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Triplication of ureter (TU) is a rare but important disease occurring in children. TU occurs with the early division of the ureteric bud or with three buds arising from mesonephric duct. It is commonly associated with other urological anomalies such as contralateral ureteric duplication, ureteral ectopia and renal dysplasia. Our case is a 3-year-old girl who presented with right triplex ureters and ureteropelvic junction (UPJ) obstruction of the upper pole. Diagnostic tools used in our case study were ultrasound (US), retrograde pyelography and CT urography for imaging. CT urography is a useful diagnostic tool for pediatric patients because it gives more information about anatomical details. J Med Cases. 2018;9(7):195-197 doi: https://doi.org/10.14740/jmc3060w

• There is great variation in the CT urogram protocol throughout the literature. • The study by Renard-Penna et al provides a useful rigorous expert consensus on CT urography technique. • The study by Rud et al suggests that the excretory phase may not be as necessary as previously thought for visualizing upper tract urothelial carcinoma.

Retrograde pyelography (RPG) is used in some centers to further evaluate patients with incompletely opacified segments on CT urography (CTU). This study intends to evaluate the utility of this imaging combination in terms of the yield of abnormal findings on the follow up RPG. In this retrospective study, we searched the radiology database over a three-year period (11/1/2015–10/30/2018) for patients who had a CTU and then a diagnostic RPG within 180 days. Images and reports were reviewed from this period for patients who met the inclusion criteria. 292 patients underwent a CTU with follow up RPG over the search period. 131/292 RPGs (44.9%) were performed because the CTU described at least one incompletely opacified ureteral segment. Of the 148 ureters evaluated in these 131 patients, 4 ureters (2.7%) showed an abnormality on follow up retrograde pyelogram—two revealed a stricture at the unfilled segment, and two revealed contour irregularity in the distal ureter (biopsy showed urothelial cell carcinoma in these two). There is a relatively low yield for detecting ureteral abnormalities when a retrograde pyelogram is performed after a CTU to evaluate an incompletely opacified ureteral segment—2.7% in our study, with only two of these incompletely opacified segments containing urothelial cancer (1.4%). In these two cases, a ureteral abnormality was visible on the CTU and RPG would seem to have a very low yield for follow up of unopacified ureteral segments if the ureters are otherwise normal-appearing on CTU and there is no hydronephrosis.

Fraley's syndrome is a rare cause of obstruction of the collecting system. It results from an extrinsic vascular compression of a calyceal infundibulum by a branch of the renal artery. Clinicians should be aware of this syndrome when facing an isolated dilatation of a calyx, classically an upper pole calyx dilatation, with a defect in the superior infundibulum on CT urography. Here, we pictorially present the conservative surgical treatment of a Fraley's syndrome. After identification of the artery responsible for the obstruction, the infundibulum was opened, uncrossed from the vessel, and closed by an end-to-end anastomosis.

PURPOSE: To summarize knowledge on upper urinary tract carcinoma (UTUC) regarding diagnostic procedures, risk factors and prognostic markers.METHODS: A scoping review approach was applied to search literature in Pubmed, Web of Science, and Embase. Consensus was reached through discussions at Consultation on UTUC in Stockholm, September 2018.RESULTS: Tumor stage and grade are the most important prognostic factors. CT urography (CTU) including corticomedullary phase is the preferred imaging modality. A clear tumor on CTU in combination with high-grade UTUC in urine cytology identifies high-risk UTUC, and in some cases indirect staging can be obtained. Bladder urine cytology has limited sensitivity, and in most cases ureterorenoscopy (URS) with in situ samples for cytology and histopathology are mandatory for exact diagnosis. Image-enhancing techniques, Image S1 and narrow-band imaging, may improve tumor detection at URS. Direct confocal laser endomicroscopy may help to define grade during URS. There is strong correlation between stage and grade, accordingly correct grading is crucial. The correlation is more pronounced using the 1999 WHO than the 2004 classification: however, the 1999 system risks greater interobserver variability. Using both systems is advisable. A number of tissue-based molecular markers have been studied. None has proven ready for use in clinical practice.CONCLUSIONS: Correct grading and staging of UTUC are mandatory for adequate treatment decisions. Optimal diagnostic workup should include CTU with corticomedullary phase, URS with in situ cytology and biopsies. Both WHO classification systems (1999 and 2004) should be used to decrease risk of undergrading or overtreatment.

