Imaging of Fontan-Associated Liver Disease.

ABSTRACT: The Fontan procedure is the definitive treatment for patients with single-ventricle physiology. Surgical advances have led to a growing number of patients surviving into adulthood. Fontan-associated liver disease (FALD) encompasses a spectrum of pathologic liver changes that occur secondary to altered physiology including congestion, fibrosis, and the development of liver masses. Assessment of FALD is difficult and relies on using imaging alongside of clinical, laboratory, and pathology information. Ultrasound, computed tomography, and magnetic resonance imaging are capable of demonstrating physiologic and hepatic parenchymal abnormalities commonly seen in FALD. Several novel imaging techniques including magnetic resonance elastography are under study for use as biomarkers for FALD progression. Imaging has a central role in detection and characterization of liver masses as benign or malignant. Benign FNH-like masses are commonly encountered; however, these can display atypical features and be mistaken for hepatocellular carcinoma (HCC). Fontan patients are at elevated risk for HCC, which is a feared complication and has a poor prognosis in this population. While imaging screening for HCC is widely advocated, no consensus has been reached regarding an optimal surveillance regimen.

Optimizing Imaging of Pediatric Liver Lesions: Guidelines from the Pediatric LI-RADS Working Group.

A differential diagnosis based on a patient's age, clinical presentation, and serum α-fetoprotein level will help guide the initial imaging workup in children with a liver lesion. Children vary significantly in size, the ability to stay still, and the ability to breath hold for imaging examinations. Choosing and tailoring imaging techniques and protocols for each indication and age group is important for optimal care with minimal invasiveness. The need for sedation or anesthesia can be obviated by using techniques like feed and bundle, distraction, contrast-enhanced US, and motion-insensitive sequences for MRI. US is often the first imaging modality used in children with a suspected abdominal mass. Once a hepatic lesion is confirmed, multiphasic contrast-enhanced MRI is recommended for most lesions as the next imaging modality allowing full characterization of the lesion and assessment of the liver parenchyma. Contrast-enhanced CT can also be performed for assessment of pediatric focal liver lesions, especially in patients who have a contraindication to MRI. Contrast-enhanced US has shown promise to decrease the need for MRI or CT in some lesions such as hemangioma and focal nodular hyperplasia. Children with a history of malignancy can develop multiple types of hepatic lesions at various stages, including infections during an immunocompromised state, manifesting as focal liver lesions. Based on available limited data in the literature and the collective experiences of the Liver Imaging and Reporting Data System Pediatric Working Group, the authors provide guidelines for the imaging workup of pediatric focal liver lesions with an indication- and age-based approach and discuss the selection and performance of various imaging techniques and modalities. ©RSNA, 2022 See the invited commentary by Chojniak and Boaventura in this issue.

Cancer Therapy-related Hepatic Injury in Children: Imaging Review from the Pediatric LI-RADS Working Group.

The liver is the primary organ for the metabolism of many chemotherapeutic agents. Treatment-induced liver injury is common in children undergoing cancer therapy. Hepatic injury occurs due to various mechanisms, including biochemical cytotoxicity, hepatic vascular injury, radiation-induced cytotoxicity, and direct hepatic injury through minimally invasive and invasive surgical treatments. Treatment-induced liver injury can be seen contemporaneous with therapy and months to years after therapy is complete. Patients can develop a combination of hepatic injuries manifesting during and after treatment. Acute toxic effects of cancer therapy in children include hepatitis, steatosis, steatohepatitis, cholestasis, hemosiderosis, and vascular injury. Longer-term effects of cancer therapy include hepatic fibrosis, chronic liver failure, and development of focal liver lesions. Quantitative imaging techniques can provide useful metrics for disease diagnosis and monitoring, especially in treatment-related diffuse liver injury such as hepatic steatosis and steatohepatitis, hepatic iron deposition, and hepatic fibrosis. Focal liver lesions, including those developing as a result of treatment-related vascular injury such as focal nodular hyperplasia-like lesions and hepatic perfusion anomalies, as well as hepatic infections occurring as a consequence of immune suppression, can be anxiety provoking and confused with recurrent malignancy or hepatic metastases, although there often are imaging features that help elucidate the correct diagnosis. Radiologic evaluation, in conjunction with clinical and biochemical screening, is integral to diagnosing and monitoring hepatic complications of cancer therapy in pediatric patients during therapy and after therapy completion for long-term surveillance. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material See the invited commentary by Ferraciolli and Gee in this issue.

