A novel model of artificial intelligence based automated image analysis of CT urography to identify bladder cancer in patients investigated for macroscopic hematuria

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.

Non-contrast-enhanced magnetic resonance urography for measuring split kidney function in pediatric patients with hydronephrosis: comparison with renal scintigraphy

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.

Quantification of vesicoureteral reflux using machine learning

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.

Evaluation of differential renal function in children - a comparative study between magnetic resonance urography and dynamic renal scintigraphy

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.

Estimation of renal function using iodine maps in dual-energy spectral computed tomography urography: a feasibility and accuracy study

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-GFRiodine) and 120 kVp-like images (CT-GFR120kvp) separately. CT-GFRiodine and CT-GFR120kvp 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-GFR120kvp and CT-GFRiodine.

RESULTS

The difference between eGFR (89.91 ± 18.45 ml·min-1·1.73 m-2) as reference standard and CT-GFRiodine (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-GFR120kvp (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-GFRiodine 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.

Low-dose versus conventional CT urography using dual-source CT with different time-current product values and the same tube voltage: image quality and diagnostic performance in various diagnoses

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.

Discrepant guidelines in the evaluation of hematuria

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.

Evaluation of image quality and radiation dose in computed tomography urography following tube voltage optimisation

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.

Detection and characterization of urinary stones using material-specific images derived from contrast-enhanced dual-energy CT urography

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_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.

Decreased percent change in renal pelvis diameter on diuretic functional magnetic resonance urography following administration of furosemide may help characterize unilateral uretero-pelvic junction obstruction

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.

Functional MR urography in children - update 2023

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.

Application of contrast-enhanced ultrasound in the surgical treatment of vesicoureteral reflux in children

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.

Toward the Deimplementation of Computed Tomography Urogram for Patients With Low- to Intermediate-risk Microscopic Hematuria: A Mixed-method Study of Factors Influencing Continued Use

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.

Cine magnetic resonance urography as a new approach for postoperative evaluation of the reconstructed upper urinary tract: a multicenter study

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 m2, failure: 61.6 ± 14.1 mL/min·1.73 m2, P = 0.014; gray area: 94.7 ± 24.6 mL/min·1.73 m2, failure: 61.6 ± 14.1 mL/min·1.73 m2, 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.

Essentials of Computed Tomography Imaging of Hematuria

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.

Manifestation of Urinary Tract Injury during Cervical Cancer Surgery Based on CT Urography Secretion Phase Images

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.

Urinary Tract Infections in Young Children and Infants: Common Questions and Answers

Urinary tract infections (UTIs) are common in children and are associated with significant short- and long-term morbidity. They have a high recurrence rate and are associated with anatomic and functional abnormalities. The decision to test for UTI is based on risk factors and the child's age. Urinalysis is valuable to rule out UTI and to help decide when to start antibiotics; however, urine culture is needed for definitive diagnosis. Urine specimens collected via perineal bagging should not be used for culture because of high false-positive rates. Diagnosis of UTI requires pyuria and bacterial growth in the urine culture. Prompt treatment of UTIs reduces renal scarring. Antibiotic selection should be based on local sensitivity patterns and adjusted once culture results are available. In most cases, oral antibiotics are as effective as intravenous agents. When intravenous antibiotics are used, early transition to an oral regimen is as effective as longer intravenous courses. Kidney and bladder ultrasonography is helpful to identify acute complications and anatomic abnormalities. Voiding cystourethrography is indicated when ultrasound findings are abnormal and in cases of recurrent febrile UTIs. The use of antibiotic prophylaxis for recurrent UTIs is controversial. Identification and treatment of bowel and bladder dysfunction can prevent UTI recurrence.

IDEAL study: magnetic resonance imaging for suspected deep endometriosis assessment prior to laparoscopy is as reliable as radiological imaging as a complement to transvaginal ultrasonography

OBJECTIVE

To compare the value of using one-stop magnetic resonance imaging (MRI) vs standard radiological imaging as a supplement to transvaginal ultrasonography (TVS) for the preoperative assessment of patients with endometriosis referred for surgery in a tertiary care academic center.

METHODS

This prospective observational study compared the diagnostic value of the standard preoperative imaging practice of our center, which involves expert TVS complemented by intravenous urography (IVU) for the evaluation of the ureters and double-contrast barium enema (DCBE) for the evaluation of the rectum, sigmoid and cecum, with that of expert TVS complemented by a 'one-stop' MRI examination evaluating the upper abdomen, pelvis, kidneys and ureters as well as rectum and sigmoid on the same day, for the preoperative triaging of 74 women with clinically suspected deep endometriosis. The findings at laparoscopy were considered the reference standard. Patients were stratified according to their need for monodisciplinary surgical approach, carried out by gynecologists only, or multidisciplinary surgical approach, involving abdominal surgeons and/or urologists, based on the extent to which endometriosis affected the reproductive organs, bowel, ureters, bladder or other abdominal organs.

RESULTS

Our standard preoperative imaging approach and the combined findings of TVS and MRI had similar diagnostic performance, resulting in correct stratification for a monodisciplinary or a multidisciplinary surgical approach of 67/74 (90.5%) patients. However, there were differences between the estimation of the severity of disease by DCBE and MRI. The severity of rectal involvement was underestimated in 2.7% of the patients by both TVS and DCBE, whereas it was overestimated in 6.8% of the patients by TVS and/or DCBE.

CONCLUSIONS

Complementary to expert TVS, 'one-stop' MRI can predict intraoperative findings equally well as standard radiological imaging (IVU and DCBE) in patients referred for endometriosis surgery in a tertiary care academic center. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

The Importance of Cystoscopy in Diagnosis and Treatment of Urethral Stricture Following Transurethral Prostatectomy

BACKGROUND

Transurethral prostatectomy is the gold standard surgical treatment of bladder outlet obstruction due to benign enlargement of the prostate, with more than 30,000 procedures performed annually in the United States alone. The success rate of this minimally invasive procedure is high and the results are durable. The development of urethral stricture is a long-term complication of the procedure and is noted in about 2% of patients. The stricture narrows the urethral lumen, leading to re-appearance of obstructive urinary symptoms. Traditionally, the evaluation of the stricture was performed by retrograde urethrography. Advancements in the fields of flexible endoscopy allowed rapid inspection of the urethra and immediate dilatation of the stricture in selected cases.

