Imaging of Vesicoureteral Reflux: AJR Expert Panel Narrative Review.

Vesicoureteral reflux (VUR) is a common congenital anomaly of the urinary tract that can present with collecting system dilation or as a febrile infection. VUR can lead to permanent renal sequela requiring surgery but can also spontaneously resolve without complication. Therefore, it is important to recognize those patient populations who warrant imaging for screening, confirmation, or ongoing surveillance for VUR, while avoiding overdiagnosis. In the appropriate patient populations, an accurate diagnosis of VUR allows early treatment and prevention of pyelonephritis and scarring. Various imaging modalities are available to diagnose and grade VUR, including voiding cystourethrogram (VCUG), radionucleotide cystography (RNC), and contrast-enhanced voiding urosonography (ceVUS). The objective of this article is to summarize the current understanding of VUR diagnosis and management and to discuss these imaging modalities' strengths and pitfalls. Considerations include indications for VUR imaging, patient preparation, conduct of the examination, issues related to radiologic reporting, and cost-effectiveness. An emphasis is placed on ceVUS, which is the most recently introduced of the three imaging modalities and is receiving growing support among pediatric radiologists.

Real-time ultrasound-derived fat fraction in pediatric population: feasibility validation with MR-PDFF.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children. To avoid limitations of liver biopsy and MRI, quantitative ultrasound has become a research focus. Ultrasound-derived fat fraction (UDFF) is based on a combination of backscatter coefficient and attenuation parameter. OBJECTIVE: The objectives of the study were to determine (1) agreement between UDFF/MRI proton density fat fraction (MR-PDFF) and (2) whether BMI and age are predictive for UDFF. MATERIALS AND METHODS: This cross-sectional prospective study included a convenience sample of 46 children referred for clinically indicated abdominal MRI. MR-PDFF and five acquisitions of UDFF were collected. Intraclass correlation coefficient (ICC) and Bland-Altman analysis were used to assess agreement between MR-PDFF and UDFF. Receiver operating characteristic curves were calculated for UDFF prediction of liver steatosis (MR-PDFF ≥ 6%). Multivariable regression was performed to assess BMI and age as predictors for UDFF. RESULTS: Twenty-two participants were male, 24 were female, and the mean age was 14 ± 3 (range: 7-18) years. Thirty-six out of 46 participants had normal liver fat fraction <6%, and 10/46 had liver steatosis. UDFF was positively associated with MR-PDFF (ICC 0.92 (95% CI, 0.89-0.96). The mean bias between UDFF and MR-PDFF was 0.64% (95% LOA, -5.3-6.6%). AUROC of UDFF for steatosis was of 0.95 (95% CI, 0.89-0.99). UDFF cutoff of 6% had a sensitivity of 90% (95% CI, 55-99%) and a specificity of 94% (95% CI, 81-0.99%). BMI was an independent predictor of UDFF (correlation: 0.55 (95% CI, 0.35-0.95)). CONCLUSIONS: UDFF shows strong agreement with MR-PDFF in children. A UDFF cutoff of 6% provides good sensitivity and specificity for detection of MR-PDFF of ≥ 6%.

Gender-based salary differences in academic medicine: a retrospective review of data from six public medical centers in the Western USA.

OBJECTIVES: We assessed the effect of gender, rank and research productivity on compensation for faculty at academic medical centres. DESIGN: A web-based retrospective review of salary for professors in 2016. SETTING: Faculty from six state-run, publicly funded academic medical centres in the Western USA. PARTICIPANTS: 799 faculty members, 225 assistant (51% women), 200 associate (40% women) and 374 full professors (32% women) from general surgery (26% women), obstetrics and gynaecology (70% women) and radiology (34% women). METHODS: Archived online faculty profiles were reviewed for gender, rank and compensation (total, baseline and supplemental). Total compensation was defined as baseline compensation plus supplemental income. Baseline compensation was defined as base salary minus reductions due to participation in the voluntary Employee Reduction in Time and phased retirement programmes. Supplemental income was defined as additional salary for clinical care and research (eg, grants). Elsevier's Scopus was used to collect data on h-index, a measure of research productivity. Linear regression models were estimated to determine the relationship between these factors and salary. RESULTS: Total compensation was significantly higher for men across all professorial ranks in both general surgery [Formula: see text] and obstetrics and gynaecology [Formula: see text]. Women faculty members within these departments earned almost US$75 000 less than their men colleagues. The disparity in salary originates from gaps in supplemental income, as baseline compensation was not significantly different between men and women. No significant gender difference in total compensation for radiology was found [Formula: see text]. Higher h-index was associated with higher baseline compensation across all departments as well as with supplemental income for general surgery. Higher h-index was related to lower supplemental income for radiology and was not related to supplemental income for obstetrics and gynaecology. CONCLUSIONS: Further investigations should focus on discrepancies in supplemental income, which may preferentially benefit men.

