1) To review basic concepts in fetal abdominal wall defects (AWD). 2) To identify basic imaging tricks to correctly identify each AWD. 3) To review prenatal/postnatal treatments of these AWD.

msm@ucsd.edu

The purpose of this study was to assess cross-sectional and longitudinal diagnostic performance of hepatic proton density fat fraction (PDFF) to grade histologic steatosis in children with nonalcoholic fatty liver disease (NAFLD) using centrally-scored histology as the reference standard.

We assessed the performance of magnetic resonance imaging (MRI) proton density fat fraction (PDFF) in children to stratify hepatic steatosis grade before and after treatment in the Cysteamine Bitartrate Delayed-Release for the Treatment of Nonalcoholic Fatty Liver Disease in Children (CyNCh) trial, using centrally-scored histology as reference. This study was conducted at nine clinical centers in the United States, with centrally-evaluated MRI. Participants had multi-echo 1.5T or 3T MRI on scanners from three manufacturers.

Of 169 enrolled children, 110 (65%) and 83 (49%) had MRI and liver biopsy at baseline and at end-of-treatment (EOT; 52-weeks), respectively. At baseline, 17% (19/110), 28% (31/110), and 55% (60/110) of liver biopsies showed grades 1, 2, and 3 histologic steatosis; corresponding PDFF (mean ± standard deviation) values were 10.9 ± 4.1%, 18.4 ± 6.2%, and 25.7 ± 9.7%, respectively. PDFF classified grade 1 vs. 2-3 and 1-2 vs. 3 steatosis with areas under receiving operator characteristic curves (AUROCs) of 0.87 (95% confidence interval [CI]: 0.80, 0.94) and 0.79 (0.70, 0.87), respectively. PDFF cut-offs at 90% specificity were 17.5% for grades 2-3 steatosis, and 23.3% for grade 3 steatosis. At EOT, 47% (39/83), 41% (34/83), and 12% (10/83) of biopsies showed improved, unchanged, and worsened steatosis grade, respectively, with corresponding PDFF (mean ± standard deviation) changes of -7.8 ± 6.3%, -1.2 ± 7.8% and 4.9 ± 5.0%, respectively. PDFF change classified steatosis grade improvement and worsening with AUROCs of (95% CI) of 0.76 (0.66, 0.87) and 0.83 (0.73, 0.92), respectively. PDFF change cut-off values at 90% specificity were -11.0% and +5.5% for improvement and worsening.

MRI-estimated PDFF has high diagnostic accuracy to both classify and predict histologic steatosis grade, and change in histologic steatosis grade in children with NAFLD.

Our study results support the feasibility of using MRI-estimated PDFF in multi-center pediatric clinical trials as a biomarker of hepatic steatosis, and of change in hepatic steatosis.

zhouly6@mail.sysu.edu.cn

To investigate the value of Supersonic shear-wave elastography (SSWE) in the assessment of hepatic fibrosis in patients with biliary atresia (BA) and to analyze factors that might influence the SSWE value.

The ethics committee approved this study, and informed parental consent was obtained. From January 2012 to January 2016, sixty-seven infants with BA who preoperatively had SSWE measurements and consequently underwent Kasai portoenterostomy were ruled in. All patients were also underwent preoperative serologic testing. Interoperative liver specimens were reviewed in a blinded manner by two pathologists using METAVIR criteria. SSWE measurements were correlated with pathological results, age and serologic testing results.Performance of SSWE in differentiating liver fibrosis was determined by using areas under the receiver operating characteristic curve (AUCs).

The SSWE value of F0 (n=1), F1 (n=16), F2 (n=28), F3 (n=18), F4 (n=4) was 8.2Kpa,11.0(8.4-12.2)Kpa,12.6(10.1-13.9)Kpa,16.6(14.7-24.0)Kpa,20.3(13.4-37.2)Kpa, respectively. SSWE value were significantly correlated with γ-glutamyltranspeptidase(P=0.010), age(P<0.001) and liver fibrosis P<0.001). Logistic regression analysis demonstrated that liver fibrosis(P<0.001) and age(P=0.033)were significantly associated with SSWE. The AUC for differentiating severe fibrosis or greater (>=F3) was 0.896, with an optimal cutoff value of 13.2 Kpa.