OBJECTIVES

To compare the efficacy of urethrography versus cystoscopy in the evaluation of urethral strictures following transurethral prostatectomy.

METHODS

A retrospective review was conducted of a series of 32 consecutive patients treated due to post-transurethral resection of prostate (TURP) urethral stricture.

RESULTS

Twenty patients underwent both tests. In 16 there was concordance between the two tests. Four patients had no pathological findings in urethrography but had strictures in cystoscopy. All strictures were short (up to 10 mm) and were easily treated during cystoscopy, with no complaints or re-surgery needed in 24 months follow-up.

CONCLUSIONS

Cystoscopy was superior to urethrography in the evaluation of post-TURP strictures. Strictures where often short and treated during the same procedure. We recommend that cystoscopy be the procedure of choice in evaluating obstructive urinary symptoms after TURP, and retrograde urethrography be preserved for selected cases.

Safety of retrograde pyelography for infected ureteral stones

INTRODUCTION

Initial management of obstructing ureteral stones with concomitant urinary tract infection (UTI) includes prompt renal decompression and antibiotics. Some urologists theorize that performing retrograde pyelography (RGP) at the time of ureteral stent placement may cause pyelovenous backflow of bacteria thereby worsening clinical outcomes. We compared outcomes in patients with infected ureteral stones who underwent RGP versus no RGP prior to stent placement.

MATERIALS AND METHODS

A retrospective chart review was conducted involving patients who presented between 2015 and 2017 with an obstructing ureteral stone and associated UTI. Computed tomography scans were evaluated for stone size and location. Operative reports were reviewed to determine whether the patient underwent RGP at time of ureteral stent placement. Demographics, perioperative information, intensive care unit (ICU) admission rate, and length of stay (LOS) were compared.

RESULTS

Seventy-two patients were identified and stratified by severity of condition at presentation, including UTI without sepsis (n = 18), sepsis (n = 32), severe sepsis (n = 11), and septic shock (n = 11). Forty-three patients underwent RGP at the time of stent placement, and 29 did not. Between both patient cohorts, statistical analysis revealed no significant difference in postoperative ICU admission rate (p = 0.35) or LOS for patients with UTI without sepsis (p = 0.17), sepsis (p = 0.45), severe sepsis (p = 0.66), and septic shock (p = 0.25).

CONCLUSION

The use of RGP prior to ureteral stent placement for an obstructing ureteral stone with concomitant UTI was not associated with unfavorable clinical outcomes in our retrospective series. While these findings support the safety of RGP in this setting, prospective trials are warranted.

Imaging protocols for renal multiparametric MRI and MR urography: results of a consensus conference from the French Society of Genitourinary Imaging

OBJECTIVES

To develop technical guidelines for magnetic resonance imaging aimed at characterising renal masses (multiparametric magnetic resonance imaging, mpMRI) and at imaging the bladder and upper urinary tract (magnetic resonance urography, MRU).

METHODS

The French Society of Genitourinary Imaging organised a Delphi consensus conference with a two-round Delphi survey followed by a face-to-face meeting. Two separate questionnaires were issued for renal mpMRI and for MRU. Consensus was strictly defined using a priori criteria.

RESULTS

Forty-two expert uroradiologists completed both survey rounds with no attrition between the rounds. Fifty-six of 84 (67%) statements of the mpMRI questionnaire and 44/71 (62%) statements of the MRU questionnaire reached final consensus. For mpMRI, there was consensus that no injection of furosemide was needed and that the imaging protocol should include T2-weighted imaging, dual chemical shift imaging, diffusion-weighted imaging (use of multiple b-values; maximal b-value, 1000 s/mm²) and fat-saturated single-bolus multiphase (unenhanced, corticomedullary, nephrographic) contrast-enhanced imaging; late imaging (more than 10 min after injection) was judged optional. For MRU, the patients should void their bladder before the examination. The protocol must include T2-weighted imaging, anatomical fast T1/T2-weighted imaging, diffusion-weighted imaging (use of multiple b-values; maximal b-value, 1000 s/mm²) and fat-saturated single-bolus multiphase (unenhanced, corticomedullary, nephrographic, excretory) contrast-enhanced imaging. An intravenous injection of furosemide is mandatory before the injection of contrast medium. Heavily T2-weighted cholangiopancreatography-like imaging was judged optional.

CONCLUSION

This expert-based consensus conference provides recommendations to standardise magnetic resonance imaging of kidneys, ureter and bladder.

KEY POINTS

• Multiparametric magnetic resonance imaging (mpMRI) aims at characterising renal masses; magnetic resonance urography (MRU) aims at imaging the urinary bladder and the collecting systems. • For mpMRI, no injection of furosemide is needed. • For MRU, an intravenous injection of furosemide is mandatory before the injection of contrast medium; heavily T2-weighted cholangiopancreatography-like imaging is optional.

Imaging protocols for CT urography: results of a consensus conference from the French Society of Genitourinary Imaging

OBJECTIVES

To develop technical guidelines for computed tomography urography.

METHODS

The French Society of Genitourinary Imaging organised a Delphi consensus conference with a two-round Delphi survey followed by a face-to-face meeting. Consensus was strictly defined using a priori criteria.

RESULTS

Forty-two expert uro-radiologists completed both survey rounds with no attrition between the rounds. Ninety-six (70%) of the initial 138 statements of the questionnaire achieved final consensus. An intravenous injection of 20 mg of furosemide before iodinated contrast medium injection was judged mandatory. Improving the quality of excretory phase imaging through oral or intravenous hydration of the patient or through the use of an abdominal compression device was not deemed necessary. The patient should be imaged in the supine position and placed in the prone position only at the radiologist's request. The choice between single-bolus and split-bolus protocols depends on the context, but split-bolus protocols should be favoured whenever possible to decrease patient irradiation. Repeated single-slice test acquisitions should not be performed to decide of the timing of excretory phase imaging; instead, excretory phase imaging should be performed 7 min after the injection of the contrast medium. The optimal combination of unenhanced, corticomedullary phase and nephrographic phase imaging depends on the context; suggestions of protocols are provided for eight different clinical situations.