Contrast-enhanced US in Pediatric Patients: Overview of Bowel Applications.

Contrast material-enhanced US is a technique that is approved by the U.S. Food and Drug Administration for the characterization of liver lesions and intravesicular applications in children; however, contrast-enhanced US has several other pediatric applications in clinical practice. The most common application is for patients with inflammatory bowel disease (IBD). Contrast-enhanced US can be used to diagnose IBD, distinguish regions of active or chronic inflammation of the bowel wall, and evaluate associated complications such as abscesses, fistulas, and strictures. Dynamic contrast material evaluation provides qualitative and quantitative information about mural and mesenteric blood flow, which is essential in the determination of disease activity in these patients. It also has the potential to provide a means of monitoring the response to therapy beyond endoscopy or MR enterography. In addition to its use for IBD, contrast-enhanced US can be used to assess for bowel perfusion when problem solving in patients with necrotizing enterocolitis, neonatal bowel infarction, or intussusception. It is a useful imaging technique to fortify diagnoses that may otherwise be indeterminate, such as appendicitis, epiploic appendagitis, intraluminal bowel masses, and complex cysts. Finally, innovative applications such as shear-wave elastography have the potential to provide information about the stiffness of the bowel wall. Online supplemental material is available for this article. ©RSNA, 2020 See discussion on this article by Watson and Humphries.

The role of imaging in the management of necrotising enterocolitis: a multispecialist survey and a review of the literature.

OBJECTIVES: To investigate current practices and perceptions of imaging in necrotising enterocolitis (NEC) according to involved specialists, put them in the context of current literature, and identify needs for further investigation. METHODS: Two hundred two neonatologists, paediatric surgeons, and radiologists answered a web-based questionnaire about imaging in NEC at their hospitals. The results were descriptively analysed, using proportion estimates with 95% confidence intervals. RESULTS: There was over 90% agreement on the value of imaging for confirmation of the diagnosis, surveillance, and guidance in decisions on surgery as well as on abdominal radiography as the first-choice modality and the most important radiographic signs. More variation was observed regarding some indications for surgery and the use of some ultrasonographic signs. Fifty-eight per cent stated that ultrasound was used for NEC at their hospital. Examination frequency, often once daily or more but with considerable variations, and projections used in AR were usually decided individually rather than according to fixed schedules. Predicting the need of surgery was regarded more important than formal staging. CONCLUSION: Despite great agreement on the purposes of imaging in NEC and the most important radiographic signs of the disease, there was considerable diversity in routines, especially regarding examination frequency and the use of ultrasound. Apart from continuing validation of ultrasound, important objectives for future studies include definition of the supplementary roles of both imaging modalities in relation to other diagnostic parameters and evaluation of various imaging routines in relation to timing of surgery, complications, and mortality rate. KEY POINTS: • Imaging is an indispensable tool in the management of necrotising enterocolitis • Predicting the need of surgery is regarded more important than formal staging • There is great consensus on important signs of NEC on abdominal radiography • There is more uncertainty regarding the role of ultrasound • Individualised management is preferred over standardised diagnostic algorithms.

Prediction of neonatal respiratory distress in pregnancies complicated by fetal lung masses.

OBJECTIVE: The objective of this article is to evaluate the utility of fetal lung mass imaging for predicting neonatal respiratory distress. METHOD: Pregnancies with fetal lung masses between 2009 and 2014 at a single center were analyzed. Neonatal respiratory distress was defined as intubation and mechanical ventilation at birth, surgery before discharge, or extracorporeal membrane oxygenation (ECMO). The predictive utility of the initial as well as maximal lung mass volume and congenital pulmonary airway malformation volume ratio by ultrasound (US) and magnetic resonance imaging (MRI) was analyzed. RESULTS: Forty-seven fetal lung mass cases were included; of those, eight (17%) had respiratory distress. The initial US was performed at similar gestational ages in pregnancies with and without respiratory distress (26.4 ± 5.6 vs 22.3 ± 3 weeks, p = 0.09); however, those with respiratory distress had higher congenital volume ratio at that time (1.0 vs 0.3, p = 0.01). The strongest predictors of respiratory distress were maximal volume >24.0 cm3 by MRI (100% sensitivity, 91% specificity, 60% positive predictive value, and 100% negative predictive value) and maximal volume >34.0 cm3 by US (100% sensitivity, 85% specificity, 54% positive predictive value, and 100% negative predictive value). CONCLUSION: Ultrasound and MRI parameters can predict neonatal respiratory distress, even when obtained before 24 weeks. Third trimester parameters demonstrated the best positive predictive value. © 2017 John Wiley & Sons, Ltd.

