Accuracy of controlled attenuation parameter compared with ultrasound for detecting hepatic steatosis in children with severe obesity.

OBJECTIVES: To determine the diagnostic accuracy of controlled attenuation parameter (CAP) on FibroScan® in detecting and grading steatosis in a screening setting and perform a head-to-head comparison with conventional B-mode ultrasound. METHODS: Sixty children with severe obesity (median BMI z-score 3.37; median age 13.7 years) were evaluated. All underwent CAP and US using a standardized scoring system. Magnetic resonance spectroscopy proton density fat fraction (MRS-PDFF) was used as a reference standard. RESULTS: Steatosis was present in 36/60 (60%) children. The areas under the ROC (AUROC) of CAP for the detection of grade ≥ S1, ≥ S2, and ≥ S3 steatosis were 0.80 (95% CI: 0.67-0.89), 0.77 (95% CI: 0.65-0.87), and 0.79 (95% CI: 0.66-0.88), respectively. The AUROC of US for the detection of grade ≥ S1 steatosis was 0.68 (95% CI: 0.55-0.80) and not significantly different from that of CAP (p = 0.09). For detecting ≥ S1 steatosis, using the optimal cutoffs, CAP (277 dB/m) and US (US steatosis score ≥ 2) had a sensitivity of 75% and 61% and a specificity of 75% and 71%, respectively. When using echogenicity of liver parenchyma as only the scoring item, US had a sensitivity of 70% and specificity of 46% to detect ≥ S1 steatosis. The difference in specificity of CAP and US when using only echogenicity of liver parenchyma of 29% was significant (p = 0.04). CONCLUSION: The overall performance of CAP is not significantly better than that of US in detecting steatosis in children with obesity, provided that the standardized scoring of US features is applied. When US is based on liver echogenicity only, CAP outperforms US in screening for any steatosis (≥ S1). KEY POINTS: • The areas under the ROC curves of CAP and ultrasound (US) for detecting grade ≥ S1 steatosis were 0.80 and 0.68, respectively, and were not significantly different (p = 0.09). • For detecting grade ≥ S1 steatosis in severely obese children, CAP had a sensitivity of 75% and a specificity of 75% at its optimal cutoff value of 277 dB/m. • For detecting grade ≥ S1 steatosis in clinical practice, both CAP and US can be used, provided that the standardized scoring of US images is used.

Radiation Exposure From Pediatric CT Scans and Subsequent Cancer Risk in the Netherlands.

BACKGROUND: Computed tomography (CT), a strong diagnostic tool, delivers higher radiation doses than most imaging modalities. As CT use has increased rapidly, radiation protection is important, particularly among children. We evaluate leukemia and brain tumor risk following exposure to low-dose ionizing radiation from CT scans in childhood. METHODS: For a nationwide retrospective cohort of 168 394 children who received one or more CT scans in a Dutch hospital between 1979 and 2012 who were younger than age 18 years, we obtained cancer incidence, vital status, and confounder information by record linkage with external registries. Standardized incidence ratios were calculated using cancer incidence rates from the general Dutch population. Excess relative risks (ERRs) per 100 mGy organ dose were calculated with Poisson regression. All statistical tests were two-sided. RESULTS: Standardized incidence ratios were elevated for all cancer sites. Mean cumulative bone marrow doses were 9.5 mGy at the end of follow-up, and leukemia risk (excluding myelodysplastic syndrome) was not associated with cumulative bone marrow dose (44 cases). Cumulative brain dose was on average 38.5 mGy and was statistically significantly associated with risk for malignant and nonmalignant brain tumors combined (ERR/100 mGy: 0.86, 95% confidence interval = 0.20 to 2.22, P = .002, 84 cases). Excluding tuberous sclerosis complex patients did not substantially change the risk. CONCLUSIONS: We found evidence that CT-related radiation exposure increases brain tumor risk. No association was observed for leukemia. Compared with the general population, incidence of brain tumors was higher in the cohort of children with CT scans, requiring cautious interpretation of the findings.

The impact of reconstruction techniques on observer performance for the detection and characterization of small pulmonary nodules in chest CT of children under 13 years.

