Imaging Patients with Kidney Failure.

The approach to imaging a patient with kidney failure continues to evolve. Overstatement of the risk of iodinated contrast material-induced (ie, contrast-induced) acute kidney injury and new guidelines for administration of gadolinium-based contrast media affect screening and the choice of contrast material. Treatment of kidney failure requires dialysis or a kidney transplant. Pretransplant imaging includes assessment for the feasibility of performing a transplant and evaluation for underlying malignancy and peripheral vascular disease. Patients with kidney failure are at high risk for renal cell carcinoma. Subtypes that occur exclusively or more commonly in patients with kidney failure, such as acquired cystic kidney disease, renal cell carcinoma, and clear cell papillary renal cell carcinoma, have specific clinical-pathologic characteristics, with indolent behavior. Performing US for dialysis planning increases the success of placement of an arteriovenous fistula, while postoperative US evaluation is essential in assessment of access dysfunction. Systemic manifestations in patients with kidney failure are multifactorial and may relate to the underlying cause of renal failure or may be secondary to treatment effects. Disturbances in mineral and bone metabolism and soft-tissue and vascular calcifications are seen in patients with chronic kidney disease and mineral bone disorder. Neurologic and cardiothoracic complications are also common. The authors provide a comprehensive overview of imaging considerations for patients with kidney failure, including the appropriate use of CT, MRI, and US with their respective contrast agents; the use of imaging in transplant workup and dialysis assessment; and the common renal and extrarenal manifestations of kidney failure. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Clinical outcome following checkpoint therapy in renal cell carcinoma is associated with a burst of activated CD8 T cells in blood.

PURPOSE: Checkpoint therapy is now the cornerstone of treatment for patients with renal cell carcinoma (RCC) with advanced disease, but biomarkers are lacking to predict which patients will benefit. This study proposes potential immunological biomarkers that could developed for predicting therapeutic response in patients with RCC. METHODS: Using flow cytometry, RNA sequencing, and T-cell receptor (TCR) sequencing, we investigated changes in T cells in the peripheral blood of patients with advanced RCC after receiving immunotherapy. We used immunofluorescence (IF) imaging and flow cytometry to investigate how intratumoral T cells in patients' tumors (resected months/years prior to receiving checkpoint therapy) predicted patient outcomes after immunotherapy. RESULTS: We found that a small proportion of CD4 and CD8 T cells in the blood activate following checkpoint therapy, expressing the proliferation marker Ki67 and activation markers HLA-DR and CD38. Patients who had the highest increase in these HLA-DR +CD38+CD8 T cells after treatment had the best antitumor immune response and experienced clinical benefit. Using RNA sequencing, we found that while these cells expanded in most patients, their phenotype did not drastically change during treatment. However, when we analyzed the TCR repertoire of these HLA-DR +CD38+CD8+T cells, we found that only patients who clinically benefitted had a burst of new clonotypes enter this pool of activated cells. Finally, we found that abundant T cells in the untreated tumors predicted clinical benefit to checkpoint therapy on disease progression. CONCLUSIONS: Together, these data suggest that having a strong pre-existing immune response and immediate peripheral T-cell activation after checkpoint therapy is a predictor of clinical benefit in patients with RCC.

Implementation of peer learning conferences throughout a multi-site abdominal radiology practice.

PURPOSE: To initiate a peer learning conference for our abdominal radiology division across multiple geographically separated sites and different time zones, and to determine radiologist preference for peer learning versus traditional score-based peer review. METHODS: We implemented a monthly peer learning videoconference for our abdominal radiology division. Surveys regarding radiologist opinion regarding traditional peer review and the new peer learning conferences were conducted before and after 6 months of conferences. RESULTS: Peer learning conferences were well attended across our multiple sites, with an average of 43 participants per conference. Radiologist opinion regarding peer review was poor, with survey radiologists responding positively to only 1 out of 12 process questions. Opinion regarding peer learning was extremely favorable, with radiologists responding positively to 12 out of the same 12 process questions. After 6 months of peer learning conferences, 87.9% of surveyed radiologists wished to continue them in some fashion, and no one preferred to return to score-based peer review alone. CONCLUSION: We successfully implemented a peer learning conference for our abdominal radiology division spread out over multiple geographic sites. Our radiologists strongly preferred peer learning conferences over our traditional peer review system for quality control.

Current Status and Future Wish List of Peer Review: A National Questionnaire of U.S. Radiologists.

