Reliability assessment of the upper urinary tract dilation grading system based on magnetic resonance urography in patients with neurogenic bladder.

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

Air vs contrast pyelogram for initial puncture access in percutaneous nephrolithotomy: a randomized controlled trial.

Percutaneous nephrolithotomy (PCNL) is a standard procedure for large renal stones. Contrast (traditionally) as well as air is being used to delineate pelvi-calyceal system (PCS) to perform initial puncture. Contrast, when used has certain disadvantages including poor differentiation of anterior and posterior calyces. In this interim analysis of 122 patients of a prospective study subjects were stratified in two groups: in group 1, contrast was used while in group 2, air was used to delineate PCS. Out of 122,103 patients underwent puncture by contrast or air exclusively while 19 patients required mix of contrast and air (14 patients failed puncture using contrast while 5 using air). Mean dosage of radiation exposure (8.43 vs. 14.26 mGy), duration of radiation exposure (0.66 vs. 1.02 min), access time (3.72 vs. 5.84 min), were less in group 2 as compared to group 1. 84.5% of patients underwent puncture in single attempt in group 2 as compared to 56.25% in group 1. Five patients had post-operative fever and one had trans-pleural tract dilation. Complete stone clearance was seen in 94.8% of patients using air to only 75% of patients using contrast. Conclusion: Air pyelogram is a feasible, safe, cost effective and efficient access alternative to contrast pyelogram and in difficult situation a mixture of both is better than using one.

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.

Evaluation of the Risks and Benefits of Computed Tomography Urography for Assessment of Gross Hematuria.

OBJECTIVE: To model the risk of radiation-induced malignancy from computed tomography urography (CTU) in evaluation of gross hematuria and contrast this with the benefits of urinary tract cancer detection when compared to renal ultrasound. METHODS: A PUBMED-based literature search was performed to identify model inputs. Estimates of radiation-induced malignancy rates were obtained from the Biological Effects of Ionizing Radiation VII report with dose extrapolation using the linear no-threshold model. RESULTS: Male gender and age over 50 years were associated with a relative risk of upper tract malignancy of 2.04 and 2.95, respectively. The risk of upper tract malignancy missed by renal ultrasound ranged from 0.055% in females under 50 to 0.51% in males over 50. Risk of CTU-induced malignancy with associated loss of life expectancy ranged from 0.25% and 0.027 years in females under 50 to 0.08% and 0.0054 years in males over 50. For CTU to be superior to renal ultrasound, an undiagnosed upper tract malignancy would have to carry a loss of life expectancy of 49.2 years in females under 50, 13.4 years in males under 50, 2.6 years in females over 50, and 1.1 years in males over 50. CONCLUSION: In low-risk patients, CTU for evaluation of gross hematuria may carry a significant risk of radiation-induced secondary malignancy relative to the diagnostic benefit offered over renal ultrasound.

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.

Imaging response assessment of immunotherapy in patients with renal cell and urothelial carcinoma.

PURPOSE OF REVIEW: Recent advances in anticancer immunotherapy have revolutionized the treatment of metastatic renal cell (RCC) and urothelial carcinoma. In this review, we discuss the mechanisms of action of these new therapeutic approaches, explicate the common adverse events, and highlight different imaging-based response criteria. RECENT FINDINGS: The recent introduction of immune-checkpoint inhibitors led to substantial advances in therapy of metastatic RCC and urothelial carcinoma. Because of the distinct effector mechanisms of these new substances, atypical response patterns such as transient enlargements of tumor lesions, appearance of new lesions after therapy, no measurable decrease in tumor size, or delayed responses are observed in medical imaging studies. This indicates that the established imaging-based response assessment according to the Response Evaluation Criteria in Solid Tumors (RECIST) guidelines has shortcomings to comprehensively evaluate treatment effects. SUMMARY: While monitoring response to immunotherapy still relies on RECIST criteria, immune-related response criteria have been established to better address the imaging changes occurring under immunotherapy. Further studies with long-term follow-up are needed to properly identify and predict response after treatment beyond progression. Because of the expanding clinical use of immune checkpoint inhibitors, radiologists, urologist, and oncologists should be familiar with common imaging findings under this respective therapy.