Prevention of Allergic-like Reactions at Repeat CT: Steroid Pretreatment versus Contrast Material Substitution.

Background It is unclear whether steroid premedication is an effective means of preventing repeat allergic-like reactions in high-risk patients with a previous allergic-like reaction to iodinated contrast material (ICM). Purpose To compare the effectiveness of ICM substitution (ie, using iohexol in a patient with a previous iopromide reaction) with 12- and 2-hour steroid premedication for preventing repeat acute allergic-like reactions in high-risk patients. Materials and Methods This retrospective study identified all high-risk (ie, having a previous allergic-like reaction) adult and pediatric patients who underwent a contrast-enhanced CT examination at the institution from June 1, 2009, to May 9, 2017. Prophylactic treatments and repeat reactions were identified using chart review. The effectiveness of prophylactic treatments on repeat reaction rates was examined with multivariable regression models that used generalized estimating equations. Results A total of 1973 high-risk patients who underwent 4360 subsequent ICM-enhanced CT examinations were included. Of the 4360 examinations, a total of 280 allergic-like reactions occurred (6%) in 224 of the 1973 patients (11% of patients), with only 19 of 280 reactions (7%) that were more severe than the previous reaction being demonstrated. After adjustment, patients who received a different ICM with and without steroid premedication had a significantly lower rate of repeat reactions than did patients who received steroid premedication and the same ICM (same ICM and steroid premedication: 80 of 423 examinations [19%]; different ICM and no steroid premedication: 10 of 322 examinations [3%]; odds ratio [OR], 0.14 [95% CI: 0.06, 0.33]; P < .001; different ICM and steroid premedication: five of 166 patients [3%]; OR, 0.12 [95% CI: 0.04, 0.36]; P < .001). When examining the first scan only, patients who received the same ICM had a similar risk of repeat reactions regardless of whether they received steroid premedication (steroid premedication: 44 of 172 patients [26%] vs no premedication: 73 of 298 patients [25%]; OR, 1.00 [95% CI: 0.64, 1.57]; P = .99). Conclusion In this cohort, using an iodinated contrast material (ICM) substitution was more effective for preventing repeat allergic-like reactions than using steroid premedication and the same ICM that caused the previous reaction. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Davenport and Weinstein in this issue.

Acute Reactions to Gadolinium-Based Contrast Agents in a Pediatric Cohort: A Retrospective Study of 16,237 Injections.

BACKGROUND. Incidences and risk factors for acute reactions to gadolinium-based contrast agents (GBCAs) are not fully understood, particularly in pediatric patients. OBJECTIVE. The purpose of this study was to retrospectively examine allergiclike and physiologic acute reactions in pediatric patients who receive GBCAs for MRI examinations. METHODS. The study cohort consisted of all pediatric patients (age < 18 years old) who underwent an MRI examination with a GBCA at our institution from June 1, 2009, to May 9, 2017. Acute reactions were identified by medical record review and classified by severity using the American College of Radiology guidelines. Potential risk factors for reactions were examined using generalized estimating equation methods accounting for rare events. RESULTS. A total of 16,237 GBCA injections (10,141 gadodiamide injections, 4880 gadobutrol injections, and 1216 gadobenate dimeglumine injections) were administered to a study cohort of 10,190 patients (49% [7982/16,237] girls and 51% [8255/16,237] boys). Incidences of 0.10% (17/16,237) for allergiclike and 0.14% (23/16,237) for physiologic reactions were observed. No severe reactions occurred. Allergiclike reaction incidences were significantly higher with gadobenate compared with gadodiamide (0.49% vs 0.04%; p < .001) and in patients who underwent abdominal or pelvic MRI examinations (0.38%) or cardiac examinations (0.55%) compared with head examinations (0.05%; p < .001 and p = .006, respectively). Physiologic reaction incidences were significantly higher in older patients (0.25% in patients 12-17 years old vs 0.03% in patients 2 to < 12 years old; p < .001) and in patients who underwent abdominal or pelvic examinations compared with head examinations (0.38% vs 0.10%; p = .002). Of 16 MRI examinations performed in patients with a prior allergiclike reaction to GBCAs, only one resulted in a repeat reaction. CONCLUSION. In this pediatric cohort, GBCA type, patient age, and MRI type were risk factors for acute reactions. Repeat reactions were rare. CLINICAL IMPACT. Providers must weigh the risks and benefits when choosing a particular GBCA to use in their practices and must consider multiple, potentially disparate risks associated with each GBCA.