CONCLUSION

This expert-based consensus conference provides recommendations to standardise the imaging protocol for computed tomography urography.

KEY POINTS

• To improve excretory phase imaging, an intravenous injection of furosemide should be performed before the injection of iodinated contrast medium. • Systematic oral or intravenous hydration is not necessary to improve excretory phase imaging. • The choice between single-bolus and split-bolus protocols depends on the context, but split-bolus protocols should be favoured whenever possible to decrease patient irradiation.

[Use of volumetric dynamic voiding multispiral computed cystourethrography in diagnosis and evaluation of treatment efficiency of congenital and acquired pathology of the urogenital area]

AIM

The aim of this study was to determine the possibilities of volumetric dynamic voiding multispiral computed cystourethrography (VDMMCT) for assessment of the lower urinary tract during voiding.

MATERIALS AND METHODS

VDMMCT was performed in a series of 22 patients with various urethral pathologies using 320 detector rows (640 unique slices; row width 0,5 mm). This method allows to cover the scan area of 16 cm per one rotation of the X-ray tube. In all patients, the cross-sectional area of the various urethral parts was estimated and the urinary bladder volume and average urine flow rate during all voiding phases were calculated.

RESULTS

VDMMCT was performed for dynamic evaluation of bladder volumes changes and analyzing a passage of contrasted urine throughout the urethra. The average volume of the urinary bladder was 356.3+/-179.9 ml, while the voiding volume was 299.5+/-154.8 ml. The average pre- and postoperative urine flow rate was 4.1+/-1.1 ml/s and 7.9+/-5.1 ml/s, respectively. The maximum urine flow rate was 19 ml/s. The average urethral diameter according to the VDMMCT after urethroplasty was 7.6+/-2.1 mm. The minimum length of urethral strictures was 17 mm, while the maximum length was 32 mm.

CONCLUSION

Our results demonstrate the efficiency of the VDMMCT for assessing of the urethra throughout its length. VDMMCT can multidimensionally and dynamically represent the change of the bladder volume and the urine flow rate.

What a difference a delay makes! CT urogram: a pictorial essay

PURPOSE

The aim of this pictorial essay is to demonstrate several cases where the diagnosis would have been difficult or impossible without the excretory phase image of CT urography.

METHODS

A brief discussion of CT urography technique and dose reduction is followed by several cases illustrating the utility of CT urography.

RESULTS

CT urography has become the primary imaging modality for evaluation of hematuria, as well as in the staging and surveillance of urinary tract malignancies. CT urography includes a non-contrast phase and contrast-enhanced nephrographic and excretory (delayed) phases. While the three phases add to the diagnostic ability of CT urography, it also adds potential patient radiation dose. Several techniques including automatic exposure control, iterative reconstruction algorithms, higher noise tolerance, and split-bolus have been successfully used to mitigate dose. The excretory phase is timed such that the excreted contrast opacifies the urinary collecting system and allows for greater detection of filling defects or other abnormalities. Sixteen cases illustrating the utility of excretory phase imaging are reviewed.

CONCLUSIONS

Excretory phase imaging of CT urography can be an essential tool for detecting and appropriately characterizing urinary tract malignancies, renal papillary and medullary abnormalities, CT radiolucent stones, congenital abnormalities, certain chronic inflammatory conditions, and perinephric collections.

CT urography: how to optimize the technique

PURPOSE

Computed tomography urography (CTU) has emerged as the modality of choice for imaging the urinary tract within the past few decades. It is a powerful tool that enables detailed anatomic evaluation of the urinary tract in order to identify primary urothelial malignancies, benign urinary tract conditions, and associated abdominopelvic pathologies. As such, there have been extensive efforts to optimize CTU protocol.

METHODS

This article reviews the published literature on CTU protocol optimization, including contrast bolus timing, dose reduction, reconstruction algorithms, and ancillary practices.

CONCLUSION

There have been many advances in CTU techniques, which allow for imaging diagnosis of a wide spectrum of diseases while minimizing radiation dose and maximizing urinary tract distension and opacification.

Crossed-fused renal ectopia with renal calculi: Two case reports and a review of the literature

RATIONALE

Crossed renal ectopia (CRE) is a rare congenital anomaly that is frequently associated with gastrointestinal, cardiovascular, genital and bone malformations. To the best of our knowledge, only 35 cases of crossed renal ectopia involving calculi and 30 cases of CRE associated with renal carcinoma have been reported to date.

PATIENT CONCERNS

Here, we present 2 cases of crossed renal ectopia. A 59-year-old woman with diabetes presented to our hospital with abdominal pain. The second patient was a 24-year-old woman who complained with abdominal pain with a duration of 1 day.

DIAGNOSES

On the basis of abdominal ultrasonography, we suspected a solitary kidney both in the two patients. Combined with retrograde pyelography and 3D computed tomography, case 1 was diagnosed as an S-shaped right-to-left crossed-fused ectopic kidney with many stones in the left (normal) renal pelvis and case 2 was confirmed to have lump right-to-left crossed-fused renal ectopia with two 3-mm stones in the renal pelvis of the 2 kidneys.

INTERVENTIONS

Case 1 underwent percutaneous nephrolithotomy while case 2 refused to undergo surgery and underwent conservative treatment for pain relief.

OUTCOMES

Two patients have been followed up and have no stones recurrence.

LESSONS

Crossed fused renal ectopia is easily misdiagnosed as a solitary kidney. CRE is so rare that the recognition of the disease needs to be improved and effective treatment should be taken timely. According to the two cases and literature review, minimally invasive surgery has become increasingly common to treat CRE with stones and carcinoma.

Effect of using immobilization device in fluoroscopic study in pediatric patient: Focused on radiation dose reduction in voiding cystourethrogram

Introduction

To prove objective effect of using mechanical device for immobilization of pediatric patient during voiding cystourethrogram (VCUG) compare immobilization by hand-holding.