Objectives: To compare the image quality of low-dose CT urography (LD-CTU) using deep learning image reconstruction (DLIR) with conventional CTU (C-CTU) using adaptive statistical iterative reconstruction (ASIR-V). Methods: This was a prospective, single-institutional study using the excretory phase CTU images for analysis. Patients were assigned to the LD-DLIR group (100kV and automatic mA modulation for noise index (NI) of 23) and C-ASIR-V group (100kV and NI of 10) according to the scan protocols in the excretory phase. Two radiologists independently assessed the overall image quality, artifacts, noise and sharpness of urinary tracts. Additionally, the mean CT attenuation, signal-to-noise ratio (SNR) and contrast-to-noise (CNR) in the urinary tracts were evaluated. Results: 26 patients each were included in the LD-DLIR group (10 males and 16 females; mean age: 57.23 years, range: 33–76 years) and C-ASIR-V group (14 males and 12 females; mean age: 60 years, range: 33–77 years). LD-DLIR group used a significantly lower effective radiation dose compared with the C-ASIR-V group (2.01 ± 0.44 mSv vs 6.9 ± 1.46 mSv, p < 0.001). LD-DLIR group showed good overall image quality with average score >4 and was similar to that of the C-ASIR-V group. Both groups had adequate and similar attenuation value, SNR and CNR in most segments of urinary tracts. Conclusion: It is feasibility to provide comparable image quality while reducing 71% radiation dose in low-dose CTU with a deep learning image reconstruction algorithm compared to the conventional CTU with ASIR-V. Advances in knowledge: (1) CT urography with deep learning reconstruction algorithm can reduce the radiation dose by 71% while still maintaining image quality.

L’uretere retrocave est une malformation rare. Par ces 3 cas, les auteurs rappellent que cette affection est retrouvee plus souvent chez l’adulte jeune. La manifestation clinique habituelle etant la douleur lombaire due a l’obstruction du haut appareil urinaire, les formes asymptomatiques aussi peuvent etre rencontrees. Le diagnostic reposant sur l’uroscanner son traitement au Togo et dans la plupart des pays africains demeure la chirurgie ouverte qui donne autant de bons resultats que la laparoscopie. Mots cles: Uretere retrocave; diagnostic; traitement; Africa English Title: Management of the retrocaval ureter in Togo about 3 cases English Abstract Retrocaval ureter is a rare malformation. By these 3 cases, the authors point out that this disease is found most often in young adults. Although the usual clinical presentation is the lumbar pain due to the obstruction of the upper urinary tract, asymptomatic forms are also found. The diagnosis is based on CT urography and the treatment in Togo and most African countries remains open surgery with good results as laparoscopy. Keywords: Retrocaval ureter; diagnosis; treatment; africa

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 scanner. 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

Dual-energy CT is being increasingly used for abdominal imaging due to its incremental benefit of material characterization without significant increase in radiation dose. Knowledge of the different dual-energy CT acquisition techniques and image processing algorithms is essential to optimize imaging protocols and understand potential limitations while using dual-energy CT renal imaging such as urinary calculi characterization, assessment of renal masses and in CT urography. This review article provides an overview of the current dual-energy CT techniques and use of dual-energy CT in renal imaging.

To retrospectively evaluate the diagnostic performance of single-phase dual-energy CT (DECT) with virtual non-contrast CT (VNCT) compared with three-phase CT urography (CTU) in patients with haematuria. A total of 296 patients underwent three-phase CTU (NCT at 120 kVp; nephrographic phase and excretory phase DECTs at 140 kVp and 80 kVp) owing to haematuria. Diagnostic performances of CT scans were compared for detecting urothelial tumours and urinary stones. Dose-length product (DLP) was compared in relation to single-phase DECT and three-phase CTU Dose-length product (DLP) was compared in relation to single-phase DECT and three-phase CTU. Sensitivity and specificity for tumour were 95 % (19/20) and 98.9 % (273/276) on CTU, 95 % (19/20) and 98.2 % (271/276) on nephrographic phase DECT, and 90 % (18/20) and 98.2 % (271/276) on excretory phase DECT (P > 0.1). Of the 148 stones detected on NCT, 108 (73 %) and 100 (67.6 %) were detected on nephrographic phase and excretory phase VNCTs, respectively. The mean size of stones undetected on nephrographic and excretory VNCTs was measured as 1.5 ± 0.5 mm and 1.6 ± 0.6 mm, respectively. The mean DLPs of three-phase CTU, nephrographic phase DECT and excretory phase DECT were 1076 ± 248 mGy · cm, 410 ± 98 mGy · cm, and 360 ± 87 mGy · cm, respectively (P

We report a case of eosinophilic cystitis in a 7-year-old boy with a history of atopic symptoms, with focus on the radiological findings. He presented with hematuria and dysuria and ultrasonography (US) showed irregular bladder wall thickening resembling a bladder mass. CT urography did not characterize the lesion any further and showed no local or distant spread. Biopsies revealed eosinophilic cystitis, a benign inflammatory condition. We found that US characterized the lesion at least as well as CT and should be the first choice of imaging. When staging is considered before biopsy, MRI should be preferred to CT. There are no specific radiological signs of eosinophilic cystitis. On follow-up, US was a safe, cost-effective imaging modality, but findings should be interpreted in a clinical context. In a child with hematuria and a bladder mass, eosinophilic cystitis is a relevant but rare differential diagnosis, especially when there is a known atopic history.