Asymptomatic macrocephaly: to scan or not to scan.

BACKGROUND: Macrocephaly is a common finding in infants and is often idiopathic or familial. In the absence of clinical signs and symptoms, it can be difficult to determine when concern for underlying pathology is justified. OBJECTIVES: The objectives of this study were to determine the utility of screening head ultrasound (US) in asymptomatic infants with macrocephaly and to identify clinical factors associated with significant US findings. MATERIALS AND METHODS: A 20-year retrospective review was performed of infants undergoing head US for macrocephaly or rapidly increasing head circumference. Data collected included age, gender, head circumference at birth and at the time of US, specialty of the ordering physician, US findings, computed tomography (CT) or magnetic resonance imaging (MRI) findings, and clinical course including interventions. RESULTS: Four hundred and forty infants met inclusion criteria. Two hundred and eighty studies (64%) were found to be normal, 137 (31%) had incidental findings, 17 (3.8%) had indeterminate but potentially significant findings, and 6 (1.4%) had significant findings. Twenty of the 23 infants with indeterminate or significant findings had subsequent CT or MRI. This confirmed significant findings in eight infants (1.8%): three subdural hematomas, two intracranial tumors, two aqueductal stenoses, and one middle fossa cyst. Five of the eight infants required surgical procedures. The only statistically significant association found with having a significant finding on head US was head circumference at birth. CONCLUSION: Ultrasound is a useful initial study to evaluate infantile macrocephaly, identifying several treatable causes in our study and, when negative, effectively excluding significant pathology.

Imaging pediatric acute appendicitis during the coronavirus disease 2019 (COVID-19) pandemic: collateral damage is variable.

BACKGROUND: Since coronavirus disease 2019 (COVID-19) was declared a worldwide pandemic in March 2020, many authors have noted the collateral damage on non-COVID-19-related illnesses. These indirect effects of the pandemic have resulted in people presenting later and with more severe stages of disease, even if their diagnoses are not directly related to SARS-CoV-2, the virus that causes COVID-19. OBJECTIVE: We studied these indirect effects of COVID-19 on the imaging workup and outcomes for pediatric patients at our center who had acute appendicitis during the pandemic. MATERIALS AND METHODS: We performed a retrospective review of cases in children ≤18 years who were evaluated for acute appendicitis during the same period, March 1 to May 31, in both 2019 and 2020. We compared demographic and clinical data as well as surgical and pathological findings, and we graded imaging findings according to severity. Differences in patient outcomes were assessed using the Wilcoxon rank sum test and the Pearson chi-square test. RESULTS: The total number of pediatric patients evaluated with imaging for acute appendicitis dropped by 43% between 2019 and 2020 (298 vs. 169), but the total number of children treated remained similar (59 vs. 51). There was proportionate use of US and CT in each timeframe but a higher percentage of positive imaging findings in 2020 (50/169, 29.6% vs. 56/298, 18.7% in 2019, P=0.04). There were more imaging examinations with features of complicated appendicitis among positive cases (9/51, 18% vs. 5/59, 8% in 2019, P=0.08) and more pathologically proven perforated cases during the pandemic (14/51, 27% vs. 6/59, 10% in 2019, P=0.11), although these results did not reach statistical significance. There were no changes in surgical management, vital signs, laboratory values, length of stay or complication rates. CONCLUSION: There was a large drop in the number of pediatric patients imaged for acute appendicitis during the acute phase of the COVID-19 pandemic despite similar numbers of patients treated. The utilization trends of US vs. CT remained stable between time periods. The differences in imaging findings and perforation rates were less pronounced compared to other published studies.

