Refining sonographic criteria for paediatric appendicitis: combined effects of age-based appendiceal size and secondary findings.

OBJECTIVE: Appendiceal diameter is a primary sonographic determinant of paediatric appendicitis. We sought to determine if the diagnostic performance of outer appendiceal diameter differs based on age or with the addition of secondary sonographic findings. METHODS: We retrospectively reviewed patients aged less than 19 years who presented to the Boston Children's Hospital ED and had an ultrasound (US) for the evaluation of appendicitis between November 2015 and October 2018. Our primary outcome was the presence of appendicitis. We analysed the cases to evaluate the optimal outer appendiceal diameter as a predictor for appendicitis stratified by age (<6, 6 to <11, 11 to <19 years), and with the addition of one or more secondary sonographic findings. RESULTS: Overall, 945 patients met criteria for inclusion, of which 43.9% had appendicitis. Overall, appendiceal diameter as a continuous measure demonstrated excellent test performance across all age groups (area under the curve (AUC) >0.95) but was most predictive of appendicitis in the youngest age group (AUC=0.99 (0.98-1.00)). Although there was no significant difference in optimal diameter threshold between age groups, both 7- and 8-mm thresholds were more predictive than 6 mm across all groups (p<0.001). The addition of individual (particularly appendicolith or echogenic fat) or combinations of secondary sonographic findings increased the diagnostic value for appendicitis above diameter alone. CONCLUSIONS: Appendiceal diameter as a continuous measure was more predictive of appendicitis in the youngest group. Across all age groups, the optimal diameter threshold was 7 mm for the diagnosis of paediatric appendicitis. The addition of individual or combination secondary sonographic findings increases diagnostic performance.

Leveraging the Combined Predictive Value of Ultrasound and Laboratory Data to Reduce Radiation Exposure and Resource Utilization in Children with Suspected Appendicitis.

BACKGROUND: Previous investigation has shown that the combined predictive value of white blood cell count and ultrasound (US) findings to be superior to either alone in children with suspected appendicitis. The purpose of this study was to evaluate the impact of a diagnostic clinical pathway (DCP) leveraging the combined predictive value of these tests on computed tomography (CT) utilization and resource utilization. METHODS: Retrospective cohort study comparing 8 mo of data before DCP implementation to 18 mo of data following implementation. The pathway incorporated decision-support for disposition (operative intervention, observation, or further cross-sectional imaging) based on the combined predictive value of laboratory and US data (stratifying patients into low, moderate, and high-risk groups). Study measures included CT and magnetic resonance imaging utilization, imaging-related cost, time to appendectomy, and negative appendectomy rate. RESULTS: Ninety-seven patients in the preintervention period were compared with 319 patients in the postintervention period. Following DCP implementation, CT utilization decreased by 86% (21% versus 3%, P < 0.001). Mean time to appendectomy decreased from 8.5 to 7.2 h (P < 0.001), and the negative appendectomy rate remained unchanged (5% versus 4%, P = 0.54). Magnetic resonance imaging utilization increased following pathway implementation (1% versus 7%, P = 0.02); however, median imaging-related cost was significantly lower in the postimplementation period ($283/case to $270/case, P = 0.002) CONCLUSIONS: In children with suspected appendicitis, implementation of a DCP leveraging the combined predictive value of white blood cell and US data was associated with a reduction in CT utilization, time to appendectomy, and imaging-related cost.

Ultrasound Assessment of Quadriceps Femoris Muscle Thickness in Critically Ill Children.