Preoperative SSWE measurements for infants with BA could be used as a noninvasive tool for prodicting severe fibrosis or geater (>=F3). However, SSWE value might be influenced by infant's age.

The severity of liver fibrosis at the time of surgery is predictive of the long-term success of portenterostomy. For BA infants with severe liver fibrosis, direct liver transplantation may be a better choice over portenterostomy. Thus, Preoperative SSWE measurements for infants with BA may help decide whether a Kasai surgery or a direct liver transplantation is better for infants with BA. Furthermore, the severity of liver fibrosis reflected by SSWE vaule may also be important in predicting the outcome of Kasai surgery.

mhzaghal@hotmail.com

MR enterography (MRE) with contrast injection is the imaging modality of choice for diagnosing and monitoring Crohn's disease (CD). Since recent studies described intracranial gadolinium depositions in patients undergoing repeated contrast-enhanced MRI's, efforts have been made to reduce the use of gadolinium. Diffusion-weighted Imaging (DWI) sequence enables to detect inflammatory changes without the use of gadolinium. Our purpose is to estimate the accuracy and efficacy of DWI sequences in MRE (DWI-MRE) for assessment of CD in children.

This study utilized 50 MRE's of children with CD performed as part of the large prospective ImageKids study in which children underwent MRE and ileocolonoscopy. MRE's were re-read, first, without the contrast injection sequences (DWI-MRE) and then including post contrast sequences (CE-MRE). Parameters evaluated in both readings included: involved segment, segment length, degree of inflammation, degree of fibrosis and severity of disease (inflammation and fibrosis). Comparisons were made between the different parameters in both readings and with Simple Endoscopic Score for Crohn's Disease (SES-CD) of the terminal Ileum (TI).

Comparison of DWI-MRE to CE-MRE: Affected bowel segments were identified with accuracy> 85% in the upper gastrointestinal tract, TI and colon. Accuracy was 82% in the ileum and 80% in the jejunum. Pearson correlation coefficient (PCC) for severity of disease was 0.86 in the colon and rectum, 0.81 in the jejunum, 0.77 in the ileum and 0.68 in the TI. PCC between the two readings for inflammation was 0.74 (jejunum), 0.68 (ileum), 0.7 (colon). PCC for fibrosis was highest for colon (0.68) but lower for the small intestine. PCC for segment length between the readings was 0.76 (colon), 0.61 (jejunum), 0.65 (TI). Comparison of MRE to SES-CD: PCC of 0.64 for degree of inflammation between the DWI-MRE and SES-CD and PCC of 0.52 for severity of disease between CE-MRE and SES-CD.

DWI-MRE is accurate enough for assessment of involved segments, length of segments and estimation of severity disease but less accurate for differentiating fibrotic from inflammatory lesions.

There is an increasing concern regarding sedimentation of gadolinium in the brain after multiple examinations. DE-MRE can substitute CE-MRE in CD patients subject to multiple MRE exams.

fatakshay@yahoo.com

To evaluate the role of SSWE in evaluation of infants with cholestatic jaundice.

This was a prospective observational study which was approved by the ethics committee of our institute. Infants with biochemically proven cholestatic jaundice were evaluated using SSWE of the liver. The mean Shear Wave Speed (SWS) and mean Young's Modulus (YM) in the nine Couinaud's segments of liver and at the echogenicity anterior to the right portal vein were recorded. On the basis of histopathological findings, clinical follow up and other laboratory investigations, patients were placed in two groups: EHBA and non-EHBA. Shear wave sonographic findings were compared for these two groups. Sub group analysis was performed for children < 90 days of age. P value <0.05 was considered significant. Receiver operating characteristic curves were drawn.

