urogram (136 [69%] pre-guideline revision, 62 [31%] postrevision). The odds of ordering a low-value CT urogram were lower after guideline revisions, but the change was not statistically significant (OR: 0.44, P = .08); odds were 1.89 higher ( P = .06) among nonurology providers than urology providers, but the difference was not statistically significant. Provider interviews suggested low-value CT urogram related to nonurology providers' limited awareness of revised guidelines, the role of clinical judgment in microscopic hematuria evaluation, and professional and patient influences., Conclusions: Our findings suggest low-value CT urogram deimplementation may be improved with guidelines and implementation support directed at both urology and nonurology providers and algorithms to support guideline-concordant microscopic hematuria evaluation approaches. Future studies should test these strategies.

Purpose: Microhematuria is a highly prevalent condition with a low associated risk of urothelial and upper tract malignancy. The AUA Guidelines recently changed recommendations for imaging favoring renal ultrasound for low- and intermediate-risk patients with microhematuria. We summarize the diagnostic test characteristics of computed tomography urography, renal ultrasound, and magnetic resonance urography in comparison with surgical pathology for the diagnosis of upper urinary tract cancer in microhematuria and gross hematuria patients., Materials and Methods: This study is a systematic review and meta-analysis using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines from evidence collected for the 2020 AUA Microhematuria Guidelines report, including studies assessing imaging following diagnosis of hematuria published from January 2010 through December 2019., Results: The search identified 20 studies which reported the prevalence of malignant and benign diagnoses in relation to imaging modality, of which 6 were included in the quantitative analysis. For the detection of renal cell carcinoma and upper urinary tract carcinoma in patients with microhematuria and gross hematuria, computed tomography urography had a sensitivity of 94% (95% CI, 84%-98%) and a specificity of 99% (95%CI, 97%-100%) with a certainty of evidence rating of very low and low, respectively when 4 studies were pooled. In comparison, ultrasound demonstrated a sensitivity ranging from 14%-96% (low certainty of evidence) and a specificity of 99%-100% in 2 studies (moderate certainty of evidence), while magnetic resonance urography demonstrated a sensitivity of 83% and specificity of 86% in 1 study with a low certainty of evidence., Conclusions: In a limited data set for each individual imaging modality, computed tomography urography appears the most sensitive imaging modality for the diagnostic evaluation of microhematuria. Future studies will be needed to evaluate the clinical and health system financial impacts of the change in guideline recommendations from computed tomography urography to renal ultrasound in evaluating low- and intermediate-risk patients with microhematuria.

Magnetic resonance urography (MRU) is an important MRI application that provides noninvasive comprehensive morphological and functional evaluation of the kidneys and urinary tract. It can be used to assess congenital anomalies of the kidney and urinary tract, which often present as urinary tract dilation. In children, MRU allows for high tissue contrast and high spatial resolution without requiring ionizing radiation. Magnetic resonance urography requires patient preparation in the form of pre-examination intravenous hydration, placement of a urinary catheter, and the administration of diuretics at the time of the exam. The imaging protocol is based on T2-weighted images for anatomical assessment and dynamic post-contrast images for functional evaluation. These images are then used to generate quantitative and graphic results including contrast transit and excretion time as well as to calculate differential renal function. This review focuses on a simple approach to pediatric MRU acquisition and interpretation based on clinical cases and the authors' experience., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

CT urography is a single term used to refer to different scanning protocols that can be applied for a number of clinical indications. If, on the one hand, this highlights the role of the radiologist in deciding the most suitable technique to perform according to the patient's needs, on the other hand, a certain confusion may arise due to the different technical and clinical variables that have to be taken into account. This has been well demonstrated by a previous work based on an online questionnaire administered to a population of Italian radiologists that brought out similarities as well as differences across the national country. Defining precise guidelines for each clinical scenario, although desirable, is a difficult task to accomplish, if not even unfeasible. According to the prementioned survey, five relevant topics concerning CT urography have been identified: definition and clinical indications, opacification of the excretory system, techniques, post-processing reconstructions, and radiation dose and utility of dual-energy CT. The aim of this work is to deepen and share knowledge about these main points in order to assist the radiology in the daily practice. Moreover, a synopsis of recommendations agreed by the Italian board of genitourinary imaging is provided., (© 2023. Italian Society of Medical Radiology.)