OBJECTIVES: Evaluate the reliability of ultrasound to measure quadriceps femoris muscle thickness in critically ill children and to describe serial changes in quadriceps femoris muscle thickness in relation to fluid balance and nutritional intake. DESIGN: Prospective observational study. SETTING: Tertiary care children's hospital. PATIENTS: Inpatients age 3 months to 18 years recently admitted to the ICU who were sedated and mechanically ventilated at the time of the first ultrasound scan. METHODS: Prospective observational study to examine the reliability of averaged ultrasound measurements of quadriceps femoris muscle thickness. Change in average quadriceps femoris muscle thickness over time was correlated with fluid balance and nutritional intake. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Averaged quadriceps femoris muscle thickness demonstrated good to excellent reliability when comparing pediatric critical care providers to pediatric radiologists and when comparing between different pediatric critical care providers. We found no significant association between fluid balance over 1 or 3 days and change in quadriceps femoris muscle thickness over the same time frame. However, there was a significant association between percent of goal calories (p < 0.001) or percent of goal protein (p < 0.001) over 6 days and change in quadriceps femoris muscle thickness over the same time frame. CONCLUSIONS: Averaged ultrasound measurements of quadriceps femoris muscle thickness demonstrate good to excellent reliability, are not confounded by fluid balance, and are useful for tracking changes in muscle thickness that are associated with nutritional intake. Ultrasound-based assessment of quadriceps femoris is a clinically useful tool for evaluating muscle mass and may be a proxy for nutritional status.

Does age affect the test performance of secondary sonographic findings for pediatric appendicitis?

BACKGROUND: Secondary sonographic findings of appendicitis can aid image analysis and support diagnosis with and without visualization of an appendix. OBJECTIVE: We sought to determine if age affected the test performance of secondary findings for pediatric appendicitis. MATERIALS AND METHODS: We performed a medical record review of emergency department patients younger than 19 years of age who had a sonogram for suspected appendicitis. Our primary patient outcome was appendicitis, as determined by pathology or by image-confirmed perforation/abscess. Our primary analysis was test performance of secondary sonographic findings as recorded by sonographers on the final diagnosis of appendicitis stratified by age (<6 years, 6 to <11 years, 11 to <19 years). RESULTS: A total of 1,219 patients with suspected appendicitis were evaluated by ultrasound, and 1,147 patients met the criteria for analysis. Of the 1,147 patients, 431 (37.6%) had a final diagnosis of appendicitis. Across all age groups, echogenic fat was the most accurate secondary finding (92.5% [95% confidence interval (CI): 91.0, 94.0]) and free fluid was the least accurate secondary finding (54.7% [95% CI: 51.8, 57.5]). There was no significant difference in the age-stratified test performance of secondary sonographic findings except that (1) appendicolith was a more accurate predictor in patients <6 years old than in the middle group (P<0.001) or the oldest group (P<0.001), and (2) free fluid was a more accurate predictor in the middle group than in the oldest group (P=0.02). CONCLUSION: There are no significant differences in the age-stratified test performance of secondary sonographic findings in the prediction of pediatric appendicitis except that appendicolith is more predictive in younger patients.

Contrast-enhanced ultrasound of pediatric lungs.

In addition to radiography, ultrasound (US) has long proved to be a valuable imaging modality to evaluate the pediatric lung and pleural cavity. Its many inherent advantages, including real-time performance, high spatial resolution, lack of ionizing radiation and lack of need for sedation make it preferable over other imaging modalities such as CT. Since the introduction of ultrasound contrast agents (UCAs), contrast-enhanced ultrasound (CEUS) has become a valuable complementary US technique, with many well-established uses in adults and evolving uses in children. Lung CEUS applications are still not licensed and are performed off-label, although the added value of CEUS in certain clinical scenarios is increasingly reported. The limited evidence of CEUS in the evaluation of pediatric lungs focuses primarily on community-acquired pneumonia and its complications. In this clinical setting, CEUS is used to confidently and accurately diagnose necrotizing pneumonia and to delineate pleural effusions and empyema. In addition to intravenous use, UCAs can be administered directly into the pleural cavity through chest catheters to improve visualization of loculations within a complex pleural effusion, which might necessitate fibrinolytic therapy. The purpose of this paper is to present the current experience on pediatric lung CEUS and to suggest potential additional uses that can be derived from adult studies.

Contrast-enhanced ultrasound of the pediatric brain.