90 infants (58 boys, 32 girls; median age 85 days) were enrolled of which 51 were <90 days of age. There were 19 patients of EHBA of which 16 were <90 days of age. The mean SWS in the liver segments in the EHBA and Non-EHBA group were 3.43 ±0.85 m/s and 2.81 ± 0.88 m/s respectively. The mean YM in the liver segments in the EHBA and Non-EHBA group were 39.04 ± 17.40 kPa and 26.78 ± 16.70 kPa respectively. These differences were statistically significant. Although the mean SWS and YM anterior to the right portal vein were higher in the EHBA group, the differences were not statistically significant. At a cut off mean SWS value of 2.14 m/s for the liver segments, the sensitivity to diagnose EHBA was 94.7 % and the specificity was 31.0 % while with a cut off mean SWS value of 4.43 m/s, the sensitivity to diagnose EHBA was 15.8 % and the specificity was 94.4 %. Similarly, at a cut off mean YM value of 16.31 kPa for the liver segments, the sensitivity to diagnose EHBA was 94.7% and the specificity was 40.8 % while with a cut off of mean YM value of 60.88 kPa, the sensitivity to diagnose EHBA was 15.8% and the specificity was 97.2 %. For the children <90 days of age, mean SWS and YM in liver segments and anterior to right portal vein were higher in EHBA group and the differences were statistically significant.

SSWE of liver can be used to differentiate between EHBA and other etiologies of infantile cholestatic jaundice.

SSWE can be another tool in radiological armamentarium for segregating patients of EHBA from other causes of infantile cholestatic jaundice.

To determine segment-level correlation between hepatic PDFF and R2* using magnitude based (-M) and complex based (-C) MRI techniques.

In this cross-sectional study, we conducted a secondary analysis of 3T MR exams performed as part of prospective research studies in children in whom conditions associated with iron overload were excluded clinically. Each exam included low-flip-angle, multi-echo magnitude and complex based chemical-shift-encoded MRI techniques with spectral modeling of fat to generate hepatic PDFF and R2* parametric maps. For each technique and each patient, regions of interest were placed on the maps in each of the nine Couinaud segments and the corresponding segmental PDFF and R2* values were recorded. For each segment and each MR technique, correlation between PDFF and R2* values was assessed using Pearson's correlation coefficient (r). Correlations were compared using Steiger's test; Bonferroni's correction was applied.

184 children (123 boys, 61 girls) were included in this analysis. Mean ± STDEV values for segment-level PDFF estimated by MRI-M and MRI-C were 9.28 ± 8.97 % and 9.86 ± 8.98 %, respectively. Mean ± STDEV values for segment-level R2* estimated by MRI-M and MRI-C were 48.23 ± 12.39 s-1 and 41.83 ± 11.45 s-1, respectively. Segment-level correlations between PDFF and R2* ranged from 0.626 to 0.843 for MRI-M and 0.516 to 0.785 for MRI-C. All segment-level correlations were significant for both techniques (p < 0.0001). For both techniques, the highest correlations were observed in segments 4b, 5, and 6 and the lowest in segments 2, 3 and 4a. The difference in correlations between MRI-M and MRI-C techniques was significant for segments 1 and 4a, and trend-wise significant for segment 6 after Bonferroni correction.

Hepatic PDFF and R2* are correlated in each Couinaud segment using two different techniques. For both techniques, the correlations were highest for segments 5, 6, 4b, 1 and 7, and lowest for segments 2, 3 and 4a. Correlation coefficients were higher for MRI-M than for MRI-C for all segments.

Segments 4b, 5, and 6 exhibit the highest correlations between PDFF and R2*; whereas 2, 3, and 4a exhibit lower correlations than other hepatic segments. Although further validation is needed, this may be because the proximity of left lobe segments to the lungs increases the contribution of large-scale susceptibility effects on R2* estimation.

tarmstrong@mednet.ucla.edu

MRI provides non-invasive liver fat quantification, but Cartesian MRI is susceptible to motion artifacts and limited to a breath-hold (BH). In children, BH may not be possible and anesthesia is undesired. In this work, we develop a new free-breathing 3D stack-of-radial pediatric liver fat quantification technique and assess accuracy and repeatability.