Assessment of the ability of CT urography with low-dose multi-phasic excretory phases for opacification of the urinary system.

OBJECTIVE: To prospectively evaluate the ability of CT urography with a low-dose multi-phasic excretory phase for opacification of the urinary system. MATERIALS AND METHODS: Thirty-two patients underwent CT urography with low-dose multi-phasic s using adaptive iterative dose reduction 3D acquired at 5-, 10-, and 15-minute delays. Opacification scores of the upper urinary tracts and the urinary bladder were assigned for each excretory phase by two radiologists, who recorded whether adequate (>75%) or complete (100%) opacification of the upper urinary tract and urinary bladder was achieved in each patient. Adequate and complete opacification rates of the upper urinary tracts and the urinary bladder were compared among three excretory phases and among combined multi-phasic excretory phases using Cochran's Q test. RESULTS: There was no significant difference among three excretory phases with 5-, 10-, and 15-minute delays in adequate (56.3, 43.8, and 63.5%, respectively; P = 0.174) and complete opacification rates (9.3, 15.6, and 18.7%, respectively; P = 0.417) of the upper urinary tracts. Combined tri-phasic excretory phases significantly improved adequate and complete opacification rates to 84.4% and 43.8%, respectively (P = 0.002). In contrast, there were significant differences among three excretory phases for the rate of adequate (31.3, 84.4, and 93.8%, respectively; P<0.001) and complete opacification (21.9, 53.1, and 81.3%, respectively; P<0.001) of the urinary bladder. Multi-phasic excretory phases did not improve these rates because opacification was always better with a longer delay. CONCLUSION: Although multi-phasic acquisition of excretory phases is effective at improving opacification of the upper urinary tracts, complete opacification is difficult even with tri-phasic acquisition.

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.

Diagnostic accuracy of computed tomography urography and visual assessment during ureterorenoscopy in upper tract urothelial carcinoma.

OBJECTIVE: To 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 METHODS: Consecutive 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. RESULTS: We 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 (P<0.05). Compared with MCTU, URS had similar sensitivity but significantly greater specificity and accuracy. CONCLUSION: Both 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.

Detection of obstructive uropathy and assessment of differential renal function using two functional magnetic resonance urography tools. A comparison with diuretic renal scintigraphy in infants and children.

AIM: After detection of obstructive uropathy (OU), the indication for or against surgery is primarily based on the differential renal function (DRF). This is to compare functional magnetic resonance urography (fMRU) with dynamic renal scintigraphy (DRS) to assess OU and DRF in infants and children. PATIENTS, METHODS: Retrospective analysis in 30 patients (female: 16; male: 14; median age: 5.5 years [0.2-16.5]), divided into subgroup A (age: 0-2 years; n = 16) and B (> 2-17 years; n = 14). fMRU was assessed by measuring renal transit time (RTT) and volumetric DRF with CHOP fMRU tool (CT) and ImageJ MRU plug-in (IJ). OU detection by fMRU was compared with DRS (standard of reference) using areas under the curves (AUC) in ROC analyses. Concordant DRF was assumed if absolute deviation between fMRU and DRS was ≤ 5 %. RESULTS: DRS confirmed fixed OU in 4/31 kidneys (12.9 %) in subgroup A. AUC of CT was 0.94 compared with 0.93 by IJ. Subgroup B showed fixed OU in 1/21 kidneys (4.8 %) with AUCs of 0.98 each. RTT measured neither by CT nor by IJ in confirmed fixed OU was < 1200 s - resulting in negative predictive values of 1.0 each. In subgroup A, DRF was concordant in 81.3 % of the kidneys for CT and DRS compared with 75.0 % for IJ and DRS. In subgroup B, CT and DRS were concordant in 91.7 %, and IJ and DRS in 45.8 % of the kidneys. CONCLUSION: fMRU accurately excluded fixed OU in infants and children, independent from the software used for quantification. However, assessment of DRF with fMRU deviated from DRS especially in infants who may profit most from early intervention. Thus, fMRU cannot fully replace DRS as primary functional examination. If, for clinical reasons, fMRU is performed in first place and it cannot exclude fixed OU, it should be followed by DRS for validation and DRF quantification.

