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.

Multiinstitutional Evaluation of the Liver Surface Nodularity Score on CT for Staging Liver Fibrosis and Predicting Liver-Related Events in Patients With Hepatitis C.

BACKGROUND. In single-institution multireader studies, the liver surface nodularity (LSN) score accurately detects advanced liver fibrosis and cirrhosis and predicts liver decompensation in patients with chronic liver disease (CLD) from hepatitis C virus (HCV). OBJECTIVE. The purpose of this study was to assess the diagnostic performance of the LSN score alone and in combination with the (FIB-4; fibrosis index based on four factors) to detect advanced fibrosis and cirrhosis and to predict future liver-related events in a multiinstitutional cohort of patients with CLD from HCV. METHODS. This retrospective study included 40 consecutive patients, from each of five academic medical centers, with CLD from HCV who underwent nontargeted liver biopsy within 6 months before or after abdominal CT. Clinical data were recorded in a secure web-based database. A single central reader measured LSN scores using software. Diagnostic performance for detecting liver fibrosis stage was determined. Multivariable models were constructed to predict baseline liver decompensation and future liver-related events. RESULTS. After exclusions, the study included 191 patients (67 women, 124 men; mean age, 54 years) with fibrosis stages of F0-F1 (n = 37), F2 (n = 44), F3 (n = 46), and F4 (n = 64). Mean LSN score increased with higher stages (F0-F1, 2.26 ± 0.44; F2, 2.35 ± 0.37; F3, 2.42 ± 0.38; F4, 3.19 ± 0.89; p < .001). The AUC of LSN score alone was 0.87 for detecting advanced fibrosis (≥ F3) and 0.89 for detecting cirrhosis (F4), increasing to 0.92 and 0.94, respectively, when combined with FIB-4 scores (both p = .005). Combined scores at optimal cutoff points yielded sensitivity of 75% and specificity of 82% for advanced fibrosis, and sensitivity of 84% and specificity of 85% for cirrhosis. In multivariable models, LSN score was the strongest predictor of baseline liver decompensation (odds ratio, 14.28 per 1-unit increase; p < .001) and future liver-related events (hazard ratio, 2.87 per 1-unit increase; p = .03). CONCLUSION. In a multiinstitutional cohort of patients with CLD from HCV, LSN score alone and in combination with FIB-4 score exhibited strong diagnostic performance in detecting advanced fibrosis and cirrhosis. LSN score also predicted future liver-related events. CLINICAL IMPACT. The LSN score warrants a role in clinical practice as a quantitative marker for detecting advanced liver fibrosis, compensated cirrhosis, and decompensated cirrhosis and for predicting future liver-related events in patients with CLD from HCV.

Focal Nodular Hyperplasia and Focal Nodular Hyperplasia-like Lesions.

Focal nodular hyperplasia (FNH) is a benign lesion occurring in a background of normal liver. FNH is seen most commonly in young women and can often be accurately diagnosed at imaging, including CT, MRI, or contrast-enhanced US. In the normal liver, FNH frequently must be differentiated from hepatocellular adenoma, which although benign, is managed differently because of the risks of hemorrhage and malignant transformation. When lesions that are histologically identical to FNH occur in a background of abnormal liver, they are termed FNH-like lesions. These lesions can be a source of diagnostic confusion and must be differentiated from malignancies. Radiologists' familiarity with the imaging appearance of FNH-like lesions and knowledge of the conditions that predispose a patient to their formation are critical to minimizing the risks of unnecessary intervention for these lesions, which are rarely symptomatic and carry no risk for malignant transformation. FNH is thought to form secondary to an underlying vascular disturbance, a theory supported by the predilection for formation of FNH-like lesions in patients with a variety of hepatic vascular abnormalities. These include abnormalities of hepatic outflow such as Budd-Chiari syndrome, abnormalities of hepatic inflow such as congenital absence of the portal vein, and hepatic microvascular disturbances, such as those that occur after exposure to certain chemotherapeutic agents. Familiarity with the imaging appearances of these varied conditions and knowledge of their association with formation of FNH-like lesions allow radiologists to identify with confidence these benign lesions that require no intervention. Online supplemental material is available for this article. ©RSNA, 2022.

Active Surveillance Versus Nephron-Sparing Surgery for a Bosniak IIF or III Renal Cyst: A Cost-Effectiveness Analysis.