Brain contrast-enhanced ultrasound (CEUS) is an emerging application that can complement gray-scale US and yield additional insights into cerebral flow dynamics. CEUS uses intravenous injection of ultrasound contrast agents (UCAs) to highlight tissue perfusion and thus more clearly delineate cerebral pathologies including stroke, hypoxic-ischemic injury and focal lesions such as tumors and vascular malformations. It can be applied not only in infants with open fontanelles but also in older children and adults via a transtemporal window or surgically created acoustic window. Advancements in CEUS technology and post-processing methods for quantitative analysis of UCA kinetics further elucidate cerebral microcirculation. In this review article we discuss the CEUS examination protocol for brain imaging in children, current clinical applications and future directions for research and clinical uses of brain CEUS.

Contrast-enhanced ultrasound for musculoskeletal indications in children.

The increasing use of contrast-enhanced ultrasound (CEUS) has opened exciting new frontiers for musculoskeletal applications in adults and children. The most common musculoskeletal-related CEUS applications in adults are for detecting inflammatory joint diseases, imaging skeletal muscles and tendon perfusion, imaging postoperative viability of osseous and osseocutaneous tissue flaps, and evaluating the malignant potential of soft-tissue masses. Pediatric musculoskeletal-related CEUS has been applied for imaging juvenile idiopathic arthritis and Legg-Calvé-Perthes disease and for evaluating femoral head perfusion following surgical hip reduction in children with developmental hip dysplasia. CEUS can improve visualization of the capillary network in superficial and deep tissues and also in states of slow- or low-volume blood flow. In addition, measurements of blood flow imaging parameters performed by quantitative CEUS are valuable when monitoring the outcome of treatment interventions. In this review article we present current experience regarding a wide range of CEUS applications in musculoskeletal conditions in adults and children, with emphasis on the latter, and discuss imaging techniques and CEUS findings in musculoskeletal applications.

Contrast-enhanced ultrasound of the spleen, pancreas and gallbladder in children.

Gray-scale and color/power Doppler ultrasound (US) are the first-line imaging modalities to evaluate the spleen, gallbladder and pancreas in children. The increasing use of contrast-enhanced ultrasound (CEUS) as a reliable and safe method to evaluate liver lesions in the pediatric population promises potential for imaging other internal organs. Although CEUS applications of the spleen, gallbladder and pancreas have been well described in adults, they have not been fully explored in children. In this manuscript, we present an overview of the applications of CEUS for normal variants and diseases affecting the spleen, gallbladder and pancreas. We highlight a variety of cases as examples of how CEUS can serve in the diagnosis and follow-up for such diseases in children. Our discussion includes specific examination techniques; presentation of the main imaging findings in various benign and malignant lesions of the spleen, gallbladder and pancreas in children; and acknowledgment of the limitations of CEUS for these organs.

Contrast-enhanced voiding urosonography part 2: urethral imaging.

Ultrasound (US) has been increasingly used as an important imaging tool to assess the urethra in children. The earliest reports of pediatric urethral sonography involved imaging the urethra in a non-voiding state, during physiological voiding of urine, and after instillation of saline. The introduction of US contrast agents has continued to improve visualization of urethral anatomy. Contrast-enhanced US of the urethra can be performed during the voiding phase of a standard contrast-enhanced voiding urosonography (ceVUS) exam or with retrograde instillation of a contrast agent, depending on the exam indication. Both techniques are well tolerated by children and provide accurate information about urethral pathology and periurethral soft tissues. This article reviews the technical aspects and imaging findings of urethral pathologies in children using contrast-enhanced US, both by the voiding and retrograde instillation techniques.

Interobserver and Intra-Observer Reliability of the Urinary Tract Dilation Classification System in Neonates: A Multicenter Study.