Methods

This study included 77 patients, who underwent VCUG in our center from April to October 2017, who had a clinically suspicious urinary tract infection. Patients were classified into one of two groups based on whether examination was done before (Group A) or after (Group B) adaptation of immobilization device. Patient-related data, image quality related score and dose-related data were collected and compared between two groups.

Results

Group A included 36 patients and group B included 41. Patient related data including mean age, sex, body weight and height didn’t show significant difference between two groups (p > 0.05 for all). Among the image quality scoring, overall image quality, motion artifact, showed significant difference between two groups with improved inadequate timing and centering after adaptation of immobilization device. Dose related data showed significantly decreased shot number, mean fluoroscopic time with decreased mean dose area product (DAP) value and effective dose after adaptation of immobilization device (p < 0.05 for all).

Conclusion

Adaptation of immobilization device can improve overall image quality with decreased motion artifact and improved centering and timing with even shot number, mean fluoroscopic time with decreased mean DAP value and effective dose.

Clinical Spectrum of Congenital Anomalies of Kidney and Urinary Tract in Children

OBJECTIVES

To evaluate the clinical spectrum and patterns of clinical presentation in congenital anomalies of kidney and urinary tract.

METHODS

We enrolled 307 consecutively presenting children with congenital anomalies of kidney and urinary tract at the pediatric nephrology clinic. Patients were evaluated clinically, with serum biochemistry, appropriate imaging and radionuclide scans.

RESULTS

The most common anomaly was primary vesicoureteric reflux (VUR) (87, 27.3%), followed by pelviureteral junction obstruction (PUJO) (62,20.1%), multicystic dysplastic kidney (51 16.6%), non-obstructive hydronephrosis (32, 10.4%) and posterior urethral valves (PUV) (23, 7.4%). 247 (80.4%) anomalies had been identified during the antenatal period. Another 33 (10.7%) were diagnosed during evaluation of urinary tract infection, and 21 (6.8%) during evaluation for hypertension at presentation. Obstructive anomalies presented earlier than non-obstructive (7 (3, 22.5) vs 10 (4, 24) mo: (P=0.01)). The median (IQR) ages of presentation for children with PUV (n=23), VUR (n=87) and PUJO (n=62) were 4 (2, 14) mo, 10 (5, 27) mo, and 7 (3, 22.5) mo, respectively. Nine (2.9%) children had extrarenal manifestations.

CONCLUSIONS

The median age at clinical presentation for various subgroups of anomalies indicates delayed referral. We emphasize the need for prompt referral in order to initiate appropriate therapeutic strategies in children with congenital anomalies of kidney and urinary tract.

Deep Learning Approach for Assessment of Bladder Cancer Treatment Response

We compared the performance of different Deep learning-convolutional neural network (DL-CNN) models for bladder cancer treatment response assessment based on transfer learning by freezing different DL-CNN layers and varying the DL-CNN structure. Pre- and posttreatment computed tomography scans of 123 patients (cancers, 129; pre- and posttreatment cancer pairs, 158) undergoing chemotherapy were collected. After chemotherapy 33% of patients had T0 stage cancer (complete response). Regions of interest in pre- and posttreatment scans were extracted from the segmented lesions and combined into hybrid pre -post image pairs (h-ROIs). Training (pairs, 94; h-ROIs, 6209), validation (10 pairs) and test sets (54 pairs) were obtained. The DL-CNN consisted of 2 convolution (C1-C2), 2 locally connected (L3-L4), and 1 fully connected layers. The DL-CNN was trained with h-ROIs to classify cancers as fully responding (stage T0) or not fully responding to chemotherapy. Two radiologists provided lesion likelihood of being stage T0 posttreatment. The test area under the ROC curve (AUC) was 0.73 for T0 prediction by the base DL-CNN structure with randomly initialized weights. The base DL-CNN structure with pretrained weights and transfer learning (no frozen layers) achieved test AUC of 0.79. The test AUCs for 3 modified DL-CNN structures (different C1-C2 max pooling filter sizes, strides, and padding, with transfer learning) were 0.72, 0.86, and 0.69. For the base DL-CNN with (C1) frozen, (C1-C2) frozen, and (C1-C2-L3) frozen, the test AUCs were 0.81, 0.78, and 0.71, respectively. The radiologists' AUCs were 0.76 and 0.77. DL-CNN performed better with pretrained than randomly initialized weights.

The anatomy of the renal pyelocaliceal system studied by CTU

INTRODUCTION AND OBJECTIVES

Knowledge of the pyelocaliceal system anatomy is essential for the safe and successful performance of endourologic procedures. The purpose of this study was to provide a better understanding of the full three-dimensional pyelocaliceal system anatomy.

METHODS

Morphometric parameters of the three-dimensional reconstructions of computed tomography intravenous urography scans (n = 25 scans) were analyzed. Both kidneys were divided into three equal-sized segments (US: upper segment, MS: mid segment, LS: lower segment). Infundibular length (IL), infundibular width (IW), the number of calyces, and the transverse orientation in hours of a clock of each calyx as well as the dimension of the pyelum were determined.

RESULTS

The mean upper IL (n = 92) was longer than the middle (n = 154) and lower IL (n = 112) (30.6 ± 7.9 mm vs. 16.4 ± 7.7 mm vs. 16.0 ± 6.0 mm, respectively; P = < 0.0001). IW was significantly smaller in the MS [3.7 ± 1.9 mm], followed by the US [4.6 ± 1.9 mm], and the LS [4.9 ± 2.2] in the increasing order. No correlation was found between IL and IW (Pearson correlation coefficient = 0.1). The US calyces were predominantly orientated lateral (8-10 o'clock: 44.5%) and medial (2-4 o'clock: 30.5%), in the MS lateral (8-10 o'clock: 87.6%) and anterolateral in the LS (9-12 o'clock: 67.9%). 74% of the kidneys consisted of 6-8 calyces (mean 7.2 ± 1.4, range 4-10), with the majority of the calyces in the MS (3.1 ± 0.8) followed by the LS (2.24 ± 0.8), and US (1.8 ± 0.7). There were no statistical differences between the right and left kidneys in terms of IL (P = 0.112) and number of calyces (P = 0.685).