OBJECTIVE. Most peer review programs focus on error detection, numeric scoring, and radiologist-specific error rates. The effectiveness of this method on learning and systematic improvement is uncertain at best. Radiologists have been pushing for a transition from an individually punitive peer review system to a peer-learning model. This national questionnaire of U.S. radiologists aims to assess the current status of peer review and opportunities for improvement. MATERIALS AND METHODS. A 21-question multiple-choice questionnaire was developed and face validity assessed by the ARRS Performance Quality Improvement subcommittee. The questionnaire was e-mailed to 17,695 ARRS members and open for 4 weeks; two e-mail reminders were sent. Response collection was anonymous. Only responses from board-certified, practicing radiologists participating in peer review were analyzed. RESULTS. The response rate was 4.2% (742/17,695), and 73.7% (547/742) met inclusion criteria. Most responders were in private practice (51.7%, 283/547) with a group size of 11-50 radiologists (50.5%) and in an urban setting (61.6%). Significant diversity was noted in peer review systems, with RADPEER used by less than half (45.0%) and cases selected most commonly by commercial software (36.2%) or manually (31.2%). There was no consensus on the number of required peer reviews per month (10-20 cases, 32.1%; > 20 cases, 29.1%; < 10 cases, 21.7%). Less than half (43.7%) did not use peer review for group education. Whereas most (67.7%) were notified of their peer review results individually, 21.5% were not notified at all. Around half were dissatisfied (44.5%) because of insufficient learning (94.0%) and inaccurate representation of their performance improvement (75.5%). Overall, the group discrepancy rates were unknown to most radiologists who participate in peer review (54.3%). Submission bias was the main reason for underreporting of serious discrepancies (49.0%). Most found four peer-learning methods feasible in daily practice: incidental observation, 65.1%; focused practice review, 52.9%; professional auditing, 45.8%; and blinded double reading, 35.4%. CONCLUSION. More than half of participants reported that peer review data are used for educational purposes. However, significant diversity remains in current peer review practice with no agreement on number of required reviews, method of case selection, and oversight of results. Nearly half of the radiologists reported insufficient learning, although most feel a better system would be feasible in daily practice.

Ramucirumab and Docetaxel in Patients with Metastatic Urothelial Carcinoma Harboring Fibroblast Growth Factor Receptor Alterations: A Case Series and Literature Review.

Metastatic urothelial carcinoma (mUC) has a poor prognosis with a 5-year survival probability of 4.8%. The mainstay of first-line treatment is platinum-based chemotherapy. Second-line therapy involves immune checkpoint inhibitors or a fibroblast growth factor receptor (FGFR) inhibitor, erdafitinib, for patients harboring selected FGFR alterations. Several additional agents are under development for the treatment of mUC. Recent studies demonstrate that ramucirumab and docetaxel have clinical activity in mUC. We report two patients with metastatic upper tract urothelial cancer (mUTUC) with FGFR alterations who were heavily pretreated with FGFR inhibitors that later showed response to ramucirumab and docetaxel. Preclinical studies indicate that FGF and VEGF pathways work synergistically, which could explain the observations in our patients. Our findings may represent another treatment option for patients with mUC and FGFR alterations who have progressed on multiple lines of therapy.

Cultivating Future Radiology Educators: Development and Implementation of a Clinician-Educator Track for Residents.

Effective and dedicated educators are critical to the preservation and advancement of the practice of radiology. The need for innovative and adaptable educators is increasingly being recognized, with several institutions granting academic promotions through clinician-educator tracks. The implementation of resident "clinician-educator tracks" or "teaching tracks" should better prepare residents aspiring to become academic radiologists focused on teaching. In this work, we describe our experience in the development and implementation of a clinician-educator track for diagnostic radiology residents at our institution.

Spectrum of Extratesticular and Testicular Pathologic Conditions at Scrotal MR Imaging.

Diagnostic workup of scrotal lesions should begin with a complete clinical history and physical examination, including analysis of risk factors such as family history of testicular cancer, personal history of tumor in the contralateral testis, and cryptorchidism, followed by imaging. Scrotal ultrasonography (US) with a combination of gray-scale and color Doppler techniques has been the first-line imaging modality for evaluation of testicular and extratesticular lesions because of its low cost, wide availability, and high diagnostic accuracy. However, US has limitations related to operator dependence, the relatively small field of view, and lack of tissue characterization. Magnetic resonance (MR) imaging, because of its superior soft-tissue contrast and multiplanar capabilities, is increasingly being used as a supplemental diagnostic problem-solving tool in cases where scrotal US findings are inconclusive or nondiagnostic. In addition to morphology, lesion location, and tissue characterization (eg, fat, blood products, granulation tissue, and fibrosis), scrotal MR imaging provides important information that can affect surgical planning and improve patient care. MR imaging also is helpful for differentiating testicular and extratesticular lesions, distinguishing between benign and malignant lesions, and evaluating the local extent of disease. This review discusses the anatomy and MR imaging features of testicular and extratesticular neoplastic and nonneoplastic conditions and describes relevant MR imaging techniques. ©RSNA, 2018 Contact information that appeared in the print version of this article was updated in the online version on May 14, 2018.