Assessing the Costs of Extraurinary Findings of Computed Tomography Urogram in the Evaluation of Asymptomatic Microscopic Hematuria.

OBJECTIVE: To assess the costs associated with incidental extraurinary findings on computed tomography urogram (CTU) in patients with asymptomatic microscopic hematuria. MATERIALS AND METHODS: A retrospective review was performed to identify all CTUs performed for asymptomatic microscopic hematuria at our institution from 2012 to 2014. All genitourinary (GU) and incidental extraurinary findings were documented. Further clinical follow-up to May 2015 was reviewed to determine if any referrals, tests, imaging, and/or procedures were ordered based on the initial CTU. Cost estimates were determined using the Medicare physician reimbursement rate. RESULTS: Two hundred two patients were evaluated with CTU for asymptomatic microscopic hematuria. GU malignancy was documented in 2 patients (0.99%), both renal masses suspicious for renal cell carcinoma. Sixty patients were found to have kidney stones, of which 26 had stones ≥5 mm. Incidental extraurinary findings were found in 150 (74.3%) patients, requiring further imaging costs of $17,242 or $85.35 per patient screened. Twelve patients required a total of 20 procedures for a cost of $54,655. The total cost related to extraurinary findings was $140,290 or $694.50 per initial patient screened. CONCLUSION: The incidental extraurinary findings detected on CTU can lead to expensive and invasive testing and treatment. Whereas costs associated with further workup were high, the overall outcomes in both GU and non-GU cancer diagnosis were low. Future analysis should focus on limiting the cost and invasiveness of our evaluation for this condition.

Treatment Response Assessment for Bladder Cancer on CT Based on Computerized Volume Analysis, World Health Organization Criteria, and RECIST.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of our autoinitialized cascaded level set 3D segmentation system as compared with the World Health Organization (WHO) criteria and the Response Evaluation Criteria In Solid Tumors (RECIST) for estimation of treatment response of bladder cancer in CT urography. MATERIALS AND METHODS: CT urograms before and after neoadjuvant chemo-therapy treatment were collected from 18 patients with muscle-invasive localized or locally advanced bladder cancers. The disease stage as determined on pathologic samples at cystectomy after chemotherapy was considered as reference standard of treatment response. Two radiologists measured the longest diameter and its perpendicular on the pre- and posttreatment scans. Full 3D contours for all tumors were manually outlined by one radiologist. The autoinitialized cascaded level set method was used to automatically extract 3D tumor boundary. The prediction accuracy of pT0 disease (complete response) at cystectomy was estimated by the manual, autoinitialized cascaded level set, WHO, and RECIST methods on the basis of the AUC. RESULTS: The AUC for prediction of pT0 disease at cystectomy was 0.78 ± 0.11 for autoinitialized cascaded level set compared with 0.82 ± 0.10 for manual segmentation. The difference did not reach statistical significance (p = 0.67). The AUCs using RECIST criteria were 0.62 ± 0.16 and 0.71 ± 0.12 for the two radiologists, both lower than those of the two 3D methods. The AUCs using WHO criteria were 0.56 ± 0.15 and 0.60 ± 0.13 and thus were lower than all other methods. CONCLUSION: The pre- and posttreatment 3D volume change estimates obtained by the radiologist's manual outlines and the autoinitialized cascaded level set segmentation were more accurate for irregularly shaped tumors than were those based on RECIST and WHO criteria.

Verification of radiation dose calculations during paediatric cystourethrography examinations using MCNP5 and PCXMC 2.0 Monte Carlo codes.