CONCLUSION

Anatomic differences between the three segments of the pyelocaliceal system in terms of IL, IW, calyces number, and orientation are seen and should be considered when performing an endourologic procedure.

Rare case with plethora of upper urinary tract anomalies associated with pelviureteric junction obstruction: a surgical challenge managed with robot assistance

The genitourinary system for reasons unknown is more likely to have birth defects than any other system. The anomaly of collecting system draining the kidney represent mystifying subset of congenital anomalies. Pelviureteric junction obstruction (PUJO) is most common. Chronic obstruction can lead to stasis, urinary infection and stone formation in PUJO. Extrarenal calyces, which is characterised by presence of calyces and renal pelvis outside the renal parenchyma is one of the rare anomalies seen among the collecting system right gonadal vein drains into inferior vena cava. Its altered drainage into right renal vein is rarely seen and reported. Glut of these multiple anomalies in a single case is an extremely rare event. We hereby discuss a case of 40-year-old male patient with combination of all these anomalies and discuss the embryology, presentation and management.

Ureteral dilatation detected in magnetic resonance imaging predicts vesicoureteral reflux in children with urinary tract infection

Objective

Urinary tract infection (UTI), one of the most common bacterial infections occurring during infancy and early childhood, is frequently associated with vesicoureteral reflux (VUR). Although several guidelines recommend performing ultrasonography as a screening test, its utility is not adequate and appropriate screening tests are strongly desirable. In this study, we evaluate the use of magnetic resonance imaging (MRI) as a screening test for VUR in children with UTI.

Methods

We prospectively studied 108 patients with suspected UTI between April 2014 and March 2016. UTI was diagnosed on the basis of diffusion-weighted MRI (DW-MRI) and urine culture findings. We measured ureteral dilatation using MRI in 96 patients with UTI and assessed the relationship between ureteral dilatation in MRI and VUR in 46 patients who underwent voiding cystourethrography (VCUG).

Results

Among 108 patients, 88 and 8 were diagnosed with upper and lower UTI, respectively. Among 46 patients who underwent VCUG, 23 had VUR (14 low grade and 9 high grade). Patients with ureteral dilatation detected on MRI had VUR more frequently than those without ureteral dilatation (any grades VUR, 71% vs. 32%; P = 0.02; high-grade VUR, 38% vs. 2%, P = 0.007). Overall, ureteral dilatation findings on MRI achieved sensitivity 65.2% and specificity 73.9% as a screening test for VUR. In addition, DW-MRI achieved sensitivity 100% and specificity 81.8% in the diagnosis of upper UTI.

Conclusion

These findings suggested that MRI is a valuable tool for screening of VUR as well as diagnosis of upper UTI.

Anatomic Relationship Between Ureter and Oblique Lateral Interbody Fusion Access: Analysis Based on Contrast-Enhanced Computed Tomographic Urography

OBJECTIVE

To investigate the anatomic relationship between ureter and oblique lateral interbody fusion access by using contrast-enhanced computed tomographic urography.

METHODS

Contrast-enhanced computed tomographic urography data of 234 patients were retrospectively analyzed. The angle of inclination (∠α) of bilateral ureters, the angle between bilateral surgical accesses (∠β), the insertion angle of surgical access (∠γ), and the angle between ureter and outer margin of ipsilateral surgical access (∠ε) at L2/3, L3/4, and L4/5 levels were measured and analyzed.

RESULTS

∠α gradually increased from L2/3 to L4/5. ∠β gradually decreased from L2/3 to L4/5, and at each level the left-sided ∠β was larger than right-sided ∠β. ∠ε were positive at L2/3 and left-sided L3/4. The right-sided ∠ε at L3/4 and the bilateral sided ∠ε at L4/5 were negative, and the right-sided ∠ε at L4/5 had the largest absolute value.

CONCLUSIONS

The bilateral ureters gradually descents from the lateral margin to the anteromedial margin on the surface of psoas major muscle. The range of bilateral surgical accesses for oblique lateral interbody fusion gradually decreases from L2/3 to L4/5, and the left-sided access is larger than the right-sided when at the same level. Ureters at the right-sided L3/4 level and bilateral L4/5 levels are at high risk of being injured. In particular, the right ureter at the L4/5 level is most likely to be injured.

Postnatal imaging of prenatally detected hydronephrosis-when is voiding cystourethrogram necessary?

OBJECTIVE

To evaluate whether grade 4-5 vesicoureteral reflux (VUR) can be predicted from renal ultrasound (RUS) findings and perform voiding cystourethrograms (VCUGs) only on high-risk patients.

METHODS

The RUS and VCUG images of infants with prenatally detected hydronephrosis admitted to our institution between 2003 and 2013 were re-evaluated. The UTI episodes were collected retrospectively from patient journals. Patients with complex urinary tract anomalies were excluded.

RESULTS

One hundred eighty, 44 female and 136 male, patients (352 renal units (RU)), 23 (30 RU) of them having grade 4-5 VUR, were included. The median age of the patients at the time of the RUS was 1.3 (0.1-3.0) months and the median follow-up time was 2.0 (0.1-11.2) years. In multivariate analysis, a visible ureter (OR 12.72; CI 5.33-32.04, p < 0.001) and shorter renal length (OR 2.67; CR 1.50-4.86, p < 0.001) in RUS predicted grade 4-5 VUR while a visible ureter predicted UTIs (OR 5.75; CI 2.59-12.66, p < 0.001). A three-grade risk score for high-grade VUR was developed based on the RUS findings and the patients were categorized into low-, intermediate-, and high-risk groups. The incidence of grade 4-5 VUR was 2.9% in the low-risk, 12.2% in the intermediate-risk, and 52.2% in the high-risk group. The sensitivity and specificity for detecting grade 4-5 VUR were 79 and 82%, respectively.

CONCLUSIONS

In patients with antenatally detected hydronephrosis, a visible ureter and reduced renal length in RUS are significant risk factors for high-grade VUR. A RUS-based risk scoring would probably reduce the proportion of unnecessary VCUGs.

