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.

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.

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.

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.

Metastatic Non-Small Cell Lung Cancer Mimicking Metaplastic Breast Cancer: A Case Report.

NGS used to diagnose and treat NSCLC patient with initial concern for metaplastic breast cancer.

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.

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.

Volume progression in polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive enlargement of cyst-filled kidneys. METHODS: In a three-year study, we measured the rates of change in total kidney volume, total cyst volume, and iothalamate clearance in patients with ADPKD. Of a total of 241 patients, in 232 patients without azotemia who were 15 to 46 years old at baseline we used magnetic-resonance imaging to correlate the total kidney volume and total cyst volume with iothalamate clearance. Statistical methods included analysis of variance, Pearson correlation, and multivariate regression analysis. RESULTS: Total kidney volume and total cyst volume increased exponentially, a result consistent with an expansion process dependent on growth. The mean (+/-SD) total kidney volume was 1060+/-642 ml at baseline and increased by a mean of 204+/-246 ml (5.27+/-3.92 percent per year, P<0.001) over a three-year period among 214 patients. Total cyst volume increased by 218+/-263 ml (P<0.001) during the same period among 210 patients. The baseline total kidney volume predicted the subsequent rate of increase in volume, independently of age. A baseline total kidney volume above 1500 ml in 51 patients was associated with a declining glomerular filtration rate (by 4.33+/-8.07 ml per minute per year, P<0.001). Total kidney volume increased more in 135 patients with PKD1 mutations (by 245+/-268 ml) than in 28 patients with PKD2 mutations (by 136+/-100 ml, P=0.03). CONCLUSIONS: Kidney enlargement resulting from the expansion of cysts in patients with ADPKD is continuous and quantifiable and is associated with the decline of renal function. Higher rates of kidney enlargement are associated with a more rapid decrease in renal function.

Acute abdominal pain: value of non-contrast enhanced ultra-low-dose multi-detector row CT as a substitute for abdominal radiographs.

The aim of this study was to evaluate a non-enhanced ultra-low-dose (ULD) abdominal-pelvic multi-detector row computerized tomography (MDCT) to assess patients with acute abdominal pain who would otherwise undergo three-view abdominal X-ray series. Institutional review board approval was obtained with waiver of informed consent. This study was Health Insurance Portability and Accountability Act-compliant. One hundred and sixty-three patients (mean age, 51 years; range, 19-82 years, M/F = 110:53) who underwent ULD MDCT were included in the study. Two subspecialty radiologists independently reviewed the images for abnormal findings and image quality parameters. The effective radiation dose was calculated for each patient and compared to standard-dose computed tomography (CT) scans of 50 matched controls. Findings were confirmed by reviewing the patients' medical records, and statistical analysis was performed. ULD MDCT showed a high sensitivity (100%), specificity (98.5%), and positive predictive value (91.7%) for detection of free air, stones, and intestinal obstruction. For other sources of abdominal pain, the overall sensitivity, specificity, and positive predictive value were 86%, 96%, and 95%, respectively. Mean effective radiation dose from this study was 2.10 mSv (range of 0.67 to 6.64 mSv) with a 78% mean dose reduction compared to standard-dose CT. There was good inter-observer agreement (=0.4 to 0.81). ULD abdominal-pelvic MDCT provides rapid and reasonably accurate diagnostic information in patients with acute abdominal pain at a very low radiation dose.

Contrast-induced nephropathy: contrast material not required?

OBJECTIVE: This commentary deals with the study by Newhouse and colleagues in this issue of the AJR discussing the implications of a lack of a control group in previously published studies on contrast-induced nephropathy (CIN). CONCLUSION: Until more rigorous studies including an appropriate control group address the issue of CIN, our understanding of the actual risk of CIN when administering IV contrast media is limited.

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.

Clinical significance of main pancreatic duct dilation on computed tomography: single and double duct dilation.

AIM: To study the patients with main pancreatic duct dilation on computed tomography (CT) and thereby to provide the predictive criteria to identify patients at high risk of significant diseases, such as pancreatic cancer, and to avoid unnecessary work up for patients at low risk of such diseases. METHODS: Patients with dilation of the main pancreatic duct on CT at Emory University Hospital in 2002 were identified by computer search. Clinical course and ultimate diagnosis were obtained in all the identified patients by abstraction of their computer database records. RESULTS: Seventy-seven patients were identified in this study. Chronic pancreatitis and pancreatic cancer were the most common causes of the main pancreatic duct dilation on CT. Although the majority of patients with isolated dilation of the main pancreatic duct (single duct dilation) had chronic pancreatitis, one-third of patients with single duct dilation but without chronic pancreatitis had pancreatic malignancies, whereas most of patients with concomitant biliary duct dilation (double duct dilation) had pancreatic cancer. CONCLUSION: Patients with pancreatic double duct dilation need extensive work up and careful follow-up since a majority of these patients are ultimately diagnosed with pancreatic cancer. Patients with single duct dilation, especially such patients without any evidence of chronic pancreatitis, also need careful follow-up since the possibility of pancreatic malignancy, including adenocarcinoma and intraductal papillary mucinous tumors, is still high.

Occult spinal dysraphism and urolithiasis: are patients at higher risk of stone disease?

BACKGROUND AND PURPOSE: Spinal dysraphism is associated with urinary-tract dysfunction in severe cases such as meningomyelocele, in part because of incomplete innervation of the lower urinary tract. Patients with meningomyelocele are at higher risk for stone formation, possibly secondary to stasis of urine from aberrant storage and emptying. However, minimal data exist on the risk of stone formation in patients with milder forms of spinal dysraphism. The purpose of this study was to examine whether an association exists between urolithiasis and occult spinal dysraphism (OSD). PATIENTS AND METHODS: All patients who underwent a non-contrast CT scan of the abdomen and pelvis during a 4-month period were included. The final dataset consisted of 374 consecutive patients (195 men, 179 women) with a mean age of 54.2 years (range 18-95 years). Scans were reviewed for evidence of urolithiasis and, independently, for skeletal abnormalities. Patients with urolithiasis included those with a kidney, ureteral, or bladder stone(s). Patients with OSD included those with bifid lumbosacral bony elements, posterior arch defects, or incomplete fusion or non-fusion of S1, S2, or S3. The association between urolithiasis and OSD was examined by calculating series of crude and adjusted odds ratios (ORs) with corresponding 95% confidence intervals (CIs). RESULTS: Of the 374 patients, 135 (36.1%) had urinary calculi, and 83 (22.2%) had OSD. No relation was found between the prevalence of OSD and stone disease (OR 1.22; 95% CI 0.72, 2.08), even after adjusting for potential confounders. CONCLUSION: Unlike severe spinal dysraphism, OSD does not appear to confer an increased risk of stone disease.