ACR Appropriateness Criteria® Hematuria

Urologic Imaging of the Bladder: Cancers and Mimics

Bladder cancer (BC) represents a significant global health challenge with notable incidence and mortality rates. Despite treatment advancements, its management remains complex, requiring a multidisciplinary approach. Imaging techniques play a pivotal role in diagnosis, staging, and treatment planning by aiding lesion localization, differentiation, and assessment of tumor extent. Primary modalities like computed tomography and MRI offer detailed anatomic insights. Imaging provides valuable insights into tumor biology, vascular patterns, and molecular profiles, enabling personalized medicine strategies to optimize therapeutic efficacy and minimize adverse effects, crucial for improving BC management and prognosis.

ACR Appropriateness Criteria® Pretreatment Staging of Urothelial Cancer: 2024 Update

Urothelial cancer is the second most common cancer, and cause of cancer death, related to the genitourinary tract. The goals of imaging for pretreatment staging of urothelial cancer are to evaluate for both local and distant spread of the cancer and assessing for synchronous sites of urothelial cancer in the upper tracts and bladder. For pretreatment staging of urothelial carcinoma, patients can be stratified into one of three groups: 1) nonmuscle invasive bladder cancer; 2) muscle invasive bladder cancer; and 3) upper urinary tract urothelial carcinoma. This document is a review of the current literature for urothelial cancer and resulting recommendations for pretreatment staging imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Canadian Association of Radiologists Genitourinary Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Genitourinary Expert Panel is made up of physicians from the disciplines of radiology, emergency medicine, family medicine, nephrology, and urology, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 22 clinical/diagnostic scenarios, a rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 30 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 65 recommendation statements across the 22 scenarios (2 scenarios point to the CAR Obstetrics and Gynecology Diagnostic Imaging Referral Guideline). This guideline presents the methods of development and the referral recommendations for haematuria, hypertension, renal disease (or failure), renal colic, renal calculi in the absence of acute colic, renal lesion, urinary tract obstruction, urinary tract infection, scrotal mass, or pain, including testicular torsion, adrenal mass, incontinence, urgency, and frequency, chronic pelvic pain, elevated PSA, infertility, and pelvic floor.

Is the excretory phase necessary to identify upper tract urothelial neoplasms at CT urography? A 10-year population-based study

PURPOSE

To assess the proportion of upper tract urothelial carcinomas (UTUC) that are evident without the excretory phase at CT urography (CTU), and the proportion of potentially avoidable radiation.

METHODS

UTUCs diagnosed between January 2008-December 2017 were retrospectively identified from a population-based cancer registry. For each patient, US, non-urographic CT, and MRI exams were assessed for a primary mass and secondary imaging findings (hydronephrosis, urinary tract thickening, luminal distention, fat stranding, and lymphadenopathy/metastatic disease). CTUs were assessed for primary and secondary findings, and whether the tumor was evident as a filling defect on excretory phase. The dose-length product (DLP) of potentially avoidable excretory phases was calculated as a fraction of total DLP.

RESULTS

288 patients (mean age, 72±11 years, 165 males) and 545 imaging examinations were included. Of 192 patients imaged with 370 non-urographic CTs, a primary mass was evident in 154 (80.2%), secondary findings were evident in 172 (89.6%), and primary or secondary findings were evident in 179 (93.2%). Of 175 CTUs, primary and secondary findings were evident in 157 (89.7%) and 166 (94.9%) examinations, respectively, and primary or secondary findings were evident in 170/175 (97.1%). 131/175 (74.9%) UTUCs were evident as a filling defect, including the 5/175 (2.9%) UTUCs without primary or secondary findings. Of 144 CTUs with available DLP data, the proportion of potentially avoidable radiation was 103.7/235.8 (44.0%) Gy⋅cm.

CONCLUSION

In our population, almost all UTUCs were evident via primary or secondary imaging findings without requiring the excretory phase. These results support streamlining protocols and pathways.

Discrepant guidelines in the evaluation of hematuria

PURPOSE

To assess discrepancies in current imaging recommendations for hematuria among North American societies: American College of Radiology (ACR), American Urological Association (AUA), and Canadian Urological Association (CUA).

METHODS

The latest available ACR Appropriateness Recommendations, AUA guidelines, and CUA guidelines were reviewed. AUA and CUA guidelines imaging recommendations by variants and level of appropriateness were converted to match the style of ACR. Imaging recommendations including modality, anatomy, and requirement for contrast were recorded.

RESULTS

Clinical variants included microhematuria without risk factors, microhematuria with risk factors, gross hematuria, and microhematuria during pregnancy. CUA recommends ultrasound kidneys as the first-line imaging study in the first 3 variants; pregnancy is not explicitly addressed. For hematuria without risk factors, ACR does not routinely recommend imaging, while AUA recommends shared decision-making to decide repeat urinalysis versus cystoscopy with ultrasound kidneys. For hematuria with risk factors and gross hematuria, ACR recommends CT urography; MR urography can also be considered in gross hematuria. AUA further stratifies intermediate- and high-risk patients, for which ultrasound kidneys and CT urography are recommended, respectively. For pregnancy, ACR and AUA both recommend ultrasound kidneys, though AUA additionally recommends consideration of CT or MR urography after delivery.

CONCLUSION

There is no universally agreed upon algorithm for diagnostic evaluation. Discrepancies centered on the role of upper tract imaging with ultrasound versus CT. Prospective studies and/or repeat simulation studies that apply newly updated guidelines are needed to further clarify the role of imaging, particularly for patients with microhematuria with no and intermediate risk factors.