Reproducibility of Lung and Liver Volume Measurements on Fetal Magnetic Resonance Imaging in Left-Sided Congenital Diaphragmatic Hernia.

INTRODUCTION: Congenital diaphragmatic hernia (CDH) affects 1 in 3,000 live births and is associated with significant morbidity and mortality. METHODS: A review of fetal magnetic resonance imaging (MRI) examinations was performed for fetuses with left CDH and normal lung controls. Image review and manual tracings were performed by 4 pediatric radiologists; right and left lung volumes in the coronal and axial planes as well as liver volume above and below the diaphragm in the coronal plane were measured. Intra- and interreviewer reproducibility was assessed using intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS: Excellent intra- and interreviewer reproducibility of the right and left lung volume measurements was observed in both axial planes (interreviewer ICC: right lung: 0.97, 95% CI: 0.95-0.99; left lung: 0.97, 95% CI: 0.95-0.98) and coronal planes (interreviewer ICC: right lung: 0.97, 95% CI: 0.95-0.98; left lung: 0.96, 95% CI: 0.93-0.98). Moderate-to-good interreviewer reproducibility was observed for liver volume above the diaphragm (ICC 0.7, 95% CI: 0.59-0.81). Liver volume below the diaphragm had a good-to-excellent interreviewer reproducibility (ICC 0.88, 95% CI: 9.82-0.93). CONCLUSIONS: The present study demonstrated an excellent intra- and interreviewer reproducibility of MRI lung volume measurements and good-to-moderate inter- and intrareviewer reproducibility of liver volume measurements after standardization of the methods at our fetal center.

Sequential Minimally Invasive Fetal Interventions for Two Life-Threatening Conditions: A Novel Approach.

INTRODUCTION: In utero interventions are performed in fetuses with "isolated" major congenital anomalies to improve neonatal outcomes and quality of life. Sequential in utero interventions to treat 2 anomalies in 1 fetus have not yet been described. CASE PRESENTATION: Here, we report a fetus with a large left-sided intralobar bronchopulmonary sequestration (BPS) causing mediastinal shift, a small extralobar BPS, and concomitant severe left-sided congenital diaphragmatic hernia (CDH). At 26-week gestation, the BPS was noted to be increasing in size with a significant reduction in right lung volume and progression to fetal hydrops. The fetus underwent ultrasound-guided ablation of the BPS feeding vessel leading to complete tumor regression. However, lung development remained poor (O/E-LHR: 0.22) due to the left-sided CDH, prompting fetal endoscopic tracheal occlusion therapy at 28-week gestation to allow increased lung growth. After vaginal delivery, the newborn underwent diaphragmatic repair with resection of the extralobar sequestration. He was discharged home with tracheostomy on room air at 9 months. DISCUSSION/CONCLUSION: Sequential in utero interventions to treat 2 severe major anomalies in the same fetus have not been previously described. This approach may be a useful alternative in select cases with otherwise high morbidity/mortality. Further studies are required to confirm our hypothesis.

Quantitative Inflammation Assessment for Crohn Disease Using Ultrasensitive Ultrasound Microvessel Imaging: A Pilot Study.