FB radial showed significant correlation and low mean difference compared to BH Cartesian and BH SVS. Accurate and repeatable free-breathing PDFF quantification in children is possible using a FB radial technique.

The new FB radial technique achieves accurate and repeatable free-breathing liver fat quantification in children with NAFLD.

hawkcm@gmail.com

Understand the different devices that are available for percutaneous gastric and gastrojejunal access. Learn the basic technique involved in de novo gastric and gastrojejunal access. Learn the impact of post-procedural education on frequency of follow-up procedures.

1) Understand the different types of enteric access in children. 2) Apply appropriate patient selection when considering enteric access. 3) Understand the risks associated with different types of pediatric enteric access.

1) Review and compare systems to grade antenatal and postnatal hydronephrosis. 2) Describe etiologies of antenatal and postnatal hydronephrosis. 3) Discuss benefits and limitations of classification systems.

Prenatal ultrasound is performed throughout the world to evaluate the fetus. Detection of anomalies can dramatically alter treatment plans and help predict postnatal outcomes. Renal and bladder anomalies are relatively common. Dilatation of the urinary tract is seen in 1-2% of fetuses and can be due to a variety of etiologies. Various ultrasonographic features have been used to grade the severity of the dilatation. In March of 2014, experts representing 8 professional societies convened and created a new scoring system to standardize classification of prenatal and postnatal urinary tract dilatation (UTD). Recommendations for further evaluation of these patients were then made based on the UTD grade. This talk will review the UTD grading system and publications evaluating the new method.

mjgoette@texaschildrens.org

To evaluate the feasibility of shear wave elastography ultrasound as a potential non-invasive tool to facilitate early diagnosis of hepatic veno-occlusive disease (HVOD) in a pediatric population undergoing hematopoietic stem cell transplantation (HSCT).

Under IRB approval, HSCT patients with a clinical suspicion of HVOD were recruited for the study (N=11, age: 10.3 ± 6.4 y). Diagnosis of HVOD was made by fulfillment of the Revised Seattle Criteria as determined by a physician using the following clinical criteria: right upper quadrant pain, total bilirubin, percent weight gain, and ascites, as well as the detection of portal venous flow reversal. All patients underwent serial ultrasound examinations, which included evaluation by grayscale, Doppler, and elastographic techniques. Ten ultrasound exams were performed every other day using a GE Logic-E9 ultrasound unit with linear and curvilinear transducers. Four elastography measurements each were made in Couinaud's liver segments numbers 5 through 8 (16 total for each patient).

Of the eleven recruited patients, four completed fewer than 10 exams due to discharge or withdrawal of consent. The figure displays each patient's average SWE velocity (m/s) over all 10 exams obtained in liver segments 5 through 8. The mean SWE velocity from all patients in this population was 1.81 ± 0.18 m/s (range: 1.66 to 2.18 m/s), which was higher than the vendor specified cut-off for normal stiffness of 1.35 m/s. The patient with the highest measured SWE velocity (2.18 ± 0.28 m/s) was the only patient to die due to multi-organ failure as a complication of HVOD. This patient's SWE measurements were significantly higher than the rest of the cohort (p=0.00085), with a mean SWE velocity greater than 2.10 m/s delineating this severe patient from other patients with mild or moderate disease.

This study demonstrated elevated liver stiffness values with shear wave elastography in pediatric patients undergoing HSCT with clinically suspected HVOD, and the ability to delineate between mild and severe disease in this population.