To evaluate the image quality of CT urography (CTU) obtained with ultra-high-resolution CT (U-HRCT) reconstructed with hybrid iterative reconstruction (IR) and model-based IR algorithms.Forty-eight patients who underwent CTU using the U-HRCT system were enrolled in this retrospective study. Excretory phase images were reconstructed with three protocols: Protocol A: 1024-matrix, 0.25 mm-thickness, and model-based IR; Protocol B: 1024-matrix, 0.25 mm-thickness, and hybrid IR; Protocol C: 512-matrix, 0.5 mm-thickness, and model-based IR. Objective image noise and contrast-to-noise ratio (CNR) of the renal pelvis were compared among the protocols. Three-dimensional maximum intensity projection CTU images were generated from each image data set, and image quality was evaluated by two radiologists.Protocol C yielded the lowest objective image noise and highest CNR, whereas Protocol A had highest image noise and lowest CNR (P 0.01). Regarding the detailed delineation of urinary tract structures on the images, the mean visual score was significantly higher for Protocol A than for Protocols B and C (P 0.001), and the mean score for subjective image noise was significantly lower for Protocol A than for Protocols B and C (P 0.001).CTU with a 1024-matrix and model-based IR depicted the structures of the urinary system in the most detail.

Purpose Patients with hematuria and renal colic often undergo CT scanning. The purpose of our study was to assess variations in CT protocols and radiation doses for evaluation of hematuria and urinary stones in 20 countries. Method The International Atomic Energy Agency (IAEA) surveyed practices in 51 hospitals from 20 countries in the European region according to the IAEA Technical cooperation classification and obtained following information for three CT protocols (urography, urinary stones, and routine abdomen-pelvis CT) for 1276 patients: patient information (weight, clinical indication), scanner information (scan vendor, scanner name, number of detector rows), scan parameters (such as number of phases, scan start and end locations, mA, kV), and radiation dose descriptors (CTDIvol, DLP). Two radiologists assessed the appropriateness of clinical indications and number of scan phases using the ESR Referral Guidelines and ACR Appropriateness Criteria. Descriptive statistics and Student’s t tests were performed. Results Most institutions use 3-6 phase CT urography protocols (80%, median DLP 1793-3618 mGy.cm) which were associated with 2.4-4.9-fold higher dose compared to 2-phase protocol (20%, 740 mGy.cm) (p < 0.0001). Likewise, 52% patients underwent 3-5 phase routine abdomen- pelvis CT (1574-2945 mGy.cm) as opposed to 37% scanned with a single-phase routine CT (676 mGy.cm). The median DLP for urinary stones CT (516 mGy.cm) were significantly lower than the median DLP for the other two CT protocols (p < 0.0001). Conclusions Few institutions (4/13) use low dose CT for urinary stones. There are substantial variations in CT urography and routine abdomen- pelvis CT protocols result in massive radiation doses (up to 2945-3618 mGy.cm).

The purpose of this study was to compare dual-energy CT (DECT) urography with a 50% reduced iodine dose to single-energy CT (SECT) urography with a standard iodine dose with respect to attenuation of renal vascular and urinary tract structures and with respect to image quality.The study included 62 patients undergoing evaluation of urinary tract lithiasis, tumor, or hematuria. Thirty-one patients underwent DECT urography with a 50% reduced iodine dose and reconstruction at 50 and 77 keV. These subjects were sex, age, and size matched to a group of 31 patients who underwent 120-kVp SECT urography with a standard iodine dose. The mean iodine dose was 22 g for DECT and 44 g for SECT. Attenuation was measured at seven locations in the renal arteries, renal veins, and urinary tract. Two reviewers subjectively scored the image quality parameters image noise, sharpness of urinary tract contours, enhancement of urinary structures, and streak artifacts.Mean DECT attenuation at 50 keV was the same as or greater than SECT attenuation at each of the seven locations. Measured image noise was highest at 50-keV DECT but was the same for 77-keV DECT and 120-kVp SECT. Mean subjective scores for DECT image quality parameters were the same as or higher than those of SECT, except for streak artifact and sharpness of urinary tract contours.DECT urography with a 50% reduced iodine dose may result in measured renal vascular and urinary tract attenuation the same as or higher than and image quality measurements and scores similar to those obtained with 120-kVp SECT urography with a standard iodine dose.