The estimation of the radiological risk in the case of children is of particular importance due to their enhanced radiosensitivity when compared with that of adult patients. The purpose of this study is to estimate the organ and effective doses of paediatric patients undergoing micturating cystourethrography examinations. Since direct measurements of the dose in each organ are very difficult, dose-area products of 90 patients undergoing cystourethrography examinations were recorded and used with two Monte Carlo codes, MCNP5 and PCXMC2.0, to assess the organ doses in these procedures. The organs receiving the highest radiation doses were the urinary bladder (ranging from 1.9 mSv in the newborn to 4.7 mSv in a 5-y old patient) and the large intestines (ranging from 1.5 mSv in the newborn to 3.1 mSv in the 5-y old patient). For all ages the main contributors to the total organ or effective doses are the fluoroscopy projections compared with the radiographs. There was a reasonable agreement between the dose estimates provided by PCXMC v2.0 and MCNP5 for most of the organs considered in this study. In special cases, there were systematic disagreements in organ doses such as in the skeleton, gonads and oesophagus due to the anatomical differences between patient anatomic models employed by the two codes.

Ureteral stenting and retrograde pyelography in the office: clinical outcomes, cost effectiveness, and time savings.

OBJECTIVES: To examine the clinical outcomes and cost-effectiveness of endourologic procedures performed in the office using standard fluoroscopy and topical anesthesia. METHODS: We performed a retrospective review of all patients who underwent primary ureteral stent placement, ureteral stent exchange, or ureteral catheterization with retrograde pyeolography or Bacillus Calmette-Guerin (BCG) instillation under fluoroscopic guidance in the office. For an evaluation of potential time savings, we compared this to a cohort of similar procedures performed in the operating room during the same time period. RESULTS: Procedures were attempted in 65 renal units in 38 patients (13 male, 25 female) with a mean age of 62.2 years (range 29.1-95.4 years). Primary ureteral stent placement was successful in 23/24 (95.8%) renal units. Ureteral stent exchange was successful in 19/22 (86.4%) renal units. Ureteral catheterization with retrograde pyelography or BCG instillation was successful in 19/19 (100%) renal units. The total cost savings for the 38 patients in this study, including excess cost from failure in the office, was approximately $91,496, with an average cost savings of $1,551 per procedure. Office-based procedures were associated with a nearly three-fold reduction in total hospital time as a result of reduced periprocedure waiting times. CONCLUSIONS: Ureteral stent placement, ureteral stent exchange, and ureteral catheterization can be performed safely and effectively in the office in both men and women. This avoids general anesthesia and provides significant savings of time and cost for both patients and the health care system.

MDCT urography with high-volume low-concentration i.v. contrast material, peroral hydration, i.v. furosemide, and i.v. saline: qualitative and quantitative assessment in 100 consecutive patients.

OBJECTIVE: The purpose of this study is to qualitatively and quantitatively assess MDCT urography performed with a high volume of low-concentration (240 mg I/mL) i.v. contrast agent supplemented with peroral hydration, i.v. furosemide, and i.v. saline. MATERIALS AND METHODS: This retrospective evaluation of 100 consecutive normal MDCT urograms was performed for clinical indication of hematuria; patients (76 men and 24 women) were 27-90 years old (mean [± SD] age, 60 ± 15 years). Three radiologists evaluated the degree of opacification across six urinary tract segments (for a total of 1200 measurements per radiologist) on a 4-point scale (0-3). One radiologist measured the maximum short-axis diameter of the proximal, mid, and distal ureters in each patient. Mean opacification scores were calculated for each segment. Radiologist agreement was assessed by kappa coefficient and Spearman rank correlation. Ureteral diameter was correlated to degree of opacification using the Jonckheere-Terpstra trend test. A comparison with published studies using similar scoring methods was undertaken. RESULTS: Of 1200 measured ureteral segments, a total of 24 among the three radiologists were reported as nonopacified. The mean opacification scores ranged from 2.63 ± 0.8 to 3.00 ± 0.8. Calculated kappa coefficients are indicative of substantial agreement (> 0.61). The mean maximal ureteral diameters were 5.44 ± 1.10, 6.32 ± 1.54, and 5.32 ± 1.55 mm for the proximal, mid, and distal ureters, respectively. For all three radiologists, the mean opacification scores increased as distention increased. The Spearman correlation and corresponding p value (p < 0.001) for the association between the distention with the opacification scores show significant correlation. The opacification scores and ureteral distention exceeded published results. CONCLUSION: An MDCT urography technique using high-volume low-concentration i.v. contrast, oral and i.v. hydration, and i.v. diuretic reliably optimizes urinary tract opacification and distention. A positive correlation was found between ureteral distention and opacification.