OBJECTIVE: The objective of our study was to evaluate the cost-effectiveness of active surveillance (AS) versus nephron-sparing surgery (NSS) in patients with a Bosniak IIF or III renal cyst. MATERIALS AND METHODS: Markov models were developed to estimate life expectancy and lifetime costs for 60-year-old patients with a Bosniak IIF or III renal cyst (the reference cases) managed by AS versus NSS. The models incorporated the malignancy rates, reclassification rates during follow-up, treatment effectiveness, complications and costs, and short- and long-term outcomes. An incremental cost-effectiveness analysis was performed to identify management preference under an assumed $75,000 per quality-adjusted life-year (QALY) societal willingness-to-pay threshold, using data from studies in the literature and the 2015 Medicare Physician Fee Schedule. The effects of key parameters were addressed in a multiway sensitivity analysis. RESULTS: The prevalence of malignancy for Bosniak IIF and III renal cysts was 26% (25/96) and 52% (542/1046). Under base case assumptions for Bosniak IIF cysts, the incremental cost-effectiveness ratio of NSS relative to AS was $731,309 per QALY for women, exceeding the assumed societal willingness-to-pay threshold, and AS outperformed NSS for both life expectancy and cost for men. For Bosniak III cysts, AS yielded greater life expectancy (24.8 and 19.4 more days) and lower lifetime costs (cost difference of $12,128 and $11,901) than NSS for men and women, indicating dominance of AS over NSS. Superiority of AS held true in sensitivity analyses for men 46 years old or older and women 57 years old or older even when all parameters were set to favor NSS. CONCLUSION: AS is more cost-effective than NSS for patients with a Bosniak IIF or III renal cyst.

Intubation Performance of Advanced Airway Devices in a Helicopter Emergency Medical Service Setting.

OBJECTIVE: This study attempts to determine if newer indirect laryngoscopes or intubating devices are superior to a standard laryngoscope for intubation success among helicopter emergency medical service (HEMS) personnel. METHODS: Flight nurses and paramedics intubated standardized mannequins with a normal airway, a trauma airway, and a difficult airway using a standard laryngoscope, a gum elastic bougie, the Airtraq laryngoscope (King System Corp, Noblesville, IN), the Glidescope Ranger laryngoscope (Verathon Inc, Bothell, WA), and the S.A.L.T. device (Microtek Medical, Inc, Lehmberg, IN) in grounded helicopters wearing helmets and flight gear. Participant demographics, time to glottic view, the modified Cormack-Lehane score, total intubation time, number of attempts, and overall successful intubation were recorded for each type of airway. RESULTS: Two-hundred thirty-six subjects were initially enrolled across 107 bases in 15 states, and 177 completed the study. First-attempt success rates did not vary by device for the normal airway (P = .203), but the Airtraq laryngoscope and the S.A.L.T. device were highest in the difficult airway (82.0% and 85.0%, respectively; P < .0001). The time to first-attempt success in the difficult airway was lowest for the S.A.L.T. device and the Airtraq laryngoscope (mean = 9.72 seconds and 19.70 seconds, respectively; P < .0001). CONCLUSION: Using HEMS providers, the Airtraq laryngoscope and the S.A.L.T. device showed the fastest and highest intubation success on the first attempt in difficult simulated HEMS airway scenarios.

Gadobenate Dimeglumine Administration and Nephrogenic Systemic Fibrosis: Is There a Real Risk in Patients with Impaired Renal Function?

