CT of the urinary tract revisited.

Computed tomography (CT) of the abdomen is usually appropriate for the initial imaging of many urinary tract diseases, due to its wide availability, fast scanning and acquisition of thin slices and isotropic data, that allow the creation of multiplanar reformatted and three-dimensional reconstructed images of excellent anatomic details. Non-enhanced CT remains the standard imaging modality for assessing renal colic. The technique allows the detection of nearly all types of urinary calculi and the estimation of stone burden. CT is the primary diagnostic tool for the characterization of an indeterminate renal mass, including both cystic and solid tumors. It is also the modality of choice for staging a primary renal tumor. Urolithiasis and urinary tract malignancies represent the main urogenic causes of hematuria. CT urography (CTU) improves the visualization of both the upper and lower urinary tract and is recommended for the investigation of gross hematuria and microscopic hematuria, in patients with predisposing factors for urologic malignancies. CTU is highly accurate in the detection and staging of upper tract urothelial malignancies. CT represents the most commonly used technique for the detection and staging of bladder carcinoma and the diagnostic efficacy of CT staging improves with more advanced disease. Nevertheless, it has limited accuracy in differentiating non-muscle invasive bladder carcinoma from muscle-invasive bladder carcinoma. In this review, clinical indications and the optimal imaging technique for CT of the urinary tract is reviewed. The CT features of common urologic diseases, including ureterolithiasis, renal tumors and urothelial carcinomas are discussed.

Fetal uropathies: pre- and postnatal imaging, management and follow-up.

Congenital uropathies are the most common fetal anomalies. They include a wide spectrum of anomalies ranging from mild pelvis dilation to complex urinary tract malformations. Prenatal imaging not only allows for their diagnosis but, in experienced hands, it can differentiate obstructive from refluxing or malformative uropathies. Such precise prenatal information allows for intervention before birth in select cases or for adapting the postnatal workup to provide a better long-term outcome. For the different types of congenital uropathies, we describe their prenatal presentations on US and the complementary role of fetal MRI where indicated. We correlate these findings with postnatal workup and summarize the updated neonatal diagnostic and clinical/surgical management.

Accuracy of transvaginal ultrasound and magnetic resonance imaging for diagnosis of deep endometriosis in bladder and ureter: a meta-analysis.

This meta-analysis aimed to determine the accuracy of transvaginal ultrasound (TVS) and pelvic magnetic resonance imaging (MRI) in diagnosing urinary tract endometriosis (UTE). A comprehensive search of the Pubmed and Embase was conducted between January 1989 and June 2020. Studies that described the accuracy of MRI or TVS for the diagnosis of UTE using surgical data as the reference standard were included. Of the 913 citations identified, 23 studies were analysed. For detection of endometriosis in bladder endometriosis (BE), the overall pooled sensitivities of TVS and MRI were 72% and 68% respectively, and their specificities were 99% and 100% respectively. For detection of endometriosis in the ureteral endometriosis (UE), the overall pooled sensitivities of TVS and MRI were 97% and 87% respectively, and their specificities were both 100%. In conclusion, both TVS and MRI provide good accuracy with specific strong points in diagnosing UTE and seem useful first-line methods from a clinical perspective. Besides, pelvic MRI and TVS are more accurate for predicting UTE localised in the ureter than bladder, especially in terms of sensitivity.IMPACT STATEMENTWhat is already known on this subject? Previous studies have confirmed high diagnostic value of transvaginal ultrasound (TVS) and magnetic resonance imaging (MRI) on bladder endometriosis (BE) respectively. However, high heterogeneity was found for both sensitivity and specificity and no meta-analysis has yet been performed to test the diagnostic value of TVS and MRI for ureteral endometriosis (UE).What the results of this study add? In this meta-analysis, we firstly confirmed high diagnostic value of TVS and MRI on UE respectively. For detection of UE, the overall pooled sensitivities of TVS and MRI were 97% and 87% respectively, and their specificities were both 100%.What the implications are of these findings for clinical practice and/or further research? Early preoperative diagnosis and accurate understanding of the widespread distribution of endometriosis are prerequisites for radical surgical in UTE. In the present study, we updated the previous results on the accuracy of TVS and MRI for the diagnosis of BE and firstly confirmed high diagnostic value of TVS and MRI on UE. Both TVS and MRI provide good accuracy with specific strong points in diagnosing UTE and seem useful first-line methods from a clinical perspective.