Bladder cancer diagnosis with CT urography: test characteristics and reasons for false-positive and false-negative results

PURPOSE

To determine test characteristics of CT urography for detecting bladder cancer in patients with hematuria and those undergoing surveillance, and to analyze reasons for false-positive and false-negative results.

METHODS

A HIPAA-compliant, IRB-approved retrospective review of reports from 1623 CT urograms between 10/2010 and 12/31/2013 was performed. 710 examinations for hematuria or bladder cancer history were compared to cystoscopy performed within 6 months. Reference standard was surgical pathology or 1-year minimum clinical follow-up. False-positive and false-negative examinations were reviewed to determine reasons for errors.

RESULTS

Ninety-five bladder cancers were detected. CT urography accuracy: was 91.5% (650/710), sensitivity 86.3% (82/95), specificity 92.4% (568/615), positive predictive value 63.6% (82/129), and negative predictive value was 97.8% (568/581). Of 43 false positives, the majority of interpretation errors were due to benign prostatic hyperplasia (n = 12), trabeculated bladder (n = 9), and treatment changes (n = 8). Other causes include blood clots, mistaken normal anatomy, infectious/inflammatory changes, or had no cystoscopic correlate. Of 13 false negatives, 11 were due to technique, one to a large urinary residual, one to artifact. There were no errors in perception.

CONCLUSION

CT urography is an accurate test for diagnosing bladder cancer; however, in protocols relying predominantly on excretory phase images, overall sensitivity remains insufficient to obviate cystoscopy. Awareness of bladder cancer mimics may reduce false-positive results. Improvements in CTU technique may reduce false-negative results.

Urethral Rest with Suprapubic Cystostomy for Obliterative or Nearly Obliterative Urethral Strictures: Urethrographic Changes and Implications for Management

PURPOSE

Precise preoperative characterization of urethral stricture is important for surgical planning. A period of urethral rest by a suprapubic cystostomy tube may aid in stricture characterization and affect the surgical approach. In this study fellowship trained reconstructive urologists compared the radiographic characterization of anterior urethral strictures before and after a period of urethral rest. We then determined how this changed the planned operative approach.

MATERIALS AND METHODS

We queried our prospectively maintained urethroplasty database at our institution for men with an anterior urethral stricture who underwent retrograde urethrogram and voiding cystourethrogram before and after preoperative suprapubic cystostomy tube placement. A total of 29 men were identified for analysis. To minimize responder fatigue 20 pairs of radiographs were selected at random. All images before and after suprapubic tube placement were interpreted in random order by 11 fellowship trained reconstructive urologists. Interpretation included stricture length, diameter, location and surgeon operative plan. Preplacement and post-placement results were compared. Post-placement stricture length was also compared to intraoperative length. ICC was used to evaluate homogeneity among the urologists. Linear regression analysis was performed to determine the association of post-radiographic length after tube placement with intraoperative stricture length.

RESULTS

Imaging agreement among interpreting urologists was satisfactory (ICC 0.72). There was no statistically significant difference in stricture length before vs after suprapubic tube placement. Of the images 23% were considered obliterative before tube placement while 58% were obliterative after placement (p = 0.0005). Mean ± SD post-placement radiographic and intraoperative stricture length was 3.0 ± 2.6 and 3.8 ± 3.3 cm, respectively (p <0.0001). Deviation between the radiographic and intraoperative lengths increased with stricture length (slope 0.26, p = 0.0023). The surgeon operative plan changed 47% of the time, including to an excision approach in 37% of cases.

CONCLUSIONS

Despite optimal urethral imaging with a suprapubic tube in men with high grade stricture reconstructive urologists underestimated length by an average of almost 1 cm. This underestimation was less for shorter strictures and it increased with stricture length. In addition, a period of urethral rest resulted in more frequent stricture obliteration, which was associated with a change in the planned operative approach about half of the time. If urologists do not place a suprapubic cystostomy tube prior to urethroplasty for high grade stricture, the operative plan should account for the stricture being tighter than it may appear.

Multidetector CT urography in urogenital tuberculosis: use of reformatted images for the assessment of the radiological findings. A pictorial essay

Urogenital tuberculosis (UGTB) is the most common form of extrapulmonary TB and is responsible for a destructive inflammation of the renal parenchyma and urinary tract often leading to the loss of kidney function. For these reasons, the early diagnosis of this disease, once considered disappeared in developed countries, is very important to establish a prompt and efficient treatment. However, the subtle and non-specific symptoms, often represented by recurrent and persistent lower urinary tract symptoms, can confound and delay the diagnosis. Therefore, an adequate and comprehensive imaging study is necessary in patients with persistent urinary tract infections not responding to the antibiotics and can suggest the hypothesis although bacteriological and/or histologic analysis is required for a definitive diagnosis. In the past years, intravenous urography (IVU) has allowed a comprehensive study of the urinary excretory tract, promoting the knowledge of the radiological findings of this disease. Nowadays, computed tomography urography (CTU), with the implementation of multidetector (MD) technology, has replaced IVU in all its indications; the MDCTU improves the assessment of renal and urinary tract lesions using reformatted images [such as multiplanar reconstruction (MPR) and maximum intensity projection (MIP)]. Therefore, our paper aims to provide a guide for radiologist for searching the classic signs of UGTB on MDCTU, encouraging the use of the MPR and MIP reformatted images.