PURPOSE: To determine the incidence of nephrogenic systemic fibrosis (NSF) in patients with renal disease who received gadobenate dimeglumine at a single medical center. MATERIALS AND METHODS: This was an institutional review board-approved HIPAA-compliant retrospective study with waiver of informed consent. Patients either underwent dialysis or not, had an abnormal estimated glomerular filtration rate (eGFR), and underwent magnetic resonance (MR) imaging and/or MR angiography with gabobenate dimeglumine in 2010. Dialysis status, eGFR, time to transplantation, waiting list status, contrast material volume at index imaging, and additional imaging examinations between 2007 and 2014 were recorded. Clinical notes with and without integument examinations, pathologic records, and additional patient communication were evaluated for development of NSF through September 2014. Dates of latest documented integument examination and latest interaction were recorded. Mean, standard deviation, and median values were obtained, along with incidence percentage of NSF. RESULTS: Of 401 patients (172 women, 229 men; mean age, 50 years), 75.5% were dialysis dependent (n = 303) and 24.4% (n = 98) were not undergoing dialysis, with a mean eGFR ± standard deviation of 17 mL/min per 1.73 m(2) ± 5.6 (range, 6-41 mL/min per 1.73 m(2); median, 16.3 mL/min per 1.73 m(2)). Mean and median contrast material volume at index imaging were 24 mL ± 5.7 (range, 9-45 mL). Additional contrast material volume administered was 23 mL ± 12.9 (range, 6-64 mL; median, 20 mL; n = 66). One hundred twenty-six patients (31%) received a transplant; mean time to transplantation was 1.72 years ± 1.25 (range, 0-4.46 years; median, 1.4 years). No patients received diagnoses of NSF. Mean follow-up was 2.35 years ± 1.61 (range, 0.00-4.61 years; median, 2.75 years) with documented integument examination and 3.08 years ± 1.36 (range, 0.16-4.66 years; median, 3.66 years) with direct patient communication. CONCLUSION: No patients undergoing peritoneal dialysis, hemodialysis, or nondialysis who experienced renal failure developed NSF after administration of gadobenate dimeglumine after more than 2 years' mean follow-up. Gadobenate dimeglumine may be safe in this population.

Two hundred sixty pediatric emergency airway encounters by air transport personnel: a report of the air transport emergency airway management (NEAR VI: "A-TEAM") project.

BACKGROUND: Effective airway management is the cornerstone of resuscitative efforts for any critically ill or injured patient. The role and safety of pediatric prehospital intubation is controversial, particularly after prior research has shown varying degrees of intubation success. We report a series of consecutive prehospital pediatric intubations performed by air-transport providers. METHODS: We retrospectively reviewed intubation flight records from an 89-rotorcraft, multistate emergency flight service during the time period from January 1, 2007, to December 31, 2009. All patients younger than 15 years were included in our analysis. We characterized patient, flight, and operator demographics; intubation methods; success rates; rescue techniques; and adverse events with descriptive statistics. We report proportions with 95% confidence intervals and differences between groups with Fisher exact and χ tests; P < 0.05 was considered significant. RESULTS: Two hundred sixty pediatric intubations were performed consisting of 88 medical (33.8%) and 172 trauma (66.2%) cases; 98.8% (n = 257) underwent an orotracheal intubation attempt as the first method. First-pass intubation success was 78.6% (n = 202), and intubation was ultimately successful in 95.7% (n = 246) of cases. Medical and trauma intubations had similar success rates (98% vs 95%, Fisher exact test P = 0.3412). There was no difference in intubation success between age groups (χ = 0.26, P = 0.88). Three patients were managed primarily with an extraglottic device. Rescue techniques were used in 11 encounters (4.2%), all of which were successful. Cricothyrotomy was performed twice, both successful. CONCLUSIONS: Prehospital pediatric intubation performed by air-transport providers, using rapid sequence intubation protocols, is highly successful. This effect on patient outcome requires further study.

Bosniak category IIF and III cystic renal lesions: outcomes and associations.

PURPOSE: To evaluate clinical outcomes, pathologic subtypes, metastatic disease rate, and clinical features associated with malignancy in Bosniak category IIF and III cystic renal lesions. MATERIALS AND METHODS: This retrospective study was institutional review board approved and HIPAA compliant. Informed consent was waived. Radiology and hospital information systems were searched for Bosniak IIF and Bosniak III lesions in computed tomographic (CT) reports from January 1, 1994 to August 31, 2009. Patients 18 years and older with unenhanced and contrast material-enhanced CT results and with lesions either surgically resected or with 1 year or more of surveillance were included. Data recorded were history of renal cell carcinoma, number of renal lesions, presence of a coexistent solid renal mass, surgical pathologic findings, and presence of metastatic disease from a renal malignancy. Sixty-two patients with 69 Bosniak IIF lesions and 131 patients with 144 Bosniak III lesions were identified. Proportions from independent groups were compared by using the Fisher exact test; continuous variables were compared by using a two-tailed two-sample t test or a Wilcoxon two-sample test. RESULTS: The malignancy rate of resected Bosniak IIF lesions was 25% (four of 16) and that for Bosniak III lesions was 54% (58 of 107) (P = .03). Thirteen percent (nine of 69) of Bosniak IIF lesions progressed at follow-up, and 50% (four of eight) of these resected cysts were malignant. History of primary renal malignancy, coexisting Bosniak category IV lesion and/or solid renal mass, and multiplicity of Bosniak III lesions were each associated with an increased malignancy rate in Bosniak III lesions. No patients developed locally advanced or metastatic disease from a Bosniak IIF or III lesion. CONCLUSION: Although the malignancy rate in surgically excised Bosniak IIF and Bosniak III cystic renal lesions was 25% and 54%, respectively, in our study, the malignancy rate was higher in patients with a history of primary renal malignancy or coexisting Bosniak IV lesion and/or solid renal neoplasm.