OBJECTIVES: Crohn disease (CD) is a chronic inflammation in the digestive tract that affects millions of Americans. Bowel vascularity has important diagnostic information because inflammation is associated with blood flow changes. We recently developed an ultrasensitive ultrasound microvessel imaging (UMI) technique with high vessel sensitivity. This study aimed to evaluate the feasibility of UMI to assist CD detection and staging. METHODS: Ultrasound microvessel imaging was performed on 76 bowel wall segments from 48 symptomatic patients with CD. Clinically indicated computed tomographic/magnetic resonance enterography was used as the reference standard. The vessel-length ratio (VLR, the number of vessel pixels in the bowel wall segment normalized to the segment length) was derived in both conventional color flow imaging (CFI) and UMI to quantitatively stage disease activity. Receiver operating characteristic curves were then analyzed between different disease groups. RESULTS: The VLR-CFI and VLR-UMI detected similar correlations between vascularization and disease activity: severe inflammation had a higher VLR than normal/mildly inflamed bowels (P < .05). No significant difference was found between quiescent and mild CD due to the small sample size. The VLR-CFI had more difficulties in distinguishing quiescent versus mild CD compared to the VLR-UMI. After combining the VLR-UMI with thickness, in the receiver operating characteristic curve analysis, the areas under the curves (AUCs) improved to AUC1 = 0.996 for active versus quiescent CD, AUC2 = 0.978 for quiescent versus mild CD, and AUC3 = 0.931 for mild versus severe CD, respectively, compared to those using thickness alone (AUC1 = 0.968; P = .04; AUC2 = 0.919; P = .16; AUC3 = 0.857; P = .01). CONCLUSIONS: Ultrasound microvessel imaging offers a safe and cost-effective tool for CD diagnosis and staging, which may potentially assist disease activity classification and therapy efficacy evaluation.

Acute Adverse Events Following Gadolinium-based Contrast Agent Administration: A Single-Center Retrospective Study of 281 945 Injections.

Background Acute allergic-like and physiologic reactions occur following administration of gadolinium-based contrast agents (GBCAs) for MRI examinations. Because these reactions are uncommon, it is challenging to compare reaction rates between GBCAs and to determine risk factors. Purpose To compare reaction rates between the four GBCAs gadodiamide, gadobutrol, gadobenate dimeglumine, and gadoterate meglumine, and to determine potential risk factors for reactions. Materials and Methods This retrospective study identified all intravenous GBCA injections for MRI examinations performed at a single institution from June 1, 2009, to May 9, 2017. Reactions were identified by reviewing records from the MRI technologist, MRI nursing staff, radiologist, emergency department, and provider. Reactions were classified as allergic-like or physiologic and as mild, moderate, or severe by using American College of Radiology criteria. GBCA reaction rates and other potential risk factors were examined by using multivariable regression models with generalized estimating equations. Results Analysis included a total of 158 100 patients (median age, 55 years [interquartile range, 40-67 years], 51% women) who received a total of 281 945 GBCA injections (140 645 gadodiamide, 94 109 gadobutrol, 39 138 gadobenate, and 8053 gadoterate). At multivariate analysis, gadobenate or gadobutrol had higher rates of allergic-like reactions compared with gadodiamide (gadobenate: odds ratio [OR], 3.9 [95% confidence interval {CI}: 3.0, 5.1]; P < .001; gadobutrol: OR, 2.3 [95% CI: 1.8, 2.9]; P < .001) or gadoterate (gadobenate: OR, 4.8 [95% CI: 1.0, 23]; P = .049; gadobutrol: OR, 2.8 [95% CI: 0.6, 14]; P = .20). Physiologic reactions were more frequently observed with gadoterate (OR, 7.7 [95% CI: 2.3, 25; P = .001), gadobenate (OR, 1.8 [95% CI: 1.3, 2.5; P < .001), and gadobutrol (OR, 1.6 [95% CI: 1.3, 2.1; P < .001) administration compared with gadodiamide. Six severe allergic-like reactions (three gadobutrol, three gadobenate) occurred requiring hospitalization. Patient age (P values .025 to < .001), sex (P < .001), location (P = .006), and MRI type (P = .003 and P = .006) were associated with acute reactions. Conclusion Gadobenate and gadobutrol are associated with higher rates of allergic-like reactions compared with gadodiamide or gadoterate, and gadoterate, gadobenate, and gadobutrol are associated with higher rates of physiologic reactions compared with gadodiamide. Patient sex, age, location, and MRI type correlate with acute reaction rates. © RSNA, 2019 Online supplemental material is available for this article.