Computed tomography (CT) of the abdomen is usually appropriate for the initial imaging of many urinary tract diseases, due to its wide availability, fast scanning and acquisition of thin slices and isotropic data, that allow the creation of multiplanar reformatted and three-dimensional reconstructed images of excellent anatomic details. Non-enhanced CT remains the standard imaging modality for assessing renal colic. The technique allows the detection of nearly all types of urinary calculi and the estimation of stone burden. CT is the primary diagnostic tool for the characterization of an indeterminate renal mass, including both cystic and solid tumors. It is also the modality of choice for staging a primary renal tumor. Urolithiasis and urinary tract malignancies represent the main urogenic causes of hematuria. CT urography (CTU) improves the visualization of both the upper and lower urinary tract and is recommended for the investigation of gross hematuria and microscopic hematuria, in patients with predisposing factors for urologic malignancies. CTU is highly accurate in the detection and staging of upper tract urothelial malignancies. CT represents the most commonly used technique for the detection and staging of bladder carcinoma and the diagnostic efficacy of CT staging improves with more advanced disease. Nevertheless, it has limited accuracy in differentiating non-muscle invasive bladder carcinoma from muscle-invasive bladder carcinoma. In this review, clinical indications and the optimal imaging technique for CT of the urinary tract is reviewed. The CT features of common urologic diseases, including ureterolithiasis, renal tumors and urothelial carcinomas are discussed., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Dual-energy computed tomography scans can provide significant benefits to the urinary system. The aim of this study is to determine the limitations and benefits of using dual energy CT urography in patients with urinary system stones and cysts., Methods: In the analysis of the images, the virtual noncontrasted images obtained from the combined nephrogenicexcretory phase and the true noncontrasted images were evaluated. The true noncontrast images were accepted as the gold standard for stone detection., Results: Eighty-three different stones were detected in 26 of the 115 patients included in the study. Sensibilities of virtual noncontrast images in detecting urinary system stones were 66.7% and 65.4% according to the first and second radiologists, respectively. In this study, 32 hyperdense cysts were detected. According to iodine map images, there was no enhancement in 26 of 32 cysts; only 5 cysts showed minimal contrast enhancement. One patient could not decide on contrast enhancement., Discussion: As a result, if CT urography is performed with dual energy, it can provide additional information in patients with urinary system disorder.

Purpose: To evaluate the feasibility and usefulness of cine magnetic resonance urography (cine MRU) as a novel postoperative examination after upper urinary tract reconstruction surgery., Methods: Ninety-six patients underwent cine MRU for postoperative evaluation between August 2015 and August 2020. The morphological observations included regular peristalsis, anastomosis, urine flow signals, and reflux. The quantitative evaluations included luminal diameter, peristaltic amplitude, contraction ratio, peristaltic waves, and ureteric jets. The surgical outcomes were classified as success, gray area, or failure by combining the results of cine MRU, symptoms, and the degree of hydronephrosis., Results: There was no obvious stenosis of the anastomosis in 83 patients (86.46%). Regular peristalsis of the ureter and signals of urination was observed in 85 (88.54%) and 84 patients (87.50%), respectively. In addition, three patients (3.13%) showed urine reflux. The patients in both the success group and the gray area group showed significantly different creatinine levels (success 86.2 ± 22.3 μmol/L vs. failure 110.7 ± 8.2 μmol/L, P = 0.016; gray area 81.0 ± 20.0 μmol/L vs. failure 110.7 ± 8.2 μmol/L, P = 0.009) and estimated glomerular filtration rate (success: 88.5 ± 23.1 mL/min·1.73 m 2 , failure: 61.6 ± 14.1 mL/min·1.73 m 2 , P = 0.014; gray area: 94.7 ± 24.6 mL/min·1.73 m 2 , failure: 61.6 ± 14.1 mL/min·1.73 m 2 , P = 0.007) compared to those in the failure group. The ipsilateral split renal function was 33.6 ± 15.0, 24.5 ± 13.4, and 20.1 ± 0.4 mL/min in the success, gray area, and failure groups, respectively ( P = 0.354)., Conclusion: Cine MRU demonstrates the morphology and function of the reconstructed upper urinary tract. The results of cine MRU can be used to evaluate the surgical effect, providing guidance for further treatment.