Dose reduction in CT urography and vasculature phantom studies using model-based iterative reconstruction

To evaluate the feasibility of radiation dose reduction using model-based iterative reconstruction (MBIR) for evaluating the ureters and vasculature in a phantom, a tissue-equivalent CT dose phantom was scanned using a 64-channel CT scan-ner. Tubes of varying diameters filled with different dilutions of a contrast agent, simulating ureters or vessels, were inserted into the center of the phantom. Each combination was scanned using an existing renal protocol at 140 kVp or 120 kVp, yielding a display volumetric CT dose index (CTDIvol) of 24 mGy. The scans were repeated using reduced scan techniques to achieve lower radiation doses down to 0.8 mGy. The images were reconstructed using filtered back-projection (FBP) and model-based iterative reconstruction (MBIR). The noise and contrast-to-noise ratio (CNR) was measured for each contrast object. Comparisons between the two reconstruction methods at different dose levels were evaluated using a factorial design. At each CTDIvol the measured image noise was lower using MBIR compared to FBP (p < 0.0001). At low doses, the percent change in measured image noise between FBP and MBIR was larger. For the 12 mm object simulating a ureter or large vessel with an HU of 600, the measured CNR using MBIR at a CTDIvol of 1.7 mGy was greater than the CNR of FBP at a CTIDvol of 24 mGy (p < 0.0001). For the 5 mm object simulating a medium-sized vessel with a HU of 250, the mea-sured CNR using MBIR at a CTDIvol of 1.7 mGy was equivalent to that of FBP at a CTDIvol of 24 mGy. For the 2 mm, 100 HU object simulating a small vessel, the measured CNR using MBIR at a CTDIvol of 1.7 mGy was equivalent to that of FBP at a CTDIvol of 24 mGy. Low-dose (3.6 mGy) CT imaging of vasculature and ureter phantoms using MBIR results in similar noise and CNR compared to FBP at approximately one-sixth the dose. This suggests that, using MBIR, a one milliSievert exam of the ureters and vasculature may be clinically possible whilst still maintaining adequate image quality.

Establishing a Standard Protocol for the Voiding Cystourethrography

The voiding cystourethrogram (VCUG) is a frequently performed test to diagnose a variety of urologic conditions, such as vesicoureteral reflux. The test results determine whether continued observation or an interventional procedure is indicated. VCUGs are ordered by many specialists and primary care providers, including pediatricians, family practitioners, nephrologists, hospitalists, emergency department physicians, and urologists. Current protocols for performing and interpreting a VCUG are based on the International Reflux Study in 1985. However, more recent information provided by many national and international institutions suggests a need to refine those recommendations. The lead author of the 1985 study, R.L. Lebowitz, agreed to and participated in the current protocol. In addition, a recent survey directed to the chairpersons of pediatric radiology of 65 children's hospitals throughout the United States and Canada showed that VCUG protocols vary substantially. Recent guidelines from the American Academy of Pediatrics (AAP) recommend a VCUG for children between 2 and 24 months of age with urinary tract infections but did not specify how this test should be performed. To improve patient safety and to standardize the data obtained when a VCUG is performed, the AAP Section on Radiology and the AAP Section on Urology initiated the current VCUG protocol to create a consensus on how to perform this test.

[Imaging in urinary tract infections in childhood]

Diagnostic strategies for extended morphological and functional clarification after symptomatic urinary tract infections in children are changing. Improved knowledge of the causes for development of renal scarring and a changing view on the importance of vesicoureteral reflux have led to a change in paradigm in recent years. The purpose of this article is to present the ongoing discussions of the causes and outcome of childhood urinary tract infections, competing diagnostic imaging methods and different diagnostic algorithms.

Ectopic insertion of a duplicated ureter into prostatic urethra: Demonstration by 3D multi-detector computed tomography urography

Ectopic insertion of the ureter in the genitourinary tract is a rare congenital disorder, usually associated with ureteral duplication. Identification of the insertion open is critical for ureteric re-implantation. However, the challenge in the diagnosis of ectopic insertion of the ureter usually is to identify its insertion, particularly when the affected ureter is not dilated. Multi-detector computed tomography (MDCT) urography with nonionic iodinated contrast media delineates the ureteric course in the normal functioning kidney in the excretory phase [1]. This report presented a young male patient with ectopic insertion of a duplicated ureter diagnosed by MDCT urography. Three-dimensional (3D) analysis technology, such as volume rendering (with a color display improving the visualization of complex anatomy and 3D relationships) and maximum intensity projection (similar in principle to projection angiography), is useful for the illustration of urinary tract anatomy [1]. Rotated volume rendering reconstruction images and continual thinner maximum intensity projection reformatted images can be viewed as videos, which provides detail delineation of the ectopic ureteral insertion and its associated ureteral duplication.In this study, we reported MDCT urography and 3D analysis technology as an appropriate diagnostic method for the ectopic ureteral insertion and its associated complications.

Micturating cystourethrogram as a tool for investigating UTI in children - An institutional audit

BACKGROUND

Micturating cystourethrograms (MCUG) are the gold standard for evaluating vesicoureteric reflux (VUR). There is a growing consensus for increasing the threshold for performing MCUGs following urinary tract infections (UTI) in children. There are several varying guidelines. It is important to detect high-grade reflux in the setting of an UTI because of potential long-term complications.

OBJECTIVE

This audit aimed to retrospectively: (1) identify the conformance rate of local guidelines at the Women's and Children's Hospital (WCH); (2) assess predictors for an abnormal MCUG; and (3) compare local guidelines against the Royal Children's Hospital, Melbourne (RCH), National Institute for Healthcare and Excellence (NICE), and American Academy of Pediatrics (AAP) guidelines for selectively detecting high-grade reflux.

METHOD

The number of MCUGs performed from 2008 to 2012 at the WCH radiology department was collected. Patients undergoing MCUG during the 2012 calendar year were identified. Only children having an initial MCUG as part of an UTI investigation with prerequisite imaging as per guidelines were included. Each child's age, sex, referral source, reason, renal ultrasound (RUS) prior to the MCUG, MCUG result and VUR grade were recorded. The WCH guidelines were applied to determine conformance, to evaluate predictors for an abnormal MCUG, and compared against other retrospectively applied guidelines (RCH, NICE, AAP).