Computed Tomography Urography: State of the Art and Beyond

Computed Tomography Urography (CTU) is a multiphase CT examination optimized for imaging kidneys, ureters, and bladder, complemented by post-contrast excretory phase imaging. Different protocols are available for contrast administration and image acquisition and timing, with different strengths and limits, mainly related to kidney enhancement, ureters distension and opacification, and radiation exposure. The availability of new reconstruction algorithms, such as iterative and deep-learning-based reconstruction has dramatically improved the image quality and reducing radiation exposure at the same time. Dual-Energy Computed Tomography also has an important role in this type of examination, with the possibility of renal stone characterization, the availability of synthetic unenhanced phases to reduce radiation dose, and the availability of iodine maps for a better interpretation of renal masses. We also describe the new artificial intelligence applications for CTU, focusing on radiomics to predict tumor grading and patients' outcome for a personalized therapeutic approach. In this narrative review, we provide a comprehensive overview of CTU from the traditional to the newest acquisition techniques and reconstruction algorithms, and the possibility of advanced imaging interpretation to provide an up-to-date guide for radiologists who want to better comprehend this technique.

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.

ACR Appropriateness Criteria® Acute Pyelonephritis: 2022 Update

Acute pyelonephritis (APN) is a severe urinary tract infection (UTI) that has the potential to cause sepsis, shock, and death. In the majority of patients, uncomplicated APN is diagnosed clinically and is responsive to treatment with appropriate antibiotics. In patients who are high risk or when treatment is delayed, microabscesses may coalesce to form an acute renal abscess. High-risk patients include those with a prior history of pyelonephritis, lack of response to therapy for lower UTI or for APN, diabetes, anatomic or congenital abnormalities of the urinary system, infections by treatment-resistant organisms, nosocomial infection, urolithiasis, renal obstruction, prior renal surgery, advanced age, pregnancy, renal transplant recipients, and immunosuppressed or immunocompromised patients. Pregnant patients and patients with renal transplants on immunosuppression are at an elevated risk of severe complications. Imaging studies are often requested to aid with the diagnosis, identify precipitating factors, and differentiate lower UTI from renal parenchymal involvement, particularly in high-risk individuals. Imaging is usually not appropriate for the first-time presentation of suspected APN in an uncomplicated patient. The primary imaging modalities used in high-risk patients with suspected APN are CT, MRI, and ultrasound, although CT was usually not appropriate for initial imaging in a pregnant patient with no other complications. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

CT-urography: a nationwide survey by the Italian Board of Urogenital Radiology

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

Urothelial Carcinoma of the Bladder: Radiologic Perspective

방광암은 비교적 흔히 진단되는 암이며 재발이 흔해 영상의학적 검사에서 흔히 만날 수 있다. 방광암의 정확한 진단과 병기 평가는 어떤 치료를 할 것인지를 정하고 예후를 평가하는데 큰 영향을 미친다. 방광암의 임상적 병기 평가는 요도경유방광종양절제술로 진단과 치료를 겸해서 이루어졌지만, 저평가되는 경우가 흔히 있다. 수술 전 방광암의 위치, 크기, 근육층 침범 유무, 림프절전이, 원격전이, 상부요로 암 유무 등을 영상의학적 검사에서 정확히 진단 및 평가할 수 있다면 더욱 적절히 처치 및 관리를 할 수 있다. 이런 정확한 진단을 위해서는 영상을 판독하는 영상의학과 의사는 먼저 방광암의 임상적인 특징을 잘 알고 있어야 한다. 그리고 영상 검사들의 종류와 특징, 한계를 알고 있어야 한다. 최근 자기공명영상의 발달로 방광 영상의 질 및 방광암의 진단과 평가가 향상되었다. 그리고 방광 이미징 보고 및 데이터시스템이 발표되어 객관적으로 방광암의 근육층 침범 가능성을 평가할 수 있게 되었다. 방광암 치료 종류를 알고 그에 따른 치료 후 변화에는 무엇이 있는지 어떻게 평가하는지도 알아야 하겠다. 이 종설에서는 방광 요로상피세포암의 특징과 다양한 영상의학 검사와 소견에 대해서 알아보고자 한다.

The Role of Imaging in Bladder Cancer Diagnosis and Staging

Bladder cancer (BC) is the most common cancer of the urinary tract in the United States. Imaging plays a significant role in the management of patients with BC, including the locoregional staging and evaluation for distant metastatic disease, which cannot be assessed at the time of cystoscopy and biopsy/resection. We aim to review the current role of cross-sectional and molecular imaging modalities for the staging and restaging of BC and the potential advantages and limitations of each imaging modality. CT is the most widely available and frequently utilized imaging modality for BC and demonstrates good performance for the detection of nodal and visceral metastatic disease. MRI offers potential value for the locoregional staging and evaluation of muscular invasion of BC, which is critically important for prognostication and treatment decision-making. FDG-PET/MRI is a novel hybrid imaging modality combining the advantages of both MRI and FDG-PET/CT in a single-setting comprehensive staging examination and may represent the future of BC imaging evaluation.

Update on Hereditary Renal Cancer and Imaging Implications

Up to 8% of renal cancers are thought to have a hereditary component. Several hereditary renal cancer syndromes have been identified over the last few decades. It is important for the radiologist to be aware of findings associated with hereditary renal cancer syndromes to detect tumors early, enroll patients in appropriate surveillance programs, and improve outcomes for the patient and affected family members. This review discusses from a radiologist's perspective well-known hereditary renal cancer syndromes and emerging genetic mutations associated with renal cancer that are less well characterized, focusing on imaging features and known associations.