The purpose of this study is to prospectively compare the image quality of and confidence in the presence of a lesion on CT urography images acquired using filtered back projection (FBP) with 100% and 50% radiation doses with those for images simultaneously acquired using sinogram-affirmed iterative reconstruction with strength 3 (SAFIRE) with 50% and 25% radiation doses for patients with a high risk for urothelial carcinomas.A total of 150 patients randomly underwent CT urography examinations performed using a dual-source single-energy scanner. After the radiation output of each tube was adjusted, datasets at three radiation dose levels were reconstructed using FBP and SAFIRE. Seven radiologists subjectively assessed image quality and confidence in the presence of a lesion for a total of 1200 datasets. Nonparametric methods for cluster data were used to estimate AUC values for variance methods on the basis of a noninferiority margin of 0.05.The mean AUC value for image quality in SAFIRE with a 25% radiation dose was significantly lower than that of FBP with 100% radiation dose (p0.05 for all). The mean AUC values for the presence of a lesion were 0.907 and 0.894 for FBP, respectively, at 100% and 50% radiation doses, respectively, and 0.900 and 0.799 for SAFIRE at 50% and 25% radiation doses, respectively. However, the image quality of images acquired with SAFIRE at a 25% radiation dose was significantly inferior to that of images acquired with FBP at a 100% radiation dose.Regardless of the experience of the radiologist, CT urography images acquired with FBP and SAFIRE with a 50% radiation dose were noninferior to those acquired with FBP with a 100% radiation dose in terms of image quality and confidence in the presence of a lesion, whereas those acquired with SAFIRE with 25% radiation dose were inferior.

We performed a systematic review of the literature regarding the diagnosis and treatment of caliceal diverticulum (CD).The search strategy was conducted according to the Cochrane review guidelines for systematic reviews and Preferred Reporting Items for Systematic reviews and Meta-Analyses checklist.In total 1189 titles and abstracts were reviewed, of which 101 were selected for article evaluation. Of these 101 articles, 40 were selected for inclusion after full article evaluations. In the extracted article, intravenous urography (IVU), rather than CT urography, was the main imaging tool for diagnosis, although many articles had failed to provide any imaging modality information. The extracted articles included 88, 153, and 487 patients who underwent shock wave lithotripsy (SWL), flexible ureteroscopy/retrograde intrarenal surgery (fURS/RIRS), and percutaneous nephrolithotomy (PCNL), respectively. Stone-free rates were 21.3% (SWL), 61.4% (fURS/RIRS), and 83.0% (PCNL). The complication rates were 8.0% (SWL), 3.3% (fURS/RIRS), and 11.9% (PCNL). There was incomplete and inconsistent reporting of even basic clinical parameters, such as the size and location of the CD, number of stones, outcomes, and complications. There was a striking lack of follow-up data, despite a known high recurrence rate. The literature on laparoscopic management was too sparse to analyze.This meta-analysis revealed that there are not enough high-quality studies to evaluate the ideal strategy for the diagnosis and treatment of CDs. This systematic review emphasizes (a) the importance of contrast imaging for CD diagnosis, (b) higher success rates but also higher complication rates in PCNL compared with SWL and FURS, and (c) the need for standardized reporting of outcomes to include complications, number of interventions, symptom resolution, stone clearance, and CD ablation.

A 33-year-old non-diabetic married woman from rural background presented with complaints of dull intermittent right flank pain since 1 year. She had no history of fever, dysuria, haematuria or weight loss. Clinical examination of the abdomen was within normal limits. Complete laboratory evaluation including urinalysis, complete blood picture, urea, creatinine and electrolytes were within normal limits. Ultrasonography (USG) of kidney, ureters and bladder showed moderate hydroureteronephrosis (HDUN) until right midureter. Intravenous pyelography (IVP) revealed dilated right renal pelvicalyceal system and upper ureter with abrupt S-shaped turn of ureter at the level of L4 vertebrae. The appearance on IVP was strongly suspicious of retrocaval ureter and hence a contrast-enhanced CT urography was performed to confirm the diagnosis, which showed dilated right proximal ureter (figure 1) coursing medially and lying posterior …

Elderly patients with upper tract urothelial cancer (UTUC) may present with colic and microscopic haematuria, mimicking urolithiasis. Patients presenting to emergency departments with acute ureteric colic are investigated with a CT KUB. CT urography (CTU) identifies UTUC better than a CT KUB. Thus, there is a possibility that a CT KUB may miss UTUC. We studied patients aged 65 years or over presenting to the emergency department with ureteric colic and microscopic haematuria who had a CT KUB between January 2014 and October 2016. Patients who had both CT KUB and CTU were then compared to determine if CT KUB had missed a UTUC and if the diagnoses were concordant by the two tests. A radiologist independent from the reporting radiologists reviewed images as well as their reports. According to the Health Research Authority, England regulations, we did not obtain an ethical review on a voluntary basis for this retrospective study. Four hundred eighty-five patients [228 (47.01%) male and 257 (52.99%) female] had a CT KUB scan over the 34-month period. Their mean age was 74 (SD 6.97) [males 73 (SD 6.42), females 75 (SD 7.42)] years. One hundred eighty-seven scans were normal. Ureteric calculi (167), renal calculi (58) and renal cysts (28) were most frequent diagnoses. The diagnosis was uncertain in 33 patients (6.8%) [16 (48.49%) males and 17 (51.51%) females]. The mean age of this group of patients was 74 (SD 6.64) [males 73 (SD4.43), females 74 (SD7.64)] years. These patients had a CTU for clarity. CTU identified one UTUC not identified by CT KUB (0.2%), corroborated the diagnosis of a ureteric tumour in one patient and excluded UTUC in two others. CTU diagnosed two new bladder tumours and an endometrial tumour. Diagnoses were concordant between CT KUB and CTU in 17 of 33 patients (51.5%). CT KUB scans for patients 65 years and over presenting with ureteric colic is justified. Only a small proportion of patients will subsequently require the higher radiation dose CTU as the probability of missing UTUC is low.