Pediatric ileocolic intussusception: new observations and unexpected implications.

BACKGROUND: Ileocolic intussusception occurs when the terminal ileum "telescopes" into the colon. We observed that ileocolic intussusception lengths are similar regardless of location in the colon. OBJECTIVE: To examine the uniformity of ileocolic intussusception length and its relationship to colon location, symptom duration and reducibility. MATERIALS AND METHODS: We retrospectively reviewed ultrasound-diagnosed pediatric ileocolic intussusceptions initially treated with pneumatic reduction at the Mayo Clinic or Texas Children's Hospital. We recorded demographic, imaging and surgical findings including age, gender, symptom duration, location of the ileocolic intussusception, reducibility with air enema and, if fluoroscopically irreducible, surgical findings. RESULTS: We identified 119 ileocolic intussusceptions (64% boys), with 81% in the right colon. There was no significant relationship between ileocolic intussusception length and colon location (P=0.15), nor ileocolic intussusception length and symptom duration (P=0.36). Ileocolic intussusceptions were more distal with increasing symptom duration (P=0.016). Successful reductions were unrelated to symptom duration (P=0.84) but were more likely with proximal versus distal locations (P=0.02). CONCLUSION: Ileocolic intussusception lengths are relatively uniform regardless of location along the course of the colon where they present. Our findings suggest that most of the apparent distal propagation of ileocolic intussusceptions is not caused by increasing telescoping of small bowel across the ileocecal valve but rather by foreshortening of the right colon. This implies poor cecal fixation and confirms fluoroscopic and surgical observations of cecal displacement from the right lower quadrant with ileocolic intussusceptions. The movement of the leading edge of the ileocolic intussusception during reduction is first due to "relocating" the cecum into the right lower quadrant after which the reduction of small bowel back across the ileocecal valve then occurs.

Correction to: Pediatric ileocolic intussusception: new observations and unexpected implications.

In this article, the fourth author's name is misspelled. The correct spelling, as shown above, should be "Nadia F. Mahmood."

Postcontrast Acute Kidney Injury in Pediatric Patients: A Cohort Study.

RATIONAL & OBJECTIVE: The risks of iodinated contrast material administered to pediatric patients are not well defined. The purpose of this study was to examine the rates of postcontrast acute kidney injury (AKI), dialysis therapy, and death following administration of intravenous contrast material to pediatric patients. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Pediatric (aged <18 years) patients who underwent either contrast-enhanced (contrast group) or unenhanced (noncontrast group) computed tomography (CT) at our institution from December 2001 to January 2016. EXPOSURE: Intravenous iodinated contrast material. OUTCOMES: Postcontrast AKI based on serum creatinine-defined KDIGO criteria, dialysis therapy, and death. ANALYTICAL APPROACH: Risks for AKI, dialysis therapy, and death were compared between contrast and noncontrast group patients using a propensity score analysis incorporating clinical covariates related to contrast exposure. RESULTS: 2,201 pediatric patients (1,773 contrast and 428 noncontrast) were identified. Rates of AKI and dialysis therapy in the contrast group were 3.3% (59/1,773) and 0.1% (2/1,773), respectively. Following propensity score adjustment, no differences in risk for AKI (stage 1 AKI: OR, 0.75 [95% CI, 0.32-1.78], P=0.5; stage 2: OR, 2.00 [95% CI, 0.18-21.9], P=0.6; stage 3: OR, 0.50 [95% CI, 0.05-5.48], P=0.6), dialysis therapy (OR, 1.00 [95% CI, 0.06-15.9], P=0.9), or death (OR, 1.50 [95% CI, 0.53-4.22], P=0.4) were observed between the contrast and noncontrast groups. All patients with post-CT stage 3 AKI diagnosed also had contrast-independent potential causes of AKI. LIMITATIONS: The study's small sample size and low rates of postcontrast AKI, dialysis therapy, and death limited the ability to detect an effect of contrast administration on these outcomes. Unmeasured residual confounders may limit the validity of our results. Few patients had decreased kidney function at the time of CT. CONCLUSIONS: Rates of postcontrast AKI, dialysis therapy, and death following contrast-enhanced CT were very low in this pediatric cohort. Although not detectably different, an effect of contrast on these outcomes could not be ruled out.