This study demonstrates the potential diagnostic application of an emerging sonographic technique in a unique population of pediatric patients. Early detection of this disease has the potential to profoundly impact patient care.

maera.h@gmail.com

Conventionally, non-visualization of the gallbladder (GB) and small bowel (SB) on a Hepatobiliary Iminodiacetic Acid (HIDA) scan indicates biliary atresia, however results are often confounded by the presence of hepatic dysfunction resulting in a high false positive rate. We aim to provide correlation between HIDA imaging and surgical/pathologic findings, and outline an alternate method of interpretation incorporating background activity on HIDA exams to differentiate biliary atresia and hepatic dysfunction.

A retrospective study of all children under age 2 years with persistent jaundice who underwent HIDA scans at our institution between January 2002 and December 2016 followed by surgical/pathologic evaluation was performed. All HIDA scans were reviewed by a blinded pediatric radiologist; background radiotracer uptake was graded from 1+ to 3+, and visualization of the GB and SB was recorded. Increased background activity (2+, 3+) was presumed to indicate poor hepatic function. Pathology and surgical reports were used as the gold standard. Binary logistic regression analysis was used to determine correlation between HIDA and pathology findings utilizing the conventional and alternate methods of diagnosing biliary atresia.

A total of 735 HIDA scans were performed during the study period of which 61 cases met all the inclusion criteria with a male predominance of 69% and mean age of 62 days. Of these, 19 (31.1%) patients were proven to have biliary atresia and 42 (68.9%) patients to have hepatic dysfunction per the gold standard. The conventional method yielded an accuracy of 65.6% without significant correlation with the gold standard (p-0.998), whereas using the alternate method resulted in an accuracy of 83.6% with significant correlation to the gold standard (p-0.003).

Background activity grading supplemented with visualization of the SB and GB increases accuracy of diagnosis of biliary atresia versus hepatic dysfunction on HIDA scan and provides a significant correlation with findings on surgery and histopathologic evaluation.

Utilizing background activity can improve accuracy of diagnosis on HIDA scan and potentially result in avoidance of unnecessary invasive testing.

mlingura@childrensnational.org

To provide early and accurate detection of severe ureteropelvic junction obstruction requiring surgical intervention from the evaluation of the drainage curves obtained from the first diuresis renography (DR) exam. We introduce the calculation of new metrics for surgical decision-making based on advanced signal analysis and machine learning techniques.

Sixty DR studies (5 bilateral) from 55 patients (age 80±70 days) were acquired, in which 34 kidneys needed surgery and 26 did not. Surgical decision was based on the clinical evaluation of the dynamic information embedded in longitudinal DR. Posterior dynamic images of the kidneys were obtained for 30 minutes, using a Siemens e-Cam Signature with 1.0 mCi 99mTechnetium MAG3. After administration of furosemide 1 mg/Kg, additional images were obtained for 30 minutes. In this study, we used the drainage curves from the first DR of each patient. We extracted 45 features using signal analysis including curve spatio-temporal descriptors. Feature selection was done within a leave-one-out analysis, selecting a group of features for each training dataset based on their weights on a linear support vector machine classifier. A histogram of selected features was created and those that were selected at least 95% of the times were chosen as final features. Then, a linear support vector machine classifier identified surgical or non-operative cases. Our method was evaluated in terms of accuracy, sensitivity and specificity, and compared with the results obtained from the widely used t-half time, which is the time to drain half of the radiotracer from the kidney.

We predicted ureteropelvic obstruction for which surgery was performed with an accuracy of 93% (91% sensitivity, 96% specificity), compared to the accuracies of 77% (71% sensitivity, 85% specificity) and 80% (67% sensitivity, 96% specificity) obtained using thresholds of 20 and 30 min on the t-half time (p<0.05).

Our signal analysis method for drainage curves from DR studies at the time of the first exam significantly improves the detection of ureteropelvic obstruction with accuracy to 93%. Earlier detection of surgical candidates could potentially improve patient outcome.

Early detection of ureteropelvic junction obstruction has the potential to reduce the time and number of longitudinal DR exams required to determine course of treatment.

To identify changes in testicular adrenal rest tumor (TART) during long-term follow-up and to evaluate the correlation between TART volumes and hormone levels in children with congenital adrenal hyperplasia.