PURPOSE: The Urinary Tract Dilation classification system was designed to be more objective and reproducible than currently available grading systems. We evaluated the reliability and consistency of the system in newborns. MATERIALS AND METHODS: Of 1,046 infants 0 to 90 days old undergoing ultrasound for hydronephrosis 243 were randomly selected for study inclusion. Seven readers (4 radiologists and 3 urologists) at 4 institutions classified complete, de-identified ultrasound studies on a Web based platform. Interobserver and intra-observer agreement was evaluated using the Fleiss kappa statistic. RESULTS: Interobserver agreement for Urinary Tract Dilation risk score was moderate among the 7 readers (kappa = 0.421, 95% CI 0.404-0.438). Interobserver agreement using the Society for Fetal Urology scale was worse than with the Urinary Tract Dilation classification (kappa = 0.344, 95% CI 0.330-0.359). All 7 readers assigned the same Urinary Tract Dilation score in 19.3% of cases (47 of 243). In 38.7% of cases (94 of 243) at least 3 readers assigned a Urinary Tract Dilation score different from that assigned by the other readers. In 7% of cases (17 of 243) at least 3 readers assigned a score of P0/P1, while at least 3 readers scored the same cases as P2/P3. At least 3 different Urinary Tract Dilation risk scores were assigned to the same patient in 30.45% of patients (74 of 243). Among individual Urinary Tract Dilation elements calyceal dilatation and bladder status had the highest disagreement. Five readers regraded 80 cases and agreed with their previous Urinary Tract Dilation risk score in 63.8% to 75.0% of cases (kappa 0.458 to 0.729). CONCLUSIONS: Interobserver agreement using the Urinary Tract Dilation grading system is fair to moderate, with variable agreement on individual elements of the system. Agreement was higher for the Urinary Tract Dilation system compared to the Society for Fetal Urology scale.

Prenatal imaging throughout gestation in Beckwith-Wiedemann syndrome.

PURPOSE: Prenatal occurrence and timing of appearance of associated features in Beckwith-Wiedemann syndrome (BWS) are unknown. We reviewed our BWS patients with serial fetal imaging and correlated these with postnatal findings. METHODS: All BWS patients with fetal ultrasound (US) or magnetic resonance imaging (MRI) from 2000 to 2016 were reviewed to determine the presence of polyhydramnios, placentamegaly, macrosomia, macroglossia, retrognathia, omphalocele, visceromegaly, and hemihypertrophy. These observations were correlated with postnatal findings. Data were analyzed by Mann-Whitney U test. RESULTS: Nine BWS patients underwent 42 fetal imaging studies with median of five (range of two to six) studies per patient between 13 and 35 weeks gestation. All prenatal findings were confirmed postnatally with complete concordance. All patients with omphalocele were detected early in gestation but other postnatal findings less predictably so. All omphaloceles were small, and were found significantly earlier in gestation than macrosomia (P = 0.004) and macroglossia (P = 0.012). Visceromegaly and retrognathia were less frequent, with no significant differences in median gestational age from omphalocele when prenatally identified. CONCLUSIONS: In BWS, omphalocele is the most common prenatal finding and routinely observed in early gestation with 100% accuracy. Associated findings of macrosomia, macroglossia, visceromegaly, and retrognathia, when present, are detected later in gestation. Imaging in later gestation may reveal additional abnormalities that support a BWS diagnosis.

Pediatric contrast-enhanced ultrasound in the United States: a survey by the Contrast-Enhanced Ultrasound Task Force of the Society for Pediatric Radiology.

BACKGROUND: The United States Food and Drug Administration (FDA) recently approved an ultrasound (US) contrast agent for intravenous and intravesical administration in children. OBJECTIVE: Survey the usage, interest in and barriers for contrast-enhanced US among pediatric radiologists. MATERIALS AND METHODS: The Contrast-Enhanced Ultrasound Task Force of the Society for Pediatric Radiology (SPR) surveyed the membership of the SPR in January 2017 regarding their current use and opinions about contrast-enhanced US in pediatrics. RESULTS: The majority (51.1%, 166) of the 325 respondents (26.7% of 1,218) practice in either a university- or academic affiliated group. The most widely used US contrast agent was Lumason® 52.3% (23/44). While lack of expertise and training were reported barriers, all respondents who are not currently using US contrast agents are considering future use. CONCLUSION: Interest in pediatric contrast US is very high. Education and training are needed to support members who plan to adopt contrast US into practice.