Hematuria is defined usually as the presence of blood in the urine, either on voiding or in a catheterized specimen. Hematuria is broadly divided into microscopic and gross hematuria and may be symptomatic or asymptomatic. The causes of hematuria include a very wide spectrum of conditions. However, here, we have filtered the causes causing gross hematuria, including calculus, trauma, tumors, vascular, and miscellaneous causes. Plain X-rays of the kidney, ureter, and bladder; ultrasound; intravenous urography; computed tomography (CT); magnetic resonance imaging; retrograde ureterography and pyelography (RGP); cystoscopy; and ureteroscopy are techniques that are useful for diagnosis. In the past, one or a combination of several techniques was used to evaluate hematuria but recently, advances in CT urography mean that it can be used alone for this task. This article briefly reviews the common causes of gross hematuria in adults and their evaluation by CT-based urography. Gross hematuria is evaluated well with CT scan urography which includes an unenhanced scan, the nephrographic phase, and the excretory phase. Unenhanced scans are routinely performed to evaluate the basic parameters such as the size, shape, position, and outline of the kidneys and calculus disease, which is the most common cause of hematuria. Renal parenchymal diseases including masses are best visualized in the nephrographic phase along with other abdominal organs. Delayed excretory phases including the kidneys, ureters, and bladder are useful for detecting urothelial diseases. CT urography's protocol permits evaluations of hematuria through a single examination., (Copyright © 2023 Copyright: © 2023 Saudi Journal of Kidney Diseases and Transplantation.)

Objective: To determine the sensitivity of dual-energy (DE) virtual non-contrast computed tomography (vNCT), generated from the excretory phase of a CT urogram, compared to true non-contrast CT (tNCT) for the detection of urinary calculi., Methods: A search of multiple medical literature databases was performed using predetermined search terms. Inclusion and exclusion criteria were applied, and bias risk was assessed by two independent reviewers using the quality assessment of diagnostic accuracy studies (QUADAS) tool. Collated estimates of sensitivity were generated, and sources of heterogeneity were identified and reviewed., Results: Thirteen studies (1760 patients; 1740 urinary calculi) were included for sensitivity assessment. Pooled sensitivity for urinary calculi on vNCT was 78.1% (95% CI: 70.2 to 85.0%); however, heterogeneity between studies was very high (I 2 = 92.0%). Sources of heterogeneity between studies were explored through subgroup analysis by categorising studies according to slice thickness (≥ 2 mm and < 2 mm), use of oral hydration, and use of intravenous furosemide. Pooled sensitivity for detection of urinary calculi on vNCT for studies that used oral hydration and < 2 mm slice thickness was 92.2% (95% CI: 89.5 to 94.5%). Pooled specificity was not performed as true negatives were not reported in most studies. Potential sources of bias were identified in included studies., Conclusion: vNCT demonstrated a moderate pooled sensitivity compared to tNCT for the detection of urinary calculi in split bolus CT urogram protocols. However, subgroup analysis suggests higher sensitivity when employing oral hydration and < 2 mm slice thickness or increment., Key Points: • vNCT demonstrated moderate pooled sensitivity for the detection of urinary calculi in split bolus CT urogram protocols. • Subgroup analysis suggested higher sensitivity with oral hydration and < 2 mm slice thickness or increment., (© 2022. Crown.)