We retrospectively reviewed serial testicular ultrasonography and hormone levels from 39 children with congenital adrenal hyperplasia (mean age 15.7 years; range 5-19 years). The median follow-up period was 8 years (range 1-13 years). The volumes of each testis and TART were calculated using the prolate ellipsoid formula and the relative TART volume was defined as the ratio of TART volume divided by the testicular volume. Serum concentrations of renin and 17-hydroxyprogesterone (17-PG) around the time of testicular ultrasonography were collected. Serial changes in volumetric parameters of ultrasonography and hormone levels were analyzed with a linear mixed model, adjusting individual repeated measurement.

During follow-up, the mean testicular volume of all patients grew from 8.76±4.39 cm3 to 9.68±5.01 cm3. Among 39 children, thirty-six children (84.6%) had TARTs, bilaterally. At initial, the mean TART volume and mean relative TART volume were 1.16 cm3 (range, 0.0-12.3 cm3) and 0.12 (range, 0.0-0.5), respectively. The volume of TART was unchanged in 30 children and increased in 9 children (mean volume change of TART, 4.07±3.41 cm3). Among 9 children with growing volume of TART, one patient was diagnosed as having an adrenocortical carcinoma. However, there was no malignant change in testicular mass. Relative TART volume was associated with a higher risk for increasing 17-PG serum concentration (Estimate = 114.87, 95% CI = 14.8 to 214.9, P =.025). The other volumetric parameters showed no significant correlation with hormone levels.

TART grew during follow-up in 9 (23%) out of 39 children under treatment for congenital adrenal hyperplasia and relative TART showed a significant correlation with 17-PG level.

Testicular ultrasonography can be a useful imaging tool for monitoring growth of TARTs and development of malignant tumors in children with congenital adrenal hyperplasia, although these are not common.

jsparzen@gmail.com

Wilms tumor survivors have increased risk of developing late nephrotoxicity. We evaluated the prevalence of impaired renal function in survivors of Wilms tumor who were treated with radiation therapy (RT).

Patients who were under the age of 21 at the time of RT for Wilms tumor and who had at least 2 years of follow-up were eligible for the study. All patients treated with RT between 1995-2016 at this institution were included. Renal function was assessed with estimated glomerular filtration rate (eGFR) using the modified Schwartz equation. Impaired renal function was defined as eGFR <90 mL/minute/1.73m2. Secondary outcomes of interest were proteinuria and elevated systolic blood pressure (SBP).

28 patients met all inclusion parameters, with a median age at RT of 3.3 years (range, 0.4-17.5 years). There were 17 female and 11 male patients. There were 1 Stage I, 0 Stage II, 18 Stage III, 5 Stage IV, and 3 Stage V patients. RT was delivered to the hemiabdomen in 18 patients and to the whole abdomen in 10 patients. RT dose was <=1080 Gy in 19 patients and >1080 Gy in 9 patients. All patients received chemotherapy and surgery. 25 of the patients received doxorubicin, actinomycin, and vincristine. Ipsilateral nephrectomy was the most common surgical procedure, in 23 patients. At median length of follow-up of 10.0 years (range, 2.5-28.1 years), 13 (46.4%) patients had impaired renal function. No patients had developed end-stage renal disease. 6 (21.4%) patients had elevated blood pressure (SBP > 120) and 4 (14.3%) patients had proteinuria. Age <=3 at time of RT was not associated with the development of reduced eGFR (p = 0.151).

Patients requiring trimodality therapy for Wilms tumor are at substantial risk for developing late renal toxicity. Further studies are needed to clarify the effect of age at RT on the propensity to develop late nephrotoxicity.

There is a high rate of late nephrotoxicity in children receiving radiation therapy for Wilms tumor and further efforts are needed to decrease treatment-related morbidity in this patient population.

1) Review radiopharmaceuticals commonly used for imaging the pediatric urinary system. 2) Discuss current utilization of nuclear medicine for imaging the pediatric urinary system.