Objectives To evaluate the usefulness of adding diffusion-weighted MRI (DW-MRI) to CT urography (CTU) for diagnosing upper tract urothelial carcinoma (UTUC). Materials and methods We retrospectively evaluated 102 high-risk patients with UTUC who underwent both CTU and DW-MRI. The diagnostic performance of CTU and DW-MRI was evaluated in all the patients. Then, the diagnostic performance of DW-MRI in the patients with positive CTU findings was assessed based on the types of CTU findings (mass formation, wall thickening, and small filling defects). The diagnostic performance of DW-MRI and selective urine cytology sampling in these patients was also compared. Results The sensitivity of DW-MRI (92%) was less than that of CTU (98%) (P = 0.25), since DW-MRI could not detect any small papillary tumors. The specificity of DW-MRI (91%) was greater than that of CTU (78%) (P = 0.065), since DW-MRI could discriminate some benign conditions from UTUC. Among the 59 positive CTU lesions, DW-MRI correctly diagnosed all 41 mass-forming lesions and improved the accuracy from 36% using CTU alone to 79% for 14 wall-thickening lesions but could not add any additional information for 4 small filling-defect lesions. Among the 44 patients with positive CTU findings who underwent selective urine cytology sampling, the sensitivity of DW-MRI (95%) was significantly greater than that of selective urine cytology sampling (56%) (P Conclusions The addition of DW-MRI would be useful for both mass-forming and wall-thickening lesions. DW-MRI has the potential to reduce the frequency of selective urine cytology sampling for such lesions.

We are developing a computer-aided detection system for bladder cancer in CT urography (CTU). Bladder wall thickening is a manifestation of bladder cancer and its detection is more challenging than the detection of bladder masses. We first segmented the inner and outer bladder walls using our method that combined deep-learning convolutional neural network with level sets. The non-contrast-enhanced region was separated from the contrast-enhanced region with a maximum-intensity-projection-based method. The non-contrast region was smoothed and gray level threshold was applied to the contrast and non-contrast regions separately to extract the bladder wall and potential lesions. The bladder wall was transformed into a straightened thickness profile, which was analyzed to identify regions of wall thickening candidates. Volume-based features of the wall thickening candidates were analyzed with linear discriminant analysis (LDA) to differentiate bladder wall thickenings from false positives. A data set of 112 patients, 87 with wall thickening and 25 with normal bladders, was collected retrospectively with IRB approval, and split into independent training and test sets. Of the 57 training cases, 44 had bladder wall thickening and 13 were normal. Of the 55 test cases, 43 had wall thickening and 12 were normal. The LDA classifier was trained with the training set and evaluated with the test set. FROC analysis showed that the system achieved sensitivities of 93.2% and 88.4% for the training and test sets, respectively, at 0.5 FPs/case.

For non-muscle invasive bladder cancer (Ta, T1 and CIS) ultrasonography (US) is the first method used to investigate the anatomy of the bladder and the upper urinary tract. Intravenous urography has been used for decades and today CT urography is being used with increased frequency. CT urography is the gold standard for exploration of the upper urinary tract with reported sensitivity and specificity of 93.5 and 94.8 % for the detection of urothelial cancer.

Pancake kidney is a very rare congenital anomaly involving complete fusion of medial renal parenchyma. The interface is devoid of any intervening septum. As described, the kidneys form a single lobulated mass in pelvic location. However, dual collecting systems are retained, and the shortened, anteriorly seated ureters enter the bladder normally. This condition is usually discovered incidentally but may confer a heightened susceptibility to recurrent urinary tract infections or stone formation, given the likelihood of anomalous collecting system rotation and the potential for ureteral stasis or obstruction. Excretory urography, the customary method of detection, has been replaced by ultrasonography, CT, MRI, and radionucleotide scanning. Herein, we present a male patient with a pelvic pancake kidney, never symptomatic. A conservative approach of regular follow up visits and laboratory testing was elected, thus avoiding any unnecessary investigations or extensive surgery.