Abdominal colic pain or hematuria is suspected to be caused by urinary tract stones. Commonly used X-ray examinations include kidney-ureter-bladder plain radiography (KUB), intravenous urography (IVU), and abdominal computed tomography (CT). In this study, a high-sensitivity thermoluminescent dosimeter (TLD) was embedded in a Rando phantom to directly measure organ dose and evaluate effective dose. During each experiment, 139 TLD measurement points that cover almost all organs (as recommended by the ICRP 103 report) were examined. Red bone-marrow and remainder tissues have a high tissue weighting factor (0.12), and they are widely distributed. In the phantom, 34 TLDs and 31 TLDs were embedded in the red bone-marrow and remainder tissues to improve the accuracy and representativeness of organ doses. The detailed organ dose distributions for KUB, IVU, and abdominal CT are presented. The effective doses for KUB and IVU were 0.22 and 1.51 mSv, respectively, and those for two abdominal CTs were 8.21 and 9.27 mSv. This experiment presents a conversion factor of 0.0177 mSv·mGy -1  cm -1 for the abdominal CT examination, which differs from most of the conversion factors obtained through the Monte Carlo simulation method., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objective: To evaluate the detection and quantification of urinary stones using virtual unenhanced images (VUE) at different phases and slice thickness in contrast-enhanced dual-energy CT Urography (DECTU) in comparison with true unenhanced images (TUE)., Methods: One hundred and twelve urinary stone patients who required triphasic DECTU were analyzed. Data were reconstructed as the followings: TUE images with 1.25 mm thickness (TUE portal venous phase VUE images with 1.25 and 5-mm thickness (VUE(VP)&#95;1.25 mm and VUE(VP)&#95;5 mm) and excretory phase VUE images with 1.25 and 5-mm thickness (VUE(EP)&#95;1.25mm and VUE(EP)&#95;5mm). The. The stones were divided into large (≥5 mm) and small stones. The detection rate, size and CT value of stones were assessed by 2 radiologists and statistically compared among the above groups., Results: Two hundred and thirty urinary stones (163 large and 67 small stones) were detected on TUE&#95;1.25 mm images. For large stones, the detection rate on VUE(VP)&#95;1.25 mm, VUE(VP)&#95;5 mm, VUE(EP)&#95;1.25 mm and VUE(EP)&#95;5 mm was 100%, 96.9%, 85.9%, and 80.4%; while for small stones, the rate was 77.6%, 37.3%, 46.3%, and 23.9%, respectively. VUE(VP) images significantly improved the stone detection rate compared with VUE(EP) images at both slice thicknesses. In general, VUE images identified stones with smaller sizes and lower Hounsfield units, but thinner slice thickness images reduced the inaccuracy. Inter-reader agreement of the stone detection revealed a k value range from 0.85 to 0.94 for TUE and VUE images., Conclusion: Large stones (≥5 mm) can reliably be detected on thin section VUE(VP) images with 33% radiation dose reduction. However, for small stones TUE remains superior. Stone size is underestimated on VUE images., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: To assess the inter-observer and intra-observer reliability of the magnetic resonance urography (MRU)-upper urinary tract dilation (UUTD) grading system., Methods: A total of 40 patients with a diagnosis of NB were enrolled in this study. The images were assembled in an electronic presentation randomly. The presentations were reviewed and graded by 4 junior and 4 senior urologists. One week later, the images were randomized again and reassessed. The inter-observer reliability was estimated by Kendall's coefficient of concordance and intra-class correlation coefficient (ICC), and the intra-observer reliability was estimated by weighted Cohen's kappa., Results: The inter-observer reliability strength was excellent for all urologists, with the ICC value of 0.939 (0.908-0.963) and Kendall's W value of 0.967. The highest agreement was shown in Grade 4 at 92.50%, and the lowest in Grade 2 at 82.14%. All disagreements were within one grade of difference. Moreover, the Intra-observer reliability was excellent, with the weighted kappa value ranging from 0.904 to 0.954., Conclusions: The inter-observer and intra-observer reliability of this novel MRU-UUTD grading system is confirmed, providing adequate evidence for broader clinical application., (© 2022. The Author(s).)

Methods: We grouped the patients who had undergone cervical cancer surgery in a hospital in this article and compared the nanodrug carrier system under CT imaging with traditional laparoscopy. The postoperative physical parameters of surgical patients are collected from cervical cancer patients of different degrees, and the parameters and prognostic health of patients after different operations are compared., Results: The results of the study show that the postoperative patient's body parameters of the nanodrug delivery system under the CT imaging technology used in this article are better than those of the traditional surgery group, and the average intraoperative blood loss is about 20% less than that of the traditional surgery. Postoperative complications occur. The situation is even lower, more than 30% lower than traditional surgery., Conclusion: This shows that the operation of the nanodrug delivery system based on CT imaging technology has broken through some of the limitations of the development of laparoscopic technology and has played an important role in the surgical treatment of cervical cancer., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2022 Song Lin et al.)