OBJECTIVE: To compare three different reconstruction techniques of CT data for the detection of pulmonary nodules in children under 13 years. Secondly to assess the prevalence of perifissural nodular opacities. MATERIALS AND METHODS: The study consisted of chest CTs of 31 children (median age 6.9 years, range 2.1-12.7), of whom 17 had known extra-thoracic malignancies. Four observers assessed three techniques for the presence of nodules: axial 5 mm maximum intensity projections (MIPs) used in conjunction with 1 mm slices (mode A), 1 mm slices alone (mode B) and 3 mm slices (mode C). All modes were available in 3D. Per mode sensitivities were determined above a certain threshold of reader agreement. Confidence level and reader agreement for identification of an opacity as nodule served as surrogate for quality of nodule characterization. RESULTS: 103 nodules (median size 2.0 mm) were detected. Mode A yielded the highest interreader agreement (κ 0.336) and a superior sensitivity (71%, p = 0.003) compared to mode B and C (κ 0.218, sensitivity 57% and κ 0.247, sensitivity 56%, respectively). Mode B provided the highest confidence level and interreader agreement with respect to nodule identification (mean 4.3/5, κw 0.508). Double reading improved and evened interreader agreement for all modes (κ 0.450), mode A maintained the highest sensitivity (89.1%, p = 0.05-0.08). A median of 1 intrapulmonary lymph node/patient was seen in children with and without malignancy. CONCLUSION: MIP improves the detection of pulmonary nodules in chest CTs of children, but overall interreader agreement is only fair. Double reading represents a powerful tool to increase diagnostic reliability in chest CTs of children with a malignancy. Nodule characterization is best with 1 mm slices. Intrapulmonary lymph nodes occur in children with and without malignancy.

Chronic Complications After Femoral Central Venous Catheter-related Thrombosis in Critically Ill Children.

Prescription of thromboprophylaxis is not a common practice in pediatric intensive care units. Most thrombi are catheter-related and asymptomatic, without causing acute complications. However, chronic complications of these (a)symptomatic catheter-related thrombi, that is, postthrombotic syndrome (PTS) and residual thrombosis have not been studied. To investigate these complications, critically ill children of 1 tertiary center with percutaneous inserted femoral central venous catheters (FCVCs) were prospectively followed. Symptomatic FCVC-thrombosis occurred in 10 of the 134 children (7.5%; 95% confidence interval [CI], 2.4-9.5). Only FCVC-infection appeared to be independently associated (P=0.001) with FCVC-thrombosis. At follow-up 2 of the 5 survivors diagnosed with symptomatic thrombosis developed mild PTS; one of them had an occluded vein on ultrasonography. A survivor without PTS had a partial occluded vein at follow-up. Asymptomatic FCVC-thrombosis occurred in 3 of the 42 children (7.1%; 95% CI, 0.0-16.7) screened by ultrasonography within 72 hours after catheter removal. At follow-up, mild PTS was present in 6 of the 33 (18.2%; 95% CI, 6.1-30.3) screened children. Partial and total vein occlusion was present in 1 (3%) and 4 (12%) children, respectively. In conclusion, children on pediatric intensive care units are at risk for (a)symptomatic FCVC-thrombosis, especially children with FCVC-infection. Chronic complications of FCVC-thrombosis are common. Therefore, thromboprophylaxis guidelines are warranted in pediatric intensive care units to minimize morbidity as a result of FCVC-thrombosis.

Accuracy of abdominal ultrasound and MRI for detection of Crohn disease and ulcerative colitis in children.