The objective of our study was to compare the diagnostic performance of nephrographic phase only, excretory phase only, and both nephrographic and excretory phases of CT urography (CTU) for the detection of upper tract urothelial carcinoma.Forty-nine consecutive patients with pathologically proven upper tract urothelial carcinoma who underwent a single-bolus CTU examination were evaluated. Forty-nine control patients with normal findings on two CTU examinations performed at a 1-year interval were included. Two radiologists independently reviewed the 98 CTU examinations at three different sessions (nephrographic phase only, excretory phase only, and both nephrographic and excretory phases simultaneously) and rated the likelihood of the presence of a urothelial carcinoma in each segment of the renal collecting system and ureter using a 5-point scale. Sensitivity, specificity, and AUC of ROC curve were calculated per segment and per patient.A total of 314 segments, 56 of which contained tumors, were evaluated. In the per-segment analysis for reviewers 1 and 2, the sensitivity, specificity, and AUC, respectively, were as follows: 88%, 98%, and 0.95 and 84%, 97%, and 0.94 for the nephrographic phase; 79%, 98%, and 0.91 and 89%, 98%, and 0.95 for the excretory phase; and 88%, 99%, and 0.95 and 89%, 99%, and 0.96 for the combined nephrographic and excretory phases. The AUC of the combined nephrographic and excretory phases was significantly higher than that of the nephrographic phase (per-patient analysis, reviewer 2) and that of excretory phase (per-segment analysis, reviewer 1) but was not significantly different in any other comparisons.The nephrographic and excretory phases are complementary for the detection of upper tract urothelial carcinoma.

The purpose of this study was to survey the radiation dose used in CT urography (CTU) in routine clinical practice, both before and after implementation of a scanning protocol that uses iterative reconstruction (Adaptive Iterative Dose Reduction 3D [AIDR 3D]).We retrospectively surveyed dose reports from consecutive CTU examinations performed in 2011 with the use of 64- and 320-MDCT scanners that were reconstructed with filtered back projection (FBP) and from CTU examinations performed from May 2012 through November 2013 that were reconstructed with the use of AIDR 3D. Findings from these dose reports were then correlated with such patient characteristics as weight and body mass index (BMI; weight in kilograms divided by the square of height in meters). Only dose reports from single-bolus three-phase CTU examinations were included in the study. The volume CT dose index, dose-length product (DLP), and effective dose were surveyed both per examination and per phase by use of published effective dose DLP conversion factors. Image quality was evaluated subjectively for a subset of patients.The two study cohorts included 82 patients (median patient weight, 75.0 kg; median BMI, 25.3) who underwent CTU with FBP and 85 patients (median patient weight, 78.0 kg; median BMI, 24.5) who underwent CTU with AIDR 3D. The median total DLP and median effective dose were 924 mGy · cm and 13.0 mSv, respectively, in the CTU with the FBP cohort and 433 mGy · cm and 6.1 mSv, respectively, in the CTU with the AIDR 3D cohort. The median DLP in the unenhanced, nephrogenic, and excretory phases was 218, 300, and 441 mGy · cm, respectively, in patients undergoing CTU with FBP and 114, 121, and 190 mGy · cm, respectively, in patients undergoing CTU with AIDR 3D. Image quality was diagnostic in both groups, with relatively fewer artifacts noted on scans obtained using CTU with AIDR 3D.Our study presents detailed dose data from three-phase CTU examinations performed both before and after implementation of iterative reconstruction. Implementation of a CTU protocol using iterative reconstruction resulted in a mean effective dose of 6.1 mSv with preservation of clinical diagnostic image quality.

Background Computed tomography (CT) urography is now used in the work-up of patients with hematuria. The dose of contrast medium and radiation varies considerably between the different CT protocols. Purpose To study the disease prevalence in a consecutive group of patients with hematuria undergoing CT urography with a low dose of contrast medium and radiation. Material and Methods From 1 April 2007 to 31 March 2008, using the Radiological Information System (RIS) as well as electronic patient records, demographic data, reason for referral, and diagnosis were obtained for all patients undergoing CT urography due to hematuria. The patients were followed for 3 years. Results A total of 771 patients had hematuria diagnosed at the time of referral. In 137 patients (18%), a tumor and / or a complex cyst was found in the urinary tract (renal, ureteral, or bladder), in 68 (9%) a calculi, in 118 (15%) other disease (i.e. infection or anomaly) was found. No abnormalities were found at CT urography in 455 (58%) of the patients with hematuria. Lesions were found more frequently in patients with visible hematuria than in patients with non-visible hematuria (48% vs. 29%). No malignant tumor or complex cyst was found in the kidneys or the ureters in patients with nonvisible hematuria. Conclusion CT urography with its low dose of contrast medium and radiation is a useful diagnostic imaging test for investigating patients with hematuria.