[Modern tomography imaging techniques in urological diseases]. / Moderne Schnittbildgebung für urologische Erkrankungen.

BACKGROUND: Radiologic imaging is important for the detection, staging and follow-up of urological tumors. Basic therapy decisions for both oncological (surgical vs. systemic therapy, e.g. in testicular cancer) and non-oncological pathologies (interventional vs. conservative therapy, e.g. for ureteral stones) depend largely on the tomographic imaging performed. Due to its almost ubiquitous availability, speed and cost-effectiveness, computed tomography (CT) plays an important role not only in the clarification of abdominal trauma and non-traumatic emergencies, but also in staging and follow-up of oncological patients. However, the level of radiation exposure, impaired renal function and allergies to iodinated contrast media limit the use of CT. Magnetic resonance imaging (MRI) can be a good alternative for many areas of application in oncological and non-oncological imaging due to its high soft tissue differentiation and functional-specific protocols but without the use of ionizing radiation. AIM: In the following, the main indications of abdominal and pelvic CT and MRI in urology and their limitations are summarized. RESULTS: The areas of application between CT and MRI are increasingly overlapping, since the latest developments in CT continue to further reduce radiation exposure and increase contrast information, while the speed and robustness of MRI are significantly improving at the same time.

Imposibilidad para el sondaje vesical: siringocele de Cowper / Impossibility for bladder catheterization: Cowper's syringocele

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Imaging of acute pelvic pain.

Acute pelvic pain (APP) requires urgent medical evaluation and treatment. Differential diagnosis of APP is broad, including a variety of gynecologic and non-gynecologic/ urinary, gastrointestinal, vascular and other entities. Close anatomical and physiological relations of pelvic structures, together with similar clinical presentation of different disorders and overlapping of symptoms, especially in the emergency background, make the proper diagnosis of APP challenging. Imaging plays a crucial role in the fast and precise diagnosis of APP. Ultrasonography is the first-line imaging modality, often accompanied by CT, while MRI is utilized in specific cases, using short, tailored protocols. Recognizing the cause of APP in females is a challenging task, due to the wide spectrum of possible origin and overlap of their imaging features. Therefore, the radiologist has to be familiar with the possible causes of APP, and, relying on clinical presentation, together with laboratory findings, choose the best imaging strategy in order to establish a fast and accurate diagnosis.

Focused Ultrasound Examination of Canine and Feline Emergency Urinary Tract Disorders.

This article discusses the usefulness of ultrasound examinations in the management of the patient with an emergency urinary tract disorder. It discusses the use of previously described point-of-care ultrasound protocols such as the abdominal focused assessment with sonography for trauma, triage, and tracking protocol in the unstable azotemic patient. Point-of-care ultrasound examination can help direct investigations and expedite the diagnosis of specific causes of azotemia. The limitations of point-of-care ultrasound assessment of the kidneys, ureter, bladder, and urethra are also addressed, emphasizing that point-of-care ultrasound examination should complement and not replace a complete urinary tract ultrasound examination.

Comparison of Conventional and Triple Bolus Computerized Tomographic Urography Protocols for Radiation Dose Reduction in Hematuria Evaluation: A Randomized Controlled Trial.