Early Outcomes of Vein Grafting for Reconstruction of Brachial Arterial Injuries in Children.

PURPOSE: We postulated that, with microsurgical technique, vascular reconstruction with interpositional vein grafts in the pediatric population is safe and results in sustained vascular patency and excellent midterm outcomes. METHODS: Twenty children with brachial artery injuries were treated with interpositional vein grafting at a tertiary pediatric hospital from 1995 to 2013. Medical records were evaluated for demographic, clinical, and radiographic data. Ten patients were available for longer-term follow-up. Pain at rest, pain with exercise, and temperature intolerance were assessed with visual analog scale (VAS) (range, 0-5). Functional outcomes were assessed using the Pediatric Outcomes Data Collection Instrument (PODCI) and Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaires. Graft patency and flow were characterized via duplex sonography. Peak flow velocity and resistive index (RI) were compared with the contralateral extremity. Median patient age at the time of injury was 7.75 years (range, 4.6-11.5 years) and median follow-up was 1.75 years (range, 0.3-6.3 years). RESULTS: All patients had perfused hands with palpable radial pulses at follow-up. There were no clinically meaningful differences in motion, sensibility, or strength between affected and unaffected limbs. Mean VAS scores for pain at rest, pain with exercise, and temperature intolerance were 0.4, 0.4, and 0.6, respectively. Mean global PODCI and DASH scores were 98.0 and 5.1, respectively. Nine of 10 patients had patent arteries with normal flow patterns. In the patient with graft occlusion, there was collateralization around the elbow with normal reconstitution of the distal vessels. Mean peak flow velocity proximal and distal to the graft were 77.7 cm/s and 66.5 cm/s, respectively. Mean RI of the graft were 0.84 and 0.77, respectively. CONCLUSIONS: Brachial artery reconstruction using interpositional vein graft and microsurgical technique is safe and effective and results in excellent functional outcomes in children. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Fetal lung apparent diffusion coefficient measurement using diffusion-weighted MRI at 3 Tesla: Correlation with gestational age.

PURPOSE: To evaluate the feasibility of using diffusion-weighted magnetic resonance imaging (DW-MRI) to assess the fetal lung apparent diffusion coefficient (ADC) at 3 Tesla (T). MATERIALS AND METHODS: Seventy-one pregnant women (32 second trimester, 39 third trimester) were scanned with a twice-refocused Echo-planar diffusion-weighted imaging sequence with 6 different b-values in 3 orthogonal diffusion orientations at 3T. After each scan, a region-of-interest (ROI) mask was drawn to select a region in the fetal lung and an automated robust maximum likelihood estimation algorithm was used to compute the ADC parameter. The amount of motion in each scan was visually rated. RESULTS: When scans with unacceptable levels of motion were eliminated, the lung ADC values showed a strong association with gestational age (P < 0.01), increasing dramatically between 16 and 27 weeks and then achieving a plateau around 27 weeks. CONCLUSION: We show that to get reliable estimates of ADC values of fetal lungs, a multiple b-value acquisition, where motion is either corrected or considered, can be performed. J. Magn. Reson. Imaging 2016;44:1650-1655.

Intrarenal Reflux: Diagnosis at Contrast-Enhanced Voiding Urosonography.

Vesicoureteral reflux (VUR) is a childhood condition that is usually diagnosed by fluoroscopic voiding cystourethrography (VCUG). Intrarenal reflux (IRR) of infected urine is believed to play an important role in the pathogenesis of reflux-associated pyelonephritis and subsequent parenchymal scarring and is traditionally depicted by fluoroscopic VCUG. This case series describes the phenomenon of IRR occurring in association with VUR in 4 children as depicted by contrast-enhanced voiding urosonography. The ability of contrast-enhanced voiding urosonography to show IRR when it occurs in conjunction with VUR compares favorably to that of fluoroscopic VCUG.