Introduction: Computed tomographic urography (CTU) is gaining popularity as the first line investigation for haematuria. It can be used to produce a ‘true’ one-stop clinical assessment. However, a large number of investigations can be negative, exposing patients to a number of risks. Objective: We set out to evaluate the use of CTU in our one-stop haematuria clinic to see if it supported the utilisation of CTU as a triage investigation for haematuria. Methods: Retrospective analysis of all CT urograms performed (508) in our trust in 2013 took place. CTUs requested from the haematuria clinic were identified and analysed further. Results: A total of 1086 patients attended the haematuria clinic in 2013. 168 males and 78 females (median age 64, range 25 to 90) went on to have further CTU investigation after ultrasonography (USS) and cystoscopy. Visible haematuria (VH) was reported in 95% of cases. All 9 confirmed cases of upper tract urothelial carcinoma lesions presented with VH (age > 50); 8 out of 9 had reported hydronephrosis on USS. The overall negative predictive CTU rate was 96%. Conclusion: Our results show that a large number of CTUs are negative. The use of risk stratification, with particular emphasis on the ultrasonography result, gives adequate guidance on the cases that require further CTU investigation, supportive of the current European Association of Urology guidelines. Our results do not support the use of CTU as a first line or triage investigation for haematuria.

The safety and efficacy of multi-planar reconstruction (MPR) image post-processing technique-computed tomography (CT) urography (CTU) combined with precise intraoperative ultrasonography guided flexible ureteroscope in renal cyst incision and drainage in the treatment of cystic diseases of kidney were evaluated. A total of 68 patients were randomly divided into control and observation group (n=34). All the patients were treated with renal cyst incision and drainage under flexible ureteroscope. The control group was under ultrasound guidance. The observation group was combined with MPR-CTU, the safety and efficacy was compared. There was no significant difference between the two groups in the success rate and the time of cyst treatment (P>0.05). The incidence of intraoperative and postoperative complications of the observation group was significantly lower than that of the control group. After 1 month follow-up, the total effective rate of the observation group was significantly higher than that of the control group, the difference was statistically significant (P

While urothelial carcinoma is a very common tumor, involvement of the upper tract is relatively uncommon. Consequently, there are no consensus imaging recommendations for upper tract disease. CT urography is the dominant imaging modality for the upper tract, but despite its excellent performance characteristics and being widely accepted as standard of care there is great variability in how CTU exams are performed across practices. MR urography has limited current application, but has the potential to become more mainstream in the future with continued technical advances. Upper tract urothelial carcinoma can manifest as a variety of appearances: a papillary lesion, focal wall thickening, focal enhancement, or as an infiltrative lesion. Pelvicalyceal location is about twice as common as in the ureter. Tumors in the pelvicalyceal location often manifest as an irregular enhancing soft tissue attenuation filling defect, and may be sessile or polypoid in morphology. Within the ureter, 73% are located in the distal segment.

Objective: To evaluate the correlation between CT urography (CTU) findings and histological grade of ureteral urothelial carcinoma (UUC), and to identify predictors of high-grade UUC. Methods: CTU images of 73 patients with pathologically proven UUC via nephroureterectomy were independently reviewed by two radiologists for tumour size, tumour location, hydronephrosis grade, periureteral infiltration, presence of enlarged retroperitoneal lymph nodes and tumour enhancement value. Interobserver agreement was assessed with kappa statistics. Histological grade was classified as either low or high according to the WHO 2004 classification system and pathologic T stage was assessed according to the TNM staging system. Binary logistic regression, Spearman correlation analysis and receiver operating characteristic curves were used to evaluate relationships between CTU findings and histological grade. Results: 58 patients had high-grade UUCs and 15 had low-grade UUCs. Among CTU features, only hydronephrosis grade was significantly correlated with high tumour grade for both readers (p < 0.001). Multivariate logistic regression revealed that hydronephrosis of Grade 3 or higher was a significantly independent predictor of high-grade UUC for both readers (p ≤ 0.004). Interobserver agreement was excellent for hydronephrosis grade (к = 0.862). With the cut-off value of hydronephrosis Grade 3, the sensitivity, specificity and area under the curve for predicting high-grade UUC were, respectively, 88%, 79% and 0.830 for reader 1 and 86%, 80% and 0.763 for reader 2. Conclusion: Hydronephrosis of Grade 3 or higher on CTU may be predictive of high-grade UUC. Advances in knowledge: Radical surgery should be considered for UUC causing hydronephrosis of Grade 3 or higher on CTU, even in small tumours without periureteral infiltration.

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. 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. 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. 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.