Objective: To compare image quality and radiation dose between single-bolus 2-phase and split-bolus 1-phase CT Urography (CTU) performed immediately after microwave ablation (MWA) of clinically localized T1 (cT1) RCC., Methods: Forty-two consecutive patients (30 M, mean age 67.5 ± 9.0) with cT1 RCC were treated with MWA from 7/2013 to 12/2013 at two academic quaternary-care institutions. Renal parenchymal enhancement, collecting system opacification and distention and size-specific dose estimate (SSDE) were quantified and image quality subjectively assessed on single-bolus 2-phase versus split-bolus 1-phase CTU. Kruskal-Wallis and Pearson's Chi-squared tests were performed to assess differences in continuous and categorical variables, respectively. Two-sample T test with equal variances was used to determine differences in quantitative and qualitative image data., Results: Median tumor diameter was larger [2.9 cm (IQR 1.7-5.3) vs 3.6 cm (IQR 1.7-5.7), p = 0.01] in the split-bolus cohort. Mean abdominal girth (p = 0.20) was similar. Number of antennas used and unenhanced CTs obtained before and during MWA were similar (p = 0.11-0.32). Renal pelvis opacification (2.5 vs 3.5, p < 0.001) and distention (4 mm vs 8 mm, p < 0.001) were improved and renal enhancement (Right: 127 HU vs 177 HU, p = 0.001; Left: 124 HU vs 185 HU, p < 0.001) was higher for the split-bolus CTU. Image quality was superior for split-bolus CTU (3.2 vs 4.0, p = 0.004). Mean SSDE for the split-bolus CTU was significantly lower [163.9 mGy (SD ± 73.9) vs 36.3 mGy (SD ± 7.7), p < 0.001]., Conclusion: Split-bolus CTU immediately after MWA of cT1 RCC offers higher image quality, improved opacification/distention of the collecting system and renal parenchymal enhancement at a lower radiation dose., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Computed tomography-urography is currently the imaging modality of choice for the assessment of the whole urinary tract, giving the possibility to detect and characterize benign and malignant conditions. In particular, computed tomography-urography takes advantage from an improved visualization of the urinary collecting system due to acquisition of delayed scan obtained after excretion of intravenous contrast medium from the kidneys. Nevertheless, the remaining scans are of great help for identification, characterization, and staging of urological tumors. Considering the high number of diseases, urinary segment potentially involved and patients' features, scanning protocols of computed tomography-urography largely vary from one clinical case to another as well as selection and previous preparation of the patient. According to the supramentioned considerations, radiation exposure is also of particular concern. Italian radiologists were asked to express their opinions about computed tomography-urography performance and about its role in their daily practice through an online survey. This paper collects and summarizes the results., (© 2022. Italian Society of Medical Radiology.)

Congenital abnormalities of the kidney and urinary tract include a wide range of malformations ranging from asymptomatic to life-threatening conditions. Although pediatric urogenital system imaging is based on the use of US (pre- and postnatal), voiding cystourethrography and scintigraphic study, magnetic resonance (MR) urography plays a fundamental role in the classification and management of congenital abnormalities of the kidney and urinary tract, giving an overview of the different clinical pictures, thanks to its panoramicity and high anatomical detail. In fact the anomalies of the urinary tract are phenotypically variable because they can affect simultaneously several segments of different embryonic derivation, with complex clinical pictures; they can appear both as isolated phenotypes or as complex malformative conditions, involving renal parenchyma, collecting system and bladder. A deep knowledge of this complex embryogenesis and its possible phenotypic patterns allows a correct interpretation of MR urography images. We describe the embryology and pathophysiology of congenital abnormalities of the kidney and urinary tract as well as MR urography technique and findings. Congenital abnormalities of the kidney and urinary tract are classified into four groups: (1) obstruction (proximal, middle and distal), (2) budding with respect to the Wolffian duct (site and number of ureter), (3) ascent and rotation (ectopia, malrotation and fusion of kidney) and (4) anomaly of metanephric differentiation (dysplasia, megapolicalycosis)., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: To evaluate the diagnostic accuracy of computed tomography-urography (CTU) to rule out urinary bladder cancer (UBC) and whether patients thereby could omit cystoscopy., Methods: All patients evaluated for macroscopic hematuria with CTU with cortico-medullary phase (CMP) and cystoscopy at our institute between 1 st November 2016 and 31 st December 2019 were included. From this study cohort a study group consisting of all UBC patients and a control group of 113 patients randomly selected from all patients in the study cohort without UBC. Two radiologists blinded to all clinical data reviewed the CTUs independently. CTUs were categorized as positive, negative or indeterminate. Diagnostic accuracy and proportion of potential omittable cystoscopies were calculated for the study cohort by generalizing the results from the study group., Results: The study cohort consisted of 2195 patients, 297 of which were in the study group (UBC group, n = 207 and control group, n = 90). Inter-rater reliability was high (κ 0.84). Evaluation of CTUs showed that 174 patients were assesessed as positive (showing UBC), 46 patients as indeterminate (not showing UBC but with limited quality of CTU), and 77 patients as negative (not showing UBC with good quality of CTU). False negative rate was 0.07 (95%, CI 0.04-0.12), false positive rate was 0.01 (95% CI 0.0-0.07) and negative predictive value was 0.99 (95% CI 0.92-1.0). The area under the curve was 0.93 (95% CI 0.90-0.96). Only 2.9% (3/102) with high-risk tumors and 11% (12/105) with low- or intermediate-risk tumors had a false negative CTU. Cystoscopy could potentially have been omitted in 57% (1260/2195) of all evaluations., Conclusions: CTU with CMP can exclude UBC with high accuracy. In case of negative CTU, it might be reasonable to omit cystoscopy, but future confirmative studies with possibly refined technique are needed., (© 2022. The Author(s).)