Impact of Maternal Hyperoxygenation on Myocardial Deformation and Loading Conditions in Fetuses with and without Left Heart Hypoplasia.

BACKGROUND: Maternal hyperoxygenation (MHO) is used in a variety of clinical applications, but its impact on fetal cardiovascular physiology is poorly understood. Our aims were to describe the effects of MHO on myocardial deformation parameters and on ultrasound-based metrics of preload and afterload and to assess the differential effect of MHO on fetuses with left heart hypoplasia (LHH). We hypothesized that the effects of MHO would be modulated by loading conditions and that fetuses with LHH would be more sensitive to changes in preload and afterload induced by MHO. METHODS: We performed a post hoc analysis of 36 fetal echocardiograms performed as part of a pilot study of MHO in LHH (n = 9) and control (n = 9) fetuses. Oxygen was administered via 8 L face mask for 10 minutes. Right ventricular (RV) and left ventricular (LV) longitudinal strain and strain rate, estimated aortic and pulmonary cardiac output, pulmonary vein velocity-time integral (VTI) and pulsatility indices (PI) of the middle cerebral artery (MCA), pulmonary arteries (PA), and umbilical artery (UA) were measured at three time points: baseline, during MHO, and 10 minutes after removal of MHO. RESULTS: Maternal hyperoxygenation induced decreases in LV strain and strain rate and increases in RV strain and strain rate. Pulmonary artery PI decreased and pulmonary vein VTI increased, suggesting decreased pulmonary vascular resistance and increased pulmonary venous return. Most findings did not return to baseline after removal of MHO. We found no significant effect of MHO on MCA or UA PI. Left heart hypoplasia cases demonstrated similar effects of MHO in control cases, with larger changes in pulmonary vein VTI and LV strain rate. CONCLUSION: The effects of MHO on LV and RV mechanics suggest that changes in deformation indices may be explained by increases in LV preload and decreases in RV afterload. The time period for recovery of fetal hemodynamics from MHO is ill-defined.

Comparative Effectiveness of Tumor Response Assessment Methods: Standard of Care Versus Computer-Assisted Response Evaluation.

PURPOSE: To compare the effectiveness of metastatic tumor response evaluation with computed tomography using computer-assisted versus manual methods. MATERIALS AND METHODS: In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study, 11 readers from 10 different institutions independently categorized tumor response according to three different therapeutic response criteria by using paired baseline and initial post-therapy computed tomography studies from 20 randomly selected patients with metastatic renal cell carcinoma who were treated with sunitinib as part of a completed phase III multi-institutional study. Images were evaluated with a manual tumor response evaluation method (standard of care) and with computer-assisted response evaluation (CARE) that included stepwise guidance, interactive error identification and correction methods, automated tumor metric extraction, calculations, response categorization, and data and image archiving. A crossover design, patient randomization, and 2-week washout period were used to reduce recall bias. Comparative effectiveness metrics included error rate and mean patient evaluation time. RESULTS: The standard-of-care method, on average, was associated with one or more errors in 30.5% (6.1 of 20) of patients, whereas CARE had a 0.0% (0.0 of 20) error rate ( P < .001). The most common errors were related to data transfer and arithmetic calculation. In patients with errors, the median number of error types was 1 (range, 1 to 3). Mean patient evaluation time with CARE was twice as fast as the standard-of-care method (6.4 minutes v 13.1 minutes; P < .001). CONCLUSION: CARE reduced errors and time of evaluation, which indicated better overall effectiveness than manual tumor response evaluation methods that are the current standard of care.

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.