OBJECTIVE. Dual-energy CT (DECT) is being increasingly used for abdominal imaging because it provides incremental benefit of material characterization without significant increase in radiation dose. This article provides an overview of current DECT techniques and use of DECT in urinary tract imaging for assessment of renal masses and urinary calculi characterization and in CT urography. CONCLUSION. Incorporation of DECT into clinical practice and use of its material characterization capabilities in urinary tract imaging enable characterization of urinary calculi and incidental renal lesions and can reduce radiation dose by allowing generation of virtual unenhanced images.

To assess the diagnostic yield of a computed tomography urography (CTU) study in patients less than 50 years of age, who have a history of military service, and who are at increased risk of urological cancers secondary to harmful practices and work-related exposures. 137 Consecutive patients who underwent CTU between 2012 and 2013 for new onset of hematuria were included. Initial review of the clinical interpretations of the CTU studies grouped the studies into negative and positive exams for any urological findings. Review of the patients’ medical records and subsequent radiology studies determined microscopic versus gross hematuria at presentation and any findings after their CTU study consistent with a urological malignancy. The positive exams were reviewed by second readers, blinded to the clinical interpretation of the initial CTU studies, who first read the unenhanced images. The readers characterized findings as visible on non-contrast CT alone or they requested contrast-enhanced images. Each urological finding was recorded for each patient. Of the 137 included patients, 84 had micro-hematuria and 53 had gross hematuria. There were a total of 99 negative examinations of the 137 included patients. Contrast was requested 14 times to confirm 11 benign cysts. No findings concerning for malignancy were found by the readers or on subsequent record reviews for each patient. An unenhanced CT may be appropriate to evaluate new onset microscopic, and possibly gross hematuria, in patients younger than 40, even in patients at increased risk of urologic cancer.

ObjectiveTo investigate diagnostic accuracy of multiphase computed tomography urography (MCTU) and visual assessment at ureterorenoscopy (URS) for detection of upper tract urothelial carcinoma (UTUC).Patients and MethodsConsecutive patients referred to our tertiary care centre were included in a prospective study covering the period 2005 to 2012. The patients underwent initial imaging and URS with focal samples taken. Cytopathological results served as reference standard.ResultsWe investigated 174 renal units (RUs; renal pelvis and adjacent ureter) in 148 patients. UTUC was found in 104 RUs. MCTU had an accuracy of 0.74, sensitivity of 0.89, specificity of 0.51, positive predictive value of 0.73, and negative predictive value of 0.75; corresponding values for URS were 0.84, 0.84, 0.85, 0.89, and 0.78, respectively. MCTU had significantly higher sensitivity and accuracy compared with other imaging techniques (PConclusionBoth MCTU and URS are important tools in the diagnostic evaluation of UTUC although neither of those techniques achieves 100% accuracy. MCTU should be chosen as the radiographical method if there are no contraindications and URS should always be combined with focal cytology and biopsies of suspicious lesions. To enhance diagnostic precision both MCTU and URS with focal samples should be included in the diagnostic procedure. The present results add impact to current diagnostic guidelines.

The diffusion of MDCT in veterinary practice has changed approaches to many urinary tract disorders, such as urolithiasis, renal masses, and mucosal abnormalities of the renal collecting system, ureters, and bladder. As MDCT has become more widely available, CT urography has begun to replace other imaging techniques, such as plain-film radiography and excretory urography, because it enables accurate depiction of the renal collecting systems through thinner-section imaging, more rapid scanning, improved longitudinal spatial resolution, and the consequent acquisition of high-quality reformatted multiplanar and 3D images. Moreover, qualitative and quantitative assessment of renal and excretory function is possible using dynamic CT and most advanced perfusion imaging techniques. One of the clinical applications of dual-energy (DE) CT is the spectral analysis of urinary calculi.

Intravenous urography (IVU) and CT urography (CTU) are efficient radiological examinations for the evaluation of the urinary system disorders. However patients are exposed to a significant radiation dose. The objectives of this study are to: (i) measure and compare patient radiation dose by computed tomography urography (CTU) and conventional intravenous urography (IVU) and (ii) evaluate organ equivalent dose and cancer risks from CTU and IVU imaging procedures. A total of 141 patients were investigated. A calibrated CT machine (Siemens-Somatom Emotion duo) was used for CTU, while a Shimadzu X ray machine was used for IVU. Thermoluminescence dosimeters (TLD-GR200A) were used to measure patients' entrance surface doses (ESD). TLDs were calibrated under reproducible reference conditions. Patients radiation dose values (DLP) for CTU were 172±61 mGy cm, CTDI vol 4.75±2 mGy and effective dose 2.58±1 mSv. Patient cancer probabilities were estimated to be 1.4 per million per CTU examination. Patients ESDs values for IVU were 21.62±5 mGy, effective dose 1.79±1 mSv. CT involves a higher effective dose than IVU. In this study the radiation dose is considered low compared to previous studies. The effective dose from CTU procedures was 30% higher compared to IVU procedures. Wide dose variation between patient doses suggests that optimization is not fulfilled yet.