This article provides a comprehensive review of imaging techniques used to evaluate the equine urinary tract. This overview includes officially recognized modalities and new applications reported in the most current literature. Technical aspects and indications for use of endoscopy and ultrasonography are highlighted. Normal endoscopic and ultrasonographic appearance of the upper and lower urinary tract is described, with characterization of common abnormalities found in patients with hematuria, stranguria, and renal failure. Visual examples of several pathologic conditions from clinical cases are provided. An outline of the main features, potentials, and limitations of radiography, nuclear scintigraphy, and computed tomography is provided., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Excretory urography (EU) had been the most frequently performed imaging modality for uroradiology in the past. With the advances in ultrasonography, and development of cross-sectional urography with CT and MRI, EU is now seldom performed. Consequently, there has been a decline of expertise in this technique. However, EU has multiple advantages such as dynamic nature, easy availability, low cost and radiation burden. These render it potentially very valuable in specific indications like congenital anomalies, urothelial lesions and urinary leaks. This review intends to emphasize the current day relevance of excretory urography, outline the key points of the technique, and describe the pearls and pitfalls of interpretation.

Objective: To explore the application value of the X-ray digital tomographic fusion technique in the diagnosis of urinary system diseases., Methods: 500 patients with suspected urinary diseases in our hospital were examined by three methods: X-ray digital tomographic fusion imaging (DTS), intravenous pyelography (IVP), and abdominal plain film (KUB), and the image quality before and after tomographic fusion was objectively evaluated. The image quality could be divided into three grades: excellent, good, and poor., Results: The image excellent rate of DTS (88%) was higher than that of IVP (27.5%). The sensitivity of DTS in the diagnosis of renal cyst and space occupying of the bladder was higher than that of IVP ( P < 0.05). The accuracy rate of DTS in the diagnosis of urinary calculi was 93.33%, higher than 63.3% of KUB ( P < 0.001). The accuracy rate of DTS in the diagnosis of ureteral stricture was 90%, higher than 65% of IVP ( P =0.03). The accuracy of DTS in the diagnosis of hydronephrosis was higher than that of IVP and KUB ( P < 0.05)., Conclusion: In the examination of urinary system-related diseases, high-definition images can be obtained by timely using sectional fusion technology. Compared with conventional IVP, space occupying lesions such as the bladder and kidney can be displayed more clearly with the help of the tomographic fusion technique, which is helpful to improve the possibility of finding lesions and is of great significance in clinical application., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Chensi Ouyang et al.)

Objective: To assess the possibility of magnetic resonance imaging in diagnosis of complications of kidney and ureteral injury in different periods of traumatic disease., Material and Methods: There were 139 patients with kidney and ureteral injuries between 2015 and 2019. We clarified the MR-signs of renal complications in different periods of traumatic disease., Results: We analyzed the effectiveness of MRI in identification of renal complications compared to ultrasound, excretory urography, computed tomography, intraoperative and follow-up data. High diagnostic accuracy of MRI for early and late manifestations of traumatic disease was demonstrated.