Endoscopic Skipping of the Terminal Ileum in Pediatric Crohn Disease.

OBJECTIVE: Pediatric small-bowel (SB) Crohn disease (CD) may be missed if the terminal ileum (TI) appears normal at endoscopy and SB imaging is not performed. We sought to estimate the prevalence and clinical characteristics of pediatric patients with CD and endoscopic skipping of the TI-that is, pediatric patients with active SB or upper gut inflammation and an endoscopically normal TI. MATERIALS AND METHODS: This retrospective study included pediatric patients with CD who underwent both CT enterography (CTE) or MR enterography (MRE) and ileocolonoscopy within a 30-day period between July 2004 and April 2014. The physician global assessment was used as the reference standard for SB CD activity. Radiologists reviewed the CTE and MRE studies for inflammatory parameters; severity, length, and multifocality of SB inflammation; and the presence of penetrating complications. RESULTS: Of 170 patients who underwent ileal intubation, the TI was macroscopically normal or showed nonspecific inflammation in 73 patients (43%). Nearly half (36/73, 49%) of the patients with normal or nonspecific findings at ileocolonoscopy had radiologically active disease with a median length of SB involvement of 20 cm (range, 1 to > 100 cm). Seventeen (47%) of these patients had multifocal SB involvement and five (14%) had penetrating complications. Overall, endoscopic TI skipping was present in 43 (59%) patients with normal or nonspecific ileocolonoscopic findings: 20 with histologic inflammation (17 with positive imaging findings), 14 with inflammation at imaging only, and nine with proximal disease (upper gut, jejunum, or proximal ileum). There were no significant differences in the clinical parameters of the patients with and those without endoscopic TI skipping. CONCLUSION: Ileocolonoscopy may miss SB CD in pediatric patients that is due to isolated histologic, intramural, or proximal inflammation. Enterography is complementary to ileocolonoscopy in the evaluation of pediatric CD.

Radiological Response Is Associated With Better Long-Term Outcomes and Is a Potential Treatment Target in Patients With Small Bowel Crohn's Disease.

OBJECTIVES: Crohn's disease (CD) management targets mucosal healing on ileocolonoscopy as a treatment goal. We hypothesized that radiologic response is also associated with better long-term outcomes. METHODS: Small bowel CD patients between 1 January 2002 and 31 October 2014 were identified. All patients had pre-therapy computed tomography enterography (CTE)/magnetic resonance enterography (MRE) with follow-up CTE or MRE after 6 months, or 2 CTE/MREs≥6 months apart while on maintenance therapy. Radiologists characterized inflammation in up to five small bowel lesions per patient. At second CTE/MRE, complete responders had all improved lesions, non-responders had worsening or new lesions, and partial responders had other scenarios. CD-related outcomes of corticosteroid usage, hospitalization, and surgery were assessed using Kaplan-Meier survival analysis and multivariable Cox models. RESULTS: CD patients (n=150), with a median disease duration of 9 years, had 223 inflamed small bowel segments (76 with strictures and 62 with penetrating, non-perianal disease), 49% having ileal distribution. Fifty-five patients (37%) were complete radiologic responders, 39 partial (26%), and 56 non-responders (37%). In multivariable Cox models, complete and partial response decreased risk for steroid usage by over 50% (hazard ratio (HR)s: 0.37 (95% confidence interval (CI), 0.21-0.64); 0.45 (95% CI, 0.26-0.79)), and complete response decreased the risk of subsequent hospitalizations and surgery by over two-thirds (HRs: HR, 0.28 (95% CI, 0.15-0.50); HR, 0.34 (95% CI, 0.18-0.63)). CONCLUSIONS: Radiological response to medical therapy is associated with significant reductions in long-term risk of hospitalization, surgery, or corticosteroid usage among small bowel CD patients. These findings suggest the significance of radiological response as a treatment target.