Management of the Incidental Renal Mass on CT: A White Paper of the ACR Incidental Findings Committee.

The ACR Incidental Findings Committee (IFC) presents recommendations for renal masses that are incidentally detected on CT. These recommendations represent an update from the renal component of the JACR 2010 white paper on managing incidental findings in the adrenal glands, kidneys, liver, and pancreas. The Renal Subcommittee, consisting of six abdominal radiologists and one urologist, developed this algorithm. The recommendations draw from published evidence and expert opinion and were finalized by informal iterative consensus. Each flowchart within the algorithm describes imaging features that identify when there is a need for additional imaging, surveillance, or referral for management. Our goal is to improve quality of care by providing guidance for managing incidentally detected renal masses.

Assessment of Added Value of Noncontrast to Contrast-Enhanced Abdominal Computed Tomography Scan for Characterization of Hypervascular Liver Metastases.

Assess the added value of nonenhanced computed tomography (NECT) to contrast-enhanced CT (CECT) of the abdomen for characterization of hypervascular liver metastases and incidental findings. Institutional review board approved, Health Insurance Probability and Accountability Act compliant, retrospective study of patients with melanoma, neuroendocrine tumor, or thyroid cancer. First available triphasic abdomen CT after initial diagnosis was reviewed by 3 radiologists. The 3 most suspicious lesions were characterized on the CECT as benign or malignant and then recharacterized after reviewing the NECT with CECT. Incidental renal and adrenal lesions were characterized similarly. Diagnostic performance of CECT vs its combination with NECT was assessed. Statistical significance level was set at P < 0.05. A total of 81 patients were included (mean age = 55 years; 52% male; 64% with liver lesions; 27% and 11% with incidental renal and adrenal lesions, respectively). Percentage area under the curve and 95% CI of CECT vs combination with NECT for characterization of liver metastases was 98(94-100) vs 99(96-100) for reviewer 1 (P = 0.35), 93(86-100) vs 94(87-100) for reviewer 2 (P = 0.23), and 96(90-100) vs 99(97-100) for reviewer 3 (P = 0.32). Mean difference in area under the curve and 95% CI between 2 protocols for characterization of liver, renal, and adrenal lesions were -0.007(-0.05 to 0.04) (P = 0.63), -0.09(-0.25 to 0.07) (P = 0.22), and -0.01(-0.05 to 0.02) (P = 0.27), respectively. After addition of NECT, confidence level for lesion characterization increased 4%-15% for liver metastases, 18%-59% and 33%-67% for renal and adrenal lesions, respectively. In conclusion, while addition of NECT to CECT improved radiologist' confidence, there was no statistically significant change in characterization of hypervascular liver metastases or incidental renal and adrenal lesions.

Optimal section thickness for detection of polyps at MR: resolution phantom study.

PURPOSE: To determine (1) the sensitivity for detection of small polyps with varying MR slice thicknesses using a resolution phantom; (2) reader confidence in polyp detection; and (3) image acquisition time. METHODS: A resolution phantom was created using a 3D printer. Polyp morphologies were sessile (height = diameter), flat (height = 1/2 diameter of the base), and pedunculated (stalk length = polyp diameter). Polyp diameters were 5, 7, 10, and 12 mm. Images were acquired with section thicknesses of 5, 3, and 1 mm. Images were independently reviewed by 4 board-certified radiologists who were blinded to phantom design and sequences parameters. Readers recorded maximal polyp diameter and confidence level that a polyp was present on a 1-100 point scale. Image acquisition time was also recorded. RESULTS: All polyps were detected by all 4 readers in the 5-mm-section thickness series. All polyps were detected by 3 readers in the 3- and 1-mm-section thickness series. The fourth reader identified 11/12 polyps in the 3- and 1-mm-section thickness series. Confidence levels were not statistically significantly different for the different section thicknesses (p = 0.28). Increasing the section thickness from 1 to 5 mm decreased image acquisition time from 3 min 54 s to 41 s. CONCLUSIONS: Five-millimeter-section thickness was adequate for identification of 5-12 mm polyps regardless of shape. Pending further reduction in acquisition time, this prototype sequence holds promise for segmental imaging of the colon with MR colonography.