Residual intravesical iodinated contrast: a potential cause of false-negative reflux study at contrast-enhanced voiding urosonography.

A 9-month-old girl underwent conventional cyclic voiding cystourethrography (VCUG) followed immediately by cyclic contrast-enhanced voiding urosonography (ceVUS). Although the VCUG showed unilateral grade II reflux, the ceVUS showed no reflux. Images from the ceVUS showed posterior dependent layering of the denser iodinated contrast in the bladder. This layering likely prevented reflux of US microbubbles resulting in a false-negative ceVUS. To our knowledge, this potential pitfall has not yet been reported.

Human fetal sacrococcygeal extension or 'tail' in the second trimester: prenatal diagnosis, associated findings, and clinical outcome.

BACKGROUND: There are over 30 cases of prenatally diagnosed sacral extensions or human 'tails' in the literature, including isolated and syndromic etiologies. Most cases were reported to resolve by the second trimester and postnatal course was benign. Our objective was to describe the prenatal findings, associated anomalies, and clinical outcome of a series of seven fetuses diagnosed prenatally with fetal sacrococcygeal extension. METHODS: In a prospective study on a series of 4040 consecutive patients seen through our clinic in a 10-year period, 7 patients had a sacrococcygeal extension identified on fetal imaging. Fetal sonographic and magnetic resonance imaging findings, results of genetic testing, and clinical outcomes were analyzed. RESULTS: All seven fetuses had associated anomalies, including neurologic, craniofacial, cardiac, spinal, renal, and musculoskeletal abnormalities, or abnormal ultrasound findings including growth restriction and abnormal umbilical cord Doppler. There were two cases of trisomy 13 and one case of Pfeiffer syndrome. The mean gestational age at diagnosis was 19.3 weeks. CONCLUSION: When a sacrococcygeal extension is seen on fetal imaging, work-up should include detailed fetal imaging and karyotype, and fetal growth should be monitored. Our experience with fetal sacrococcygeal extension demonstrates variability in the underlying presentation and etiology, making counseling in a prenatal setting challenging.

Accuracy of contrast-enhanced voiding urosonography using Optison™ for diagnosis of vesicoureteral reflux in children.

BACKGROUND: There is limited quality of evidence regarding the accuracy of contrast-enhanced voiding urosonography (ceVUS) for diagnosis of vesicoureteral reflux (VUR) compared to fluoroscopic voiding cystourethrography (VCUG), and minimal data on the use of the ultrasound contrast agent Optison™ for this purpose. OBJECTIVE: To compare the accuracy of ceVUS using Optison™ to VCUG, and to assess inter-rater agreement regarding presence and grading of VUR. STUDY DESIGN: In this retrospective investigation, all sequential ceVUS with Optison™ and VCUG studies performed in children between 2014 and 2017 were reviewed. Two raters independently graded all ceVUS studies using a 5-point scale. CeVUS sensitivity and specificity were estimated separately for each rater using the VCUG report as the ground truth for presence and degree of VUR. Logistic and ordinary linear regression models assessed rater-report agreement and inter-rater agreement for each kidney, Optison™ dose, and referral diagnosis. RESULTS: 97 children (51 females) with 101 paired studies were included. Sensitivity and specificity of ceVUS for VUR detection were identical for both raters: right kidney 75%/90.9%; left kidney 85.7%/78.9% (Figure). There was no statistically significant difference in disagreement between raters and the VCUG report for the right or left kidney. Inter-rater agreement on ceVUS grading was 90% and 88% for right and left kidneys, respectively. There was a significant negative association between fetal hydronephrosis vs urinary tract infection and disagreement between Rater 2 and the VCUG report for the left kidney. There were no other significant associations with respect to either kidney, Optison™ dose, or referral diagnosis. DISCUSSION: Our study showed that detection of VUR with ceVUS and Optison™ is comparable to fluoroscopic VCUG. Based on the VCUG reports, the incidence of VUR in our patient population was substantially lower than in the meta-analysis of Chua et al. and in the study of Kim et al. The explanation for the large discrepancy in VUR incidence may reflect differences in the patient populations, and in our reporting of VUR with respect to kidney number rather than to pelviureteral units. Study limitations include its retrospective nature and potential bias in terms of patient selection. Since VUR is an intermittent phenomenon, sequential rather than simultaneous performance of the ceVUS and fluoroscopic studies might have influenced VUR detection. CONCLUSION: A blinded comparison of ceVUS performed with Optison™ to fluoroscopic VCUG showed moderate-good sensitivity and specificity for diagnosis of VUR.