What the radiologist needs to know about urolithiasis: part 1--pathogenesis, types, assessment, and variant anatomy.

OBJECTIVE: This article reviews types of urinary calculi and their imaging appearances, presents direct and secondary imaging findings of urolithiasis, and provides an overview of treatment methods. Pertinent imaging findings that impact clinical management are highlighted. The implications of complex or variant genitourinary anatomy are reviewed. We outline a standard format for the reporting of urolithiasis to facilitate informed clinical management decisions. CONCLUSION: Unenhanced CT is the preferred examination for evaluation of urolithiasis because of its availability, ease of performance, and high sensitivity. An awareness of the important imaging findings to report allows appropriate and efficient therapy.

Practical value of intravenous urography combined with add-on CT in diagnosing ureteral abnormalities.

BACKGROUND: Intravenous urography (IVU) combined with add-on CT (IVU-CT) can help to provide more diagnostic information for determining the localization and nature of ureteral abnormalities with less irradiation dose. This study aimed to determine the value of IVU-CT for diagnosis of ureteral diseases, where IVU is insufficient to determine the diagnosis. METHODS: Two hundred and eighty patients underwent IVU for suspected ureteral disorders, which identified a definite diagnosis in 184 cases and was insufficient for definite diagnosis in 96 cases designated as indeterminate diagnosis. Subsequently 90 patients (six patients declined CT) with indeterminate diagnosis consented to undergo immediate or delayed helical CT scan. The CT data were transferred to the workstation for post-processing, and the cost and mean effective dose for each imaging method were calculated and compared indirectly. RESULTS: Of the 90 indeterminate diagnosis cases, diagnosis was determined in 86 cases by IVU-CT with a diagnostic accordance rate of 95.6%, while 184/280 (65.7%) had diagnosis determined by IVU alone. There was a significant difference between IVU and IVU-CT in the determination of the diagnosis of ureteral diseases (c(2) = 36.4, P < 0.05). The cost of IVU equals to 1/8 - 1/9 of that for CT urography (CTU), and the cost of IVU-CT is as much as 1/3 of CTU. CTU results in the highest mean effective dose, approximately nine times that for IVU and three times that for IVU-CT. CONCLUSION: IVU-CT provides valuable information for the localization and diagnosis of ureteral abnormalities and may be considered as an efficient, cost-effective and low-dose diagnostic technique in this setting.

Feasibility of low-tube-voltage excretory phase images during CT urography: assessment using a dual-energy CT scanner.