BACKGROUND: Endoscopy is currently the primary diagnostic technique for inflammatory bowel disease (IBD) in children. OBJECTIVE: To assess the accuracy of US and dynamic contrast-enhanced MRI for diagnosing inflammatory bowel disease and for distinguishing Crohn disease and ulcerative colitis in comparison to a reference standard. MATERIALS AND METHODS: Consecutive children with suspected IBD underwent diagnostic workup including ileocolonoscopy and upper gastrointestinal endoscopy as the reference standard, abdominal US, and MR enterography and colonography at 3 T. The protocol included a dynamic contrast-enhanced 3-D sequence. Sensitivity, specificity and kappa values were calculated for one ultrasonographer and two MRI observers. RESULTS: We included 28 children (15 boys) with mean age 14 years (range 10-17 years). The diagnosis was IBD in 23 children (72%), including 12 with Crohn disease, 10 with ulcerative colitis and 1 with indeterminate colitis. For the diagnosis of inflammatory bowel disease the sensitivity was 55% for US and 57% (both observers) for MR entero- and colonography, and the specificity was 100% for US and 100% (observer 1) and 75% (observer 2) for MR entero- and colonography. Combined MRI and US had sensitivity and specificity of 70% and 100% (observer 1) and 74% and 80% (observer 2), respectively. With the addition of a dynamic contrast-enhanced MR sequence, the sensitivity increased to 83% and 87%. US and MRI could only distinguish between Crohn disease and ulcerative colitis when terminal ileum lesions were present. CONCLUSION: US and MR entero- and colonography have a high accuracy for diagnosing inflammatory bowel disease in children but cannot be used to distinguish Crohn disease and ulcerative colitis.

Leukemia and brain tumors among children after radiation exposure from CT scans: design and methodological opportunities of the Dutch Pediatric CT Study.

Computed tomography (CT) scans are indispensable in modern medicine; however, the spectacular rise in global use coupled with relatively high doses of ionizing radiation per examination have raised radiation protection concerns. Children are of particular concern because they are more sensitive to radiation-induced cancer compared with adults and have a long lifespan to express harmful effects which may offset clinical benefits of performing a scan. This paper describes the design and methodology of a nationwide study, the Dutch Pediatric CT Study, regarding risk of leukemia and brain tumors in children after radiation exposure from CT scans. It is a retrospective record-linkage cohort study with an expected number of 100,000 children who received at least one electronically archived CT scan covering the calendar period since the introduction of digital archiving until 2012. Information on all archived CT scans of these children will be obtained, including date of examination, scanned body part and radiologist's report, as well as the machine settings required for organ dose estimation. We will obtain cancer incidence by record linkage with external databases. In this article, we describe several approaches to the collection of data on archived CT scans, the estimation of radiation doses and the assessment of confounding. The proposed approaches provide useful strategies for data collection and confounder assessment for general retrospective record-linkage studies, particular those using hospital databases on radiological procedures for the assessment of exposure to ionizing or non-ionizing radiation.

The contribution of chest CT-scan at diagnosis in children with unilateral Wilms' tumour. Results of the SIOP 2001 study.

BACKGROUND: The SIOP 2001 nephroblastoma study hypothesised that patients with 'CT-only' pulmonary nodules would have the same outcome as patients with localised disease of same stage and histology. PATIENTS: Unilateral Wilms' tumour (WT) patients, who had chest CT scans at diagnosis showing any sized pulmonary nodules undetected on chest X-ray, between November 2001 and November 2009, were selected from the SIOP 2001 database. RESULTS: Among 2532 WT patients, 103 unilateral nephroblastoma patients with CT-only lung lesions were found. Thirty-seven patients received preoperative treatment according to the localised-disease protocol, and 66 according to the metastatic-disease protocol. The 3-year event-free survival (EFS) was 70% (95% CI: 55-89%) and 77% (95% CI: 66-89%), respectively. Corresponding 3-year overall survival (OS) was 89% (95% CI: 77-100%) and 85% (95% CI: 75-96%), respectively (p-value not significant). EFS and OS of all 2071 patients with true localised disease were 87% (95% CI: 86-89%) and 96% (95% CI: 94-97%), respectively. Patients with metastatic disease (n = 358) had 3-year EFS and OS estimates of 68% (95% CI: 63-74%) and 77% (95% CI: 72-82%), respectively. CONCLUSIONS: EFS and OS of patients with CT-only lung lesions were inferior to that of true localised-disease patients and superior to that of patients with metastatic disease. However, no significant difference was found in EFS and OS between CT-only patients treated for localised or metastatic disease. The clinician's preference to treat patients with CT-only pulmonary nodules as metastatic disease is not evidence-based. Chest CT at diagnosis does not improve outcome but presents paediatric oncologists with a difficult dilemma.

Magnetic resonance enterography for suspected inflammatory bowel disease in a pediatric population.