PURPOSE: Computerized tomographic urography is the diagnostic tool of choice for evaluating hematuria. In keeping with the ALARA (As Low As Reasonably Achievable) principle, we evaluated a triple bolus computerized tomography protocol designed to reduce radiation exposure. MATERIALS AND METHODS: Patients with macroscopic or microscopic hematuria were prospectively randomized to conventional computerized tomography (100) or triple bolus computerized tomography (100). The triple bolus computerized tomography protocol entails 2 scans: pre-contrast scan followed by 3 contrast injections at 40 seconds, 60 seconds and 20 minutes prior to the second scan to capture all 3 phases. The conventional computerized tomography protocol requires 4 scans: pre-contrast scan, and 3 post-contrast scans at the corticomedullary, nephrographic and excretory phases. Radiation exposure and the detection of urological pathology were recorded based on radiology reports. RESULTS: There were no differences in patient demographics or body mass index between the 2 groups. Triple bolus computerized tomography exposed patients to 33% less radiation (1,715 vs 1,145 mGy*cm for conventional vs triple bolus computerized tomography; p <0.001). For macroscopic hematuria, the pathology detection rates were 70% for triple bolus and 73% for conventional computerized tomography (p=0.72). For microscopic hematuria, the detection rates were 59% for triple bolus and 50% for conventional computerized tomography (p=0.68). In both groups, the rates of detection of urolithiasis, renal cysts, urological masses, bladder pathology and prostate pathology were no different between triple bolus and conventional computerized tomography. CONCLUSIONS: In both the settings of macroscopic and microscopic hematuria evaluation, triple bolus computerized tomography significantly reduces radiation exposure while providing equivalent detection of genitourinary pathology compared to conventional computerized tomography. The ability to detect upper tract filling defects was not specifically tested.

Low-dose CT urography using deep learning image reconstruction: a prospective study for comparison with conventional CT urography.

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.

Abdominal Imaging Manifestations of Recreational Drug Use.

Recreational drug use is a burgeoning health issue worldwide, with a variety of presenting symptoms and complications. These complications can be secondary to the toxic effects of the drug itself, drug impurities, and nonsterile injection. The abdominal radiologist is likely to encounter patients who use drugs recreationally and may be responsible for recognizing and reporting these acute conditions, which in some cases can be life threatening. Because these patients often present with an altered mental state and may deny or withhold information on drug use, the underlying cause may be difficult to determine. The most commonly used drugs worldwide include cocaine, cannabinoids, opioids, and amphetamines and their derivatives. Complications of use of these drugs that can be seen at abdominopelvic CT can involve multiple organ systems, including the soft tissue and gastrointestinal, genitourinary, vascular, and musculoskeletal systems. A diverse range of abdominal complications associated with these drugs can be seen at imaging, including disseminated infections, gastrointestinal ischemia, and visceral infarction. Radiologists should be familiar with the imaging findings of these complications to accurately diagnose these entities and help guide workup and patient treatment. ©RSNA, 2020.

Ultra-high-resolution CT urography: Importance of matrix size and reconstruction technique on image quality.

PURPOSE: 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. METHOD: 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. RESULTS: 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). CONCLUSIONS: CTU with a 1024-matrix and model-based IR depicted the structures of the urinary system in the most detail.

Non-18F-Fluorodeoxyglucos PET Tracers in Pediatric Disease.

18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) is an efficient method of diagnosing, staging, treatment evaluation, and recurrence monitoring of pediatric diseases. FDG has some limitations, but other PET/CT tracers have shown promising roles in evaluation of pathologies in pediatric patients. FDG is the most commonly used PET tracer but can accumulate in different types of infection and inflammation. In recent years, more non-FDG tracers have shown utility in evaluating pediatric disease. This article reviews currently available literature on the clinical application of non-FDG PET tracers in the application in the pediatric population.

No evidence for the need of a routine renal transplant ultrasound after elective transplant ureteric stent removal-A retrospective cohort study.