Fetal suprarenal masses--assessing the complementary role of magnetic resonance and ultrasound for diagnosis.

OBJECTIVE: To assess the value and complementary roles of fetal MRI and US for characterization and diagnosis of suprarenal masses. MATERIALS AND METHODS: We conducted a multi-institutional retrospective database search for prenatally diagnosed suprarenal masses between 1999 and 2012 and evaluated the roles of prenatal US and fetal MRI for characterization and diagnosis, using postnatal diagnosis or surgical pathology as the reference standard. Prenatal US and fetal MRI were assessed for unique findings of each modality. RESULTS: The database yielded 25 fetuses (gestational age 20-37 weeks) with suprarenal masses. Twenty-one fetuses had prenatal US, 22 had MRI, 17 had both. Postnatal diagnoses included nine subdiaphragmatic extralobar sequestrations, seven adrenal hemorrhages, five neuroblastomas (four metastatic), two lymphatic malformations, one duplex kidney with upper pole cystic dysplasia, and one adrenal hyperplasia. Ultrasound was concordant with MRI for diagnoses in 12/17 (70.6%) cases. Discordant diagnoses between US and MRI included three neuroblastomas and two adrenal hemorrhages. In the three neuroblastomas US was equivocal and MRI was definitive for neuroblastoma, demonstrating heterogeneous, intermediate-signal solid masses and liver metastases. In the two cases of adrenal hemorrhage US was equivocal and MRI was definitive with signal characteristics of hemorrhage. In 2/4 neuroblastomas, Doppler US demonstrated a systemic artery suggesting extralobar sequestration; however MRI signal characteristics correctly diagnosed neuroblastoma. All cases of extralobar sequestration were correctly diagnosed by US and MRI. CONCLUSION: US and MRI both accurately detect suprarenal masses. MRI complements US in equivocal diagnoses and detects additional findings such as liver metastases in neuroblastoma.

Effectiveness of a staged US and CT protocol for the diagnosis of pediatric appendicitis: reducing radiation exposure in the age of ALARA.

PURPOSE: To evaluate the effectiveness of a staged ultrasonography (US) and computed tomography (CT) imaging protocol for the accurate diagnosis of suspected appendicitis in children and the opportunity for reducing the number of CT examinations and associated radiation exposure. MATERIALS AND METHODS: This retrospective study was compliant with HIPAA, and a waiver of informed consent was approved by the institutional review board. This study is a review of all imaging studies obtained in children suspected of having appendicitis between 2003 and 2008 at a suburban pediatric emergency department. A multidisciplinary staged US and CT imaging protocol for the diagnosis of appendicitis was implemented in 2003. In the staged protocol, US was performed first in patients suspected of having appendicitis; follow-up CT was recommended when US findings were equivocal. Of 1228 pediatric patients who presented to the emergency department for suspected appendicitis, 631 (287 boys, 344 girls; age range, 2 months to 18 years; median age, 10 years) were compliant with the imaging pathway. The sensitivity, specificity, negative appendectomy rate (number of appendectomies with normal pathologic findings divided by the number of surgeries performed for suspected appendicitis), missed appendicitis rate, and number of CT examinations avoided by using the staged protocol were analyzed. RESULTS: The sensitivity and specificity of the staged protocol were 98.6% and 90.6%, respectively. The negative appendectomy rate was 8.1% (19 of 235 patients), and the missed appendicitis rate was less than 0.5% (one of 631 patients). CT was avoided in 333 of the 631 patients (53%) in whom the protocol was followed and in whom the US findings were definitive. CONCLUSION: A staged US and CT imaging protocol in which US is performed first in children suspected of having acute appendicitis is highly accurate and offers the opportunity to substantially reduce radiation.

A continuous heparin infusion does not prevent catheter-related thrombosis in infants after cardiac surgery.

OBJECTIVE: To determine whether a continuous infusion of heparin reduces the rate of catheter-related thrombosis in neonates and infants post cardiac surgery. Central venous and intracardiac catheters are used routinely in postoperative pediatric cardiac patients. Catheter-related thrombosis occurs in 8% to 45% of pediatric patients with central venous catheters. DESIGN: Single-center, randomized, placebo-controlled, double-blinded trial. SETTING: Cardiovascular intensive care unit, university-affiliated children's hospital. PATIENTS: Children <1 yr of age recovering from cardiac surgery. INTERVENTIONS: Patients were randomized to receive either continuous heparin at 10 units/kg/hr or placebo. The primary end point was catheter-related thrombosis as assessed by serial ultrasonography. RESULTS: Study enrollment was discontinued early based on results from an interim futility analysis. Ninety subjects were enrolled and received the study drug (heparin, 53; placebo, 37). The catheter-related thrombosis rate in the heparin group, compared with the placebo group, was 15% vs. 16% (p = .89). Subjects in the heparin group had a higher mean partial thromboplastin time (52 secs vs. 42 secs, p = .001), and this difference was greater for those aged <30 days (64 secs vs. 43 secs, p = .008). Catheters in place > or = 7 days had both a greater risk of thrombus formation (odds ratio, 4.3; p = .02) and catheter malfunction (odds ratio, 11.2; p = .008). We observed no significant differences in other outcome measures or in the frequency of adverse events. CONCLUSIONS: A continuous infusion of heparin at 10 units/kg/hr was safe but did not reduce catheter-related thrombus formation. Heparin at this dose caused an increase in partial thromboplastin time values, which, unexpectedly, was more pronounced in neonates.