OBJECTIVES: The aim of the study was to determine the accuracy of magnetic resonance enterography (MRE) in diagnosing and differentiating pediatric inflammatory bowel disease (IBD). The secondary aims were to determine the accuracy of MRE in grading disease activity and determine the interobserver agreement for individual MRE parameters. PATIENTS AND METHODS: Pediatric patients scheduled to undergo esophagogastroduodenoscopy, ileocolonoscopy with biopsies, and barium enteroclysis for suspected IBD were included and underwent MRE. MRE images were evaluated by 3 observers. The accuracy of MRE was calculated using the clinical diagnosis based on endoscopic, histopathological, and barium enteroclysis examinations as reference standard. RESULTS: Thirty-three patients were available for analysis. IBD was correctly diagnosed in, respectively, 61%, 61%, and 91% of the patients by the 3 observers, with a specificity of 80%, 90%, and 60%. Differentiation between Crohn disease (CD) and ulcerative colitis (UC) was accurately done in, respectively, 67%, 53%, and 80% of patients with CD and 0%, 14%, and 43% of patients with UC. Disease activity was understaged on MRE in the majority of patients. Intraclass correlation coefficients for measurements of bowel thickness were 0.52 (observer 1-2; observer 1-3) and 0.34 (observer 2-3). Interobserver agreement on bowel wall enhancement and stenosis was moderate to good (κ 0.59, 0.56, and 0.56 and κ 0.62, 0.32, 0.30, respectively). CONCLUSIONS: Sensitivity and specificity values of MRE for diagnosing pediatric IBD were moderate to good. CD, but not UC, was accurately diagnosed by MRE in a large proportion of patients. Activity was understaged in a large proportion of patients. Interobserver agreement for individual MRE parameters was fair to good.

The sonographic characteristics of nontuberculous mycobacterial cervicofacial lymphadenitis in children.

BACKGROUND: Nontuberculous mycobacteria (NTM) are a common cause of chronic cervicofacial lymphadenitis in young children. The differential diagnosis includes other infections, lymphoepithelial cysts and malignancies. OBJECTIVE: To assess the sonographic findings of NTM cervicofacial lymphadenitis in children. MATERIALS AND METHODS: We analysed the sonograms of cervicofacial lymph nodes of 145 children with microbiologically proven NTM lymphadenitis. RESULTS: The size of the involved lymph nodes ranged from 1.9 cm to 4.4 cm. Most of the NTM patients (85%) presented in a stage of lymph node fluctuation with violaceous skin discoloration. On sonography, marked decreased echogenicity was seen in all cases. In 133 of the patients (92%) liquefaction with intranodal cystic necrosis, nodal matting and adjacent soft-tissue oedema were present. 66 children received antibiotic treatment, and the other children underwent surgical excision of the involved lymph nodes. In 69% of the patients successfully treated with antibiotics, multiple intranodal calcifications were present on sonography after 1 year. CONCLUSIONS: Sonographic findings can provide additional diagnostic clues for NTM lymphadenitis in childhood. A marked decrease of echogenicity in the early stages, with intranodal liquefaction in the advanced stages, are universal features, albeit not entirely specific. Multiple intranodal calcifications are rather characteristic of end-stage mycobacterial infection.

Diagnosis of Hirschsprung's disease: a prospective, comparative accuracy study of common tests.

OBJECTIVE: To compare the diagnostic accuracy of contrast enema (CE), anorectal manometry (ARM), and rectal suction biopsy (RSB) for the detection of Hirschsprung's disease (HD). STUDY DESIGN: Following a prospective protocol, infants suspected of HD underwent all 3 index tests. Children with positive results on 2 or more index tests or who continued to have severe bowel problems underwent a full thickness biopsy as reference standard. Clinical follow-up was the reference standard in all other children. RESULTS: Between 2000 and 2003, 111 consecutive patients (67 boys; median age, 5.3 months) in whom HD was suspected were enrolled. HD was found in 28 patients. RSB had the highest sensitivity (93%) and specificity (100%) rates, but values were not significantly different from CE (sensitivity, 76%; specificity, 97%) or from ARM (sensitivity, 83%; specificity, 93%). Inconclusive test results occurred in 8 infants with CE, in 15 infants with ARM because of agitation, and in 2 infants with RSB. CONCLUSION: RSB is the most accurate test for diagnosing HD, and it has the lowest rate of inconclusive test results.