A prospective study of expectant observation as primary therapy for neuroblastoma in young infants: a Children's Oncology Group study.

OBJECTIVE: To demonstrate that expectant observation of young infants with small adrenal masses would result in excellent event-free and overall survival. BACKGROUND: Neuroblastoma is the most common malignant tumor in infants, and in young infants, 90% of neuroblastomas are located in the adrenal gland. Although surgical resection is standard therapy, multiple observations suggest that expectant observation could be a safe alternative for infants younger than 6 months who have small adrenal masses. METHODS: A prospective study of infants younger than 6 months with small adrenal masses and no evidence of spreading beyond the primary tumor was performed at participating Children's Oncology Group institutions. Parents could choose observation or immediate surgical resection. Serial abdominal sonograms and urinary vanillylmandelic acid and homovanillic acid measurements were performed during a 90-week interval. Infants experiencing a 50% increase in the volume of the mass, urine catecholamine values, or an increase in the homovanillic acid to vanillylmandelic acid ratio greater than 2, were referred for surgical resection. RESULTS: Eighty-seven eligible patients were enrolled: 83 elected observation and 4 chose immediate surgery. Sixteen observational patients ultimately had surgery; 8 had International Neuroblastoma Staging System stage 1 neuroblastoma, 2 had higher staged neuroblastoma (2B and 4S), 2 had low-grade adrenocortical neoplasm, 2 had adrenal hemorrhage, and 2 had extralobar pulmonary sequestration. The 2 patients with adrenocortical tumors were resected because of a more than 50% increase in tumor volume. The 3-year event-free survival for a neuroblastoma event was 97.7 ± 2.2% within the entire cohort of patients (n = 87). The 3-year overall survival was 100%, with a median follow-up of 3.2 years. Eighty-one percent of patients on the observation arm were spared resection. CONCLUSIONS: Expectant observation of infants younger than 6 months with small adrenal masses led to excellent event-free survival and overall survival while avoiding surgical intervention in a large majority of the patients.

Identifying ureteropelvic junction obstruction by fluorescence imaging: a comparative study of imaging modalities to assess renal function and degree of obstruction in a mouse model.

PURPOSE: Radiological imaging is the mainstay of diagnosing ureteropelvic junction obstruction. Current established radiological modalities can potentially differentiate the varying degrees of obstruction but they are limited in functionality, applicability and/or comprehensiveness. Of particular concern is that some tests require radiation, which has long-term consequences, especially in children. MATERIALS AND METHODS: We investigated the novel use of Genhance™ 680 dynamic fluorescence imaging to assess ureteropelvic junction obstruction in 20 mice that underwent partial or complete unilateral ureteral obstruction. Ultrasound, mercaptoacetyltriglycine renography, magnetic resonance imaging and fluorescence imaging were performed. RESULTS: Our model of partial and complete obstruction could be distinguished by ultrasound, mercaptoacetyltriglycine renography and magnetic resonance imaging, and was confirmed by histological analysis. Using fluorescence imaging distinct vascular and urinary parameters were identified in the partial and complete obstruction groups compared to controls. CONCLUSIONS: Fluorescence imaging is a feasible alternative radiological imaging modality to diagnose ureteropelvic junction obstruction. It provides continuous, detailed imaging without the risk of radiation exposure.