Accuracy of MDCT in predicting site of gastrointestinal tract perforation.

OBJECTIVE: The purpose of this study was to prospectively evaluate the accuracy of MDCT for preoperative determination of the site of surgically proven gastrointestinal tract perforations and to determine the most predictive findings in this diagnosis. SUBJECTS AND METHODS: We prospectively studied 85 consecutive patients with extraluminal air on MDCT who had surgically proven gastrointestinal tract perforations. All patients underwent surgery within 12 hours after MDCT was performed. Two experienced radiologists, blinded to the surgical diagnosis, reached a consensus prediction of the site of the perforation using the following eight MDCT findings: concentration of extraluminal air bubbles adjacent to the bowel wall, free air in supramesocolic or inframesocolic compartments, extraluminal air in both abdomen and pelvis, focal defect in the bowel wall, segmental bowel-wall thickening, perivisceral fat stranding, abscess, and extraluminal fluid. MDCT imaging results were compared with surgical and pathologic findings. Logistic regression analyses were performed to assess the significance of the different radiologic criteria. RESULTS: Analysis of MDCT images was predictive of the site of gastrointestinal tract perforation in 73 (86%) of 85 patients. Logistic regression showed that concentration of extraluminal air bubbles (p < 0.001), segmental bowel wall thickening (p < 0.001), and focal defect of the bowel wall (p = 0.007) were strong predictors of the site of bowel perforation. CONCLUSION: MDCT is highly accurate for predicting the site of gastrointestinal tract perforations. Three of eight CT findings significantly correlate with surgical diagnosis.

Quantitative diffusion imaging in breast cancer: a clinical prospective study.

PURPOSE: To study the correlation between apparent diffusion coefficient (ADC) and pathology in patients with undefined breast lesion, to validate how accurately ADC is related to histology, and to define a threshold value of ADC to distinguish malignant from benign lesions. MATERIALS AND METHODS: Seventy-eight patients (110 lesions) were referred for positive or dubious findings. Three-dimensional fast low-angle shot (3D-FLASH) with contrast injection was applied. EPI diffusion-weighted imaging (DWI) with fat saturation was performed, and ROIs were selected on subtraction 3D-FLASH images before and after contrast injection, and copied on an ADC map. Inter- and intraobserver analyses were performed. RESULTS: At pathology 22 lesions were benign, 65 were malignant, and 23 were excluded. The ADCs of malignant and benign lesions were statistically different. In malignant tumors the ADC was (mean +/- SEM) 0.95 +/- 0.027 x 10(-3)mm(2)/second, and in benign tumors it was 1.51 +/- 0.068 x 10(-3)mm(2)/second. According to receiver operating characteristic (ROC) curves, we found a threshold between malignant and benign lesions for highest sensitivity and specificity (both 86%) around 1.13 +/- 0.10 x 10(-3)mm(2)/second. For a threshold of 0.95 +/- 0.10 x 10(-3)mm(2)/second, specificity was 100% but sensitivity was very low. Inter- and intraobserver studies showed good reproducibility. CONCLUSION: The ADC may help to differentiate benign and malignant lesions with good specificity, and may increase the overall specificity of breast MRI.

Intragastric band erosion after laparoscopic adjustable gastric banding for morbid obesity: imaging characteristics of an underreported complication.

OBJECTIVE: Our purpose was to describe the imaging findings of intragastric band erosion, an underreported complication after laparoscopic adjustable gastric banding for the treatment of morbid obesity. In this long-term complication, the gastric band fastened around the upper stomach to create a small proximal gastric pouch gradually erodes into the stomach wall and can extend into the gastric lumen. We present three cases of patients with band erosion in whom findings on an upper gastrointestinal series and CT established the diagnosis. CONCLUSION: Diagnosis of intragastric band erosion after gastric banding is usually made with endoscopy. However, the radiologic appearance of band erosion when visualized on an upper gastrointestinal series is pathognomonic and allows initial imaging diagnosis. In patients with extraluminal air or prosthesis infection, CT findings also are suggestive of this postoperative complication.