RESULTS/DISCUSSION

There was complete data for 168 children who underwent MCUG as part of an UTI investigation (median age 0.79 years, range 0.12-8.74, male:female 67:101). There were 67/168 abnormal MCUGs (62 children with VUR, five bladder diverticulum), and 97 refluxing renal units (43 high-grade VUR units). No posterior urethral valves (PUV) were identified as part of the UTI investigation. A total of 143/168 patients had prior RUS (normal:abnormal 67:76). The WCH guidelines had 82% conformance. There was no statistically significant association between an abnormal MCUG and age, sex, referral source, reason, or prior RUS result. The WCH guidelines may have missed five children with high-grade VUR (four children had surgery), compared with RCH, APP and NICE, with 8, 15, and 17 children, respectively, having high-grade VUR (two, five, and five children had surgery, respectively) show in the Summary Table. The retrospective study had limitations and possible selection bias (children with UTI without a MCUG). There were no standard treatment approaches for VUR; hence establishing a MCUG guideline is difficult. An alternative is the top-down approach.

CONCLUSION

Current institutional guidelines for considering MCUG following UTI in children vary considerably. The MCUG guidelines at any institution must take into account the local management guidelines for high-grade VUR.

Poor split renal function and age in adult patients with ureteropelvic junction obstruction do not impact functional outcomes of pyeloplasty

INTRODUCTION

To examine if poor preoperative split renal function (SRF) and age influence pyeloplasty outcomes in adults with ureteropelvic junction obstruction (UPJO).

MATERIALS AND METHODS

We retrospectively reviewed our pyeloplasty experience in adults with UPJO from 2004 to 2014. Patients with solitary kidneys or missing renal scans were excluded. Renal scans were performed at 6 weeks, 8 months, and 20-24 months postoperatively. Demographics, operative approaches, and pre and postoperative SRF and diuretic half-times (T1/2) were obtained. Patients were stratified by preoperative SRF (≤ or > 25%) and age. Cox regression analyses were performed to explore predictors for stability or improvement of SRF.

RESULTS

A total of 139 patients met the study criteria: 15 and 124 with preoperative SRF ≤ 25% and > 25%, respectively. Median follow up was 11 months, 12.9% of patients experienced worsening, 67.6% stability, and 19.4% improvement in SRF at last follow up. Median change in SRF was similar between groups; however, patients with lower preoperative SRF more frequently experienced improvement or worsening of SRF (p = 0.045). Failure rates (need for additional surgery) were comparable (p = 1.000). No significant differences were observed in SRF dynamicity when stratified by age (p = 0.120). On univariate Cox analysis, older age was predictive of stability or improvement in SRF across the entire cohort (HR 1.013, p = 0.016), while preoperative SRF was not (HR 1.007, p = 0.429).

CONCLUSIONS

Poor SRF (≤ 25%) and age were not associated with worse outcomes after pyeloplasty for UPJO. Our results suggest that older adults with UPJO and patients with poor ipsilateral SRF should not be excluded from pyeloplasty.

[How I TREAT... A RENAL COLIC]

Renal colic (RC) represents nearly 2% of emergency department admissions. RC is defined by the occurrence of back pain which may radiate towards the abdomen and external genitals. In adults, the obstruction is caused by a urinary stone in 80% of cases. The 20 % of non-stone related RCs are due either to an intrinsic obstruction (pyeloureteral junction stenosis, ureteral tumor, ...) or an extrinsic compression (pelvic tumor, lymphadenopathy ...). In over 90% of cases, an RC does not require hospitalization and is treated with medication. In contrast, complicated renal colic (CRC) requires hospitalization with specialized care. Obstructive pyelonephritis (OPN) is a form of CRC and the diagnosis should be considered in a clinical presentation of "renal colic" with acute pyelonephritis. This is a true emergency requiring surgical drainage of the upper urinary tract upstream of the obstacle, as well as antibiotic therapy. It must be kept in mind that some clinical presentations may be atypical, especially in the elderly, which can delay the diagnosis and, thus, the management. The gold standard for diagnosis is CT urography.

The Pediatric Urinary Tract and Medical Imaging

The pediatric urinary tract often is assessed with medical imaging. Consequently, it is essential for medical imaging professionals to have a fundamental understanding of pediatric anatomy, physiology, and common pathology of the urinary tract to provide optimal patient care. This article provides an overview of fetal development, pediatric urinary anatomy and physiology, and common diseases and conditions of the pediatric urinary tract.

Performance of simultaneous high temporal resolution quantitative perfusion imaging of bladder tumors and conventional multi-phase urography using a novel free-breathing continuously acquired radial compressed-sensing MRI sequence

PURPOSE

To investigate the feasibility of high temporal resolution quantitative perfusion imaging of bladder tumors performed simultaneously with conventional multi-phase MR urography (MRU) using a novel free-breathing continuously acquired radial MRI sequence with compressed-sensing reconstruction.

METHODS

22 patients with bladder lesions underwent MRU using GRASP (Golden-angle RAdial Sparse Parallel) acquisition. Multi-phase contrast-enhanced abdominopelvic GRASP was performed during free-breathing (1.4×1.4×3.0mm(3) voxel size; 3:44min acquisition). Two dynamic datasets were retrospectively reconstructed by combining different numbers of sequentially acquired spokes into each dynamic frame: 110 spokes per frame for 25-s temporal resolution (serving as conventional MRU for clinical interpretation) and 8 spokes per frame for 1.7-s resolution. Using 1.7-s resolution images, ROIs were placed within bladder lesions and normal bladder wall, a femoral artery arterial input function was generated, and the Generalized Kinetic Model was applied.

RESULTS

Biopsy/cystectomy demonstrated 16 bladder tumors (13 stage≥T2, 3 stage≤T1) and 6 benign lesions. All lesions were well visualized using 25-s clinical multi-phase images. Using 1.7-s resolution images, K(trans) was significantly higher in tumors (0.38±0.24) than normal bladder (0.12±0.02=8, p<0.001) or benign lesions (0.15±0.04, p=0.033). Ratio between K(trans) of lesions and normal bladder was nearly double for tumors than benign lesions (4.3±3.4 vs. 2.2±1.6), and K(trans) was nearly double in stage≥T2 than stage≤T1 tumors (0.44±0.24 vs. 0.24±0.24), although these did not approach significance (p=0.180-0.209), possibly related to small sample size.

CONCLUSION

GRASP allows simultaneous quantitative high temporal resolution perfusion of bladder lesions during clinical MRU examinations using only one contrast injection and without additional scan time.