Transplant ureteric stent insertion reduces the incidence of MUCs, but it is not known whether routine PSRGU is needed to detect unmasked MUCs. This study evaluated whether routine PSRGU in the pRTR is a useful tool to identify MUCs before they become clinically apparent. A retrospective analysis was undertaken of the clinical outcomes following elective stent removal from pediatric kidney-only transplant recipients at two London centers between 2012 and 2016. Our policy was to perform PSRGU either routinely or urgently if there were concerning symptoms or biochemical evidence of renal allograft dysfunction. Elective stent removal was performed in 86% (97 of 113 pRTR), and 75 (77%) of whom had routine PSRGU at a median (IQR) of 6 (2-8) days after stent removal. There were changes to management in 3 (4%) of pRTR with PSRGU identifying no MUC. Nineteen patients (25%) had urgent PSRGU, most commonly due to renal allograft dysfunction, at a median (IQR) of 5.5 (2.7-12.3) days after stent removal. Of these, two pRTR required ureteric intervention. For our current practice of removing transplant stents at 4-6 weeks post-transplantation, our study has found no evidence to support routine PSRGU after elective stent removal.

Urinary Tract Bleeding as a Rare Manifestation of Uterine Artery Pseudoaneurysm.

Pseudoaneurysm of the uterine artery is a rare condition, which usually occurs after a traumatic birth, cesarean section, dilatation and curettage, and hysterectomy. This case is a 28-year-old female patient that presented with the chief complaint of severe urinary tract bleeding and hypovolemic shock. This patient underwent cesarean section 2 months before the first presentation. After the primary examination, the patient was sent to the hybrid operation room with the primary diagnosis of uterine artery pseudoaneurysm and coil embolization was done for treating the pseudoaneurysm. Considering continued bleeding, open surgery was performed and the internal iliac artery was ligated.

Patient Preparation and Patient-related Challenges with FDG-PET/CT in Infectious and Inflammatory Disease.

Several factors that influence physiologic 18F-fluorodeoxyglucose (FDG) uptake and general FDG distribution may affect PET/CT imaging in infection and inflammation. The general impact of hyperglycemia on the diagnostic performance of FDG-PET/CT is probably less in infection/inflammation than in malignancy. Patient preparation may reduce physiologic FDG uptake, but recommendations are less established than in malignancy. Local implementation of various patient preparatory measures should reflect the specific patient population and indications. This article outlines some of the challenges with physiologic FDG distribution, focusing on infectious and inflammatory diseases, and potential countermeasures and patient preparation to limit physiologic uptake before scan.

[Indocyanine green fluorescence to visualize the ureteric vascularization of kidney transplants: An exploratory study]. / Visualiser la vascularisation urétérale des transplants rénaux par fluorescence au vert d'indocyanine : étude exploratoire.

INTRODUCTION: Urinary complications after kidney transplantation are common and can compromise renal function. While they are mainly attributed to ischemic lesions of the ureter, there is no existing method to evaluate its vascularization during surgery. The aim of the study was to evaluate if indocyanine green, revealed by infra-red light andused to visualize tissue perfusion, could provide an appreciation of the ureter's vascularization during kidney transplantation. METHODS: This feasibility study was conducted over one month, on eleven consecutive kidney transplants. During transplantation, an injection of indocyanine green enabled the surgeon to visualize in real time with an infra-red camera the ureter fluorescence. Its intensity was reported on a qualitative and semi-quantitative scale. Occurrence of urinary complications such as stenosis or ureteral fistula were collected during 6 months. RESULTS: In all of the 11 cases (100%), the last centimeters of the ureters were not fluorescent. Three (27%) ureters were poorly or partiallly fluorescent. Out of these three cases, only one case of urinary fistula occurred, followed by ureteric stenosis. In the series, two fistulas (18%) and two ureteric stenoses (18%) occurred. No side effects were observed. The low number of events did not allow statistical analysis. CONCLUSION: Infra-red fluorescence of indocyanine green could be a simple and innovative way to appreciate the transplant's ureteric vascularization during kidney transplantation. It could help surgeons to identify the level of ureter section and to decide the anastomosis technique, in order to limit urinary complications. LEVEL OF EVIDENCE: 3.