OBJECTIVE: The purpose of this study is to assess the feasibility of low-tube-voltage images during excretory phase CT urography. MATERIALS AND METHODS: In this retrospective study, we examined 70 consecutive CT urograms (35 men and 35 women; mean age, 58.5 years) performed on a dual-energy CT scanner and compared excretory phase images obtained at 80 kVp and 340 mAs with blended images (0.3 × 140 kVp and 80 mAs; and 0.7 × 80 kVp and 340 mAs). Quantitative measurements of urinary system opacification (Hounsfield units), image noise (Hounsfield units), and effective dose (millisieverts) were compared using Student paired t test. Image noise was correlated with patient thickness. Two independent blinded readers qualitatively assessed opacification, image quality (both compared using Wilcoxon test), overall acceptability (compared using McNemar test), and detectability of urinary and extraurinary findings. RESULTS: The 80-kVp images yielded significantly higher opacification of renal pelvis (p < 0.0001), ureter (p < 0.0001), bladder (p < 0.0001), and aorta (p < 0.0001); higher image noise (p < 0.0001); and lower radiation dose (5.2 vs 11.9 mSv). Image noise increased along with increasing patient thickness (r = 0.86 for 80-kVp images). Qualitative opacification scores were better only in the bladder on 80-kVp images (p = 0.002). Although 80-kVp image quality was lower (p < 0.0001), the overall acceptability was similar. Of 42 urinary findings, 40 were detected on 80-kVp images (< 2-mm calyceal calculus and tiny foci of collecting system gas were missed in one patient each, both large patients). Of 137 extraurinary findings, 130 were detected on 80-kVp images (no findings of high clinical significance were missed). CONCLUSION: Low tube voltage (80 kVp) during excretory phase CT urography is feasible, with improved urinary system opacification, acceptable image quality, and lower radiation dose.

Assessment of parental satisfaction in children undergoing voiding cystourethrography without sedation.

PURPOSE: Approximately 50,000 children undergo voiding cystourethrography annually. There is a recent trend toward using sedation or delaying voiding cystourethrography due to the anticipated distress to the patient. We hypothesized that with adequate preparation and proper techniques to minimize anxiety, voiding cystourethrography can be performed without sedation. We assessed parental satisfaction associated with patient and parent experience of voiding cystourethrography without sedation. MATERIALS AND METHODS: We used a 33-question survey to evaluate parental satisfaction with patient and parent experience of voiding cystourethrography without sedation. Children were divided into 3 groups according to toilet training status. Statistical analysis was performed using Stata®. RESULTS: A total of 200 surveys were completed. Of the children 54% were not toilet trained. Of the parents 90% reported adequate preparation. More than half of parents classified the experience of voiding cystourethrography as equivalent to or better than a physical examination, immunization, ultrasound and prior catheterization. Most parents were satisfied with the ability of the child to tolerate the procedure and considered the experience better than expected. Children in the process of toilet training had the most difficulty with the procedure, correlating with lower levels of parental satisfaction. CONCLUSIONS: Voiding cystourethrography performed with adequate preparation and support can be tolerated without sedation. Children in the process of toilet training and females tolerate the procedure least.

Monte Carlo estimation of radiation doses during paediatric barium meal and cystourethrography examinations.

Organ doses are important quantities in assessing the radiation risk. In the case of children, estimation of this risk is of particular concern due to their significant radiosensitivity and the greater health detriment. The purpose of this study is to estimate the organ doses to paediatric patients undergoing barium meal and micturating cystourethrography examinations by clinical measurements and Monte Carlo simulation. In clinical measurements, dose-area products (DAPs) were assessed during examination of 50 patients undergoing barium meal and 90 patients undergoing cystourethrography examinations, separated equally within three age categories: namely newborn, 1 year and 5 years old. Monte Carlo simulation of photon transport in male and female mathematical phantoms was applied using the MCNP5 code in order to estimate the equivalent organ doses. Regarding the micturating cystourethrography examinations, the organs receiving considerable amounts of radiation doses were the urinary bladder (1.87, 2.43 and 4.7 mSv, the first, second and third value in the parentheses corresponds to neonatal, 1 year old and 5 year old patients, respectively), the large intestines (1.54, 1.8, 3.1 mSv), the small intestines (1.34, 1.56, 2.78 mSv), the stomach (1.46, 1.02, 2.01 mSv) and the gall bladder (1.46, 1.66, 2.18 mSv), depending upon the age of the child. Organs receiving considerable amounts of radiation during barium meal examinations were the stomach (9.81, 9.92, 11.5 mSv), the gall bladder (3.05, 5.74, 7.15 mSv), the rib bones (9.82, 10.1, 11.1 mSv) and the pancreas (5.8, 5.93, 6.65 mSv), depending upon the age of the child. DAPs to organ/effective doses conversion factors were derived for each age and examination in order to be compared with other studies.