Evaluation of Patient Tolerance and Small-Bowel Distention With a New Small-Bowel Distending Agent for Enterography.

OBJECTIVE: The objective of our study was to compare a flavored beverage containing a thickening agent for enterography with a low-Hounsfield-value barium suspension for side effects, taste, subjects' willingness to repeat the drinking protocol, and small-bowel distention. SUBJECTS AND METHODS: The following five drinking protocols were administered to 10 volunteers: 1000 mL of flavored beverage followed by 350 mL of water, 1500 mL of flavored beverage, 900 mL of low-Hounsfield-value barium suspension followed by 450 mL of water, 1350 mL of low-Hounsfield-value barium suspension followed by 150 mL of water, and 1500 mL of water. MR images were obtained 50 and 60 minutes after initiation of drinking. Subjects completed a questionnaire evaluating the side effects, the taste of the drink, and their willingness to repeat the drinking protocol. Reviewers assigned scores evaluating small-bowel distention and ranked the examinations in order of preference. RESULTS: There was no significant difference in nausea or vomiting among the protocols (p = 0.20 and 0.42, respectively), but larger volumes of flavored beverage and low-Hounsfield-value barium suspension resulted in more cramping and diarrhea (p = 0.001 and 0.002, respectively). The taste of the low-Hounsfield-value barium suspension was rated the worst (p < 0.0001). The subjects' willingness to repeat the drinking protocol was highest for the 1000 mL of flavored beverage or water alone (p < 0.05). There were no significant differences in subjective small-bowel distention except that water was rated the worst by two of the three readers (p < 0.02). There was no significant difference in the diameter of the most dis-tended small bowel for any segment or reader (p > 0.23). CONCLUSION: A flavored beverage containing a thickening agent has a similar side effect profile and results in equivalent small-bowel distention compared with a low-Hounsfield-value barium suspension, but subjects rate taste and their willingness to repeat the drinking protocol higher for this new agent.

Upright Biplanar Slot Scanning in Pediatric Orthopedics: Applications, Advantages, and Artifacts.

OBJECTIVE: Digital slot scanning is a relatively new technology that has been used for imaging of pediatric orthopedic conditions such as scoliosis and leg-length discrepancies. This article will review the clinical applications, advantages, and unique artifacts of this new technology. CONCLUSION: Upright biplanar slot scanners acquire high-resolution radiographs simultaneously in two orthogonal planes with reduced radiation dose. Other advantages include a more physiologic weightbearing imaging position, improved Cobb angle measurements, and 3D modeling.

CT enterography: technical and interpretive pitfalls.

CT enterography is a first-line test at many institutions to investigate potential small bowel disorders. While numerous articles have focused on the ability of CT enterography to diagnose and stage Crohn's disease, small bowel neoplasia, and malabsorptive or vascular disorders, this article reviews CT enterography limitations, technical and interpretive pitfalls, image review tactics, and complementary radiologic and endoscopic examinations to improve diagnostic accuracy. CT enterography limitations include its inability to demonstrate isolated mucosal abnormalities such as aphthous ulcers and its use of ionizing radiation. The most common technical pitfall of CT enterography is inadequate small bowel distention resulting from inadequate ingestion, gastric retention, or rapid small bowel transit of a large volume of neutral enteric contrast material. Additionally, segments of jejunum are frequently collapsed. Interpretive pitfalls commonly result from peristaltic contractions, transient intussusception and opaque intraluminal debris. Opaque debris is especially problematic during multiphasic CT enterography performed to identify potential small bowel sources of obscure gastrointestinal bleeding. False-negative examinations may result from inadequate radiation dose. Examinations complementary to CT enterography include small bowel follow through, enteroclysis, CT enteroclysis, MR enterography, MR enteroclysis, capsule endoscopy, and balloon-assisted endoscopy. Properly performed and accurately interpreted CT enterography contributes to the diagnosis and management of small bowel disease by itself and as a complement to other radiologic and optical small bowel imaging examinations.