Continent diversion with orthotopic neobladder is the most upcoming form of urinary diversion postradical cystectomy. This allows patients to void through the native urethra preserving the maximal quality of life. These patients with greater life expectancies increasingly present with a wide range of late complications, which also include local recurrences involving neobladder. Such presentations on surveillance scans can be challenging for radiologists unfamiliar with expected post-surgical anatomy and usual sites of local recurrences. Tumour in neobladder, although rare, has predilection concerning specific sites of involvement and few distinct histological types. Major subtypes of such recurrences with corresponding radiological features on multimodality imaging have been discussed in this article. Management of such cases with revision of diversions is challenging, and surgeons expect a meticulous read of such scans before contemplating pelvic clearance and secondary diversions. This pictorial review aims to appraise the literature related to various primary and secondary types of tumours involving reservoir and anastomotic sites in an orthotopic neobladder, their relative incidences and illustrate salient imaging points with case examples.

Purpose: To verify which of the diagnostic modalities: Voiding cystouretrography (VCUG), Sonouretrography (SUG) or Magnetic resonance uretrography (MRU) is the most accurate in the assessment of urethral strictures in males and in what cases the application of novel imaging techniques benefits most., Methods: 55 male patients with a diagnosis of urethral stricture, were enrolled in this prospective study. Initial diagnosis of urethral stricture was based on anamnesis, uroflowmetry and VCUG. Additional imaging procedures-SUG and MRU were performed before the surgery. Virtual models and 3D printed models of the urethra with the stricture were created based on the MRU data. Exact stricture length and location were evaluated by each radiological method and accuracy was verified intraoperatively. Agreement between SUG and MRU assessments of spongiofibrosis was evaluated. MRU images were independently interpreted by two radiologists (MRU 1, MRU 2) and rater reliability was calculated., Results: MRU was the most accurate [(95% CI 0.786-0.882), p < 0.0005] with an average overestimation of 1.145 mm (MRU 1) and 0.727 mm (MRU 2) as compared with the operative measure. VCUG was less accurate [(95% CI 0.536-0.769), p < 0.0005] with an average underestimation of 1.509 mm as compared with operative measure. SUG was the least accurate method [(95% CI 0.510-0.776), p < 0.0005] with an average overestimation of 2.127 mm as compared with the operative measure. There was almost perfect agreement of MRU interpretations between the radiologists., Conclusions: VCUG is still considered as a 'gold standard' in diagnosing urethral stricture disease despite its limitations. SUG and MRU provide extra guidance in preoperative planning and should be considered as supplemental for diagnosing urethral stricture. Combination of VCUG and SUG may be an optimal set of radiological tools for diagnosing patients with urethral strictures located in the penile urethra. MRU is the most accurate method and should particularly be considered in cases of post-traumatic or multiple strictures and strictures located in the posterior urethra., (© 2021. The Author(s).)

Purpose: To determine the diagnostic yield of computed tomography urography (CTU) in patients evaluated for hematuria with negative cystoscopy and to assess the added value of CTU when compared with ultrasound (US) in this patient population., Methods: A retrospective study was conducted of patients who underwent CTU within 12 months of negative cystoscopy for workup of hematuria at our institution from January 2016 to December 2017. Computed tomography urography findings were recorded and compared to clinical diagnoses to determine diagnostic yield. Computed tomography urography and US findings were compared in patients who underwent both examinations. Patient characteristics (age, sex, smoking history, and hematuria subtype) were reported., Results: A total of 657 patients met the inclusion criteria, including 108 patients aged 50 years and younger. No cause for hematuria was identified in 41% of patients overall and 58% of patients aged 50 years and younger. The most common diagnoses were benign prostatic hyperplasia and urolithiasis, accounting for 25% and 21% of patients, respectively; 0.6% of patients were diagnosed with an upper urinary tract malignancy, all older than 50 years. Although US was superior or equal to CTU for diagnosis in 83% of patients who underwent both examinations, US had a 0% sensitivity for detection of upper urinary tract malignancy., Conclusion: The low diagnostic yield of CTU and low prevalence of upper urinary tract malignancy in patients evaluated for hematuria with negative cystoscopy, particularly those aged 50 years and younger, call into question the appropriateness of multiphasic CTU as a first-line imaging modality in this population.