Prospective Validation of the Lémann Index in Children: A Report From the Multicentre Image Kids Study.

BACKGROUND: The Lémann Index [LI] and the recently updated LI are tools for measuring structural bowel damage in adults with Crohn's disease [CD] but have not been evaluated in children. We aimed to validate the updated LI in the prospective multicentre ImageKids study of paediatric CD. METHODS: We included children with CD undergoing magnetic resonance enterography [MRE], pelvic magnetic resonance imaging [MRI] and ileocolonoscopy. Half were followed for 18 months, when MRE was repeated. Serum was collected for fibrosis-related proteomic markers. The LI was calculated by central readers from the MRE, ileocolonoscopy, physical examination and surgical data. Reliability and construct validity were assessed at baseline, while responsiveness and test-retest reliability were explored longitudinally. RESULTS: In total, 240 children were included (mean age, 14.2 ± 2.5 years; median disease duration, 2.2 years [interquartile range, IQR 0.25-4.42]; median baseline LI, 4.23 [IQR 2.0-8.8]). The updated LI had excellent inter-observer reliability (interclass correlation coefficient [ICC] = 0.94, 95% confidence interval [CI] 0.92-0.95) but poor, although statistically significant, correlation with radiologist and gastroenterologist global assessments of damage and with serum proteomic levels of fibrotic markers [rho = 0.15-0.30, most p < 0.05]. The updated LI had low discriminative validity for detecting damage (area under the receiver operating characteristic curve [AUC-ROC] 0.69, 95% CI 0.62-0.75). In 116 repeated MREs, responsiveness was suboptimal for differentiating improved from unchanged disease [AUC-ROC 0.58, 95% CI 0.45-0.71]. Test-retest reliability was high among stable patients [ICC = 0.84, 95% CI 0.72-0.91]. CONCLUSION: Overall, the updated LI had insufficient psychometric performance for recommending its use in children. An age-specific index may be needed for children with shorter disease duration than typical adult cohorts.

Magnetic Resonance Enterography Cannot Replace Upper Endoscopy in Pediatric Crohn Disease: An Imagekids Sub-study.

OBJECTIVES: Although magnetic resonance enterography (MRE) can accurately reflect ileal inflammation in pediatric Crohn disease (CD), there are no pediatric data on the accuracy of MRE to detect upper gastrointestinal tract (UGI) lesions. We aimed to compare MRE and esophagogastroduodenoscopy (EGD) in detecting the spectrum and severity of UGI disease in children. METHODS: This is an ancillary study of the prospective multi-center ImageKids study focusing on pediatric MRE. EGD was performed within 2 weeks of MRE (at disease onset or thereafter) and explicitly scored by SES-CD modified for the UGI and physician global assessment. Local and central radiologists scored the UGI region of the MRE blinded to the EGD. Accuracy of MRE compared with EGD was examined using correlational coefficients (r) and area under receiver operating characteristic curves (AUC). RESULTS: One hundred and eighty-eight patients were reviewed (mean age 14 ±â€Š1 years, 103 [55%] boys); 66 of 188 (35%) children had macroscopic ulcerations on EGD (esophagus, 13 [7%]; stomach, 34 [18%]; duodenum, 45 [24%]). Most children had aphthous ulcers, but 10 (5%) had larger ulcers (stomach, 2 [1%]; duodenum, 8 [4%]). There was no agreement between local and central radiologists on the presence or absence of UGI inflammation on MRE (Kappa = -0.02, P = 0.71). EGD findings were not accurately detected by MRE, read locally or centrally (r = -0.03 to 0.11, P = 0.18-0.88; AUC = 0.47-0.55, P = 0.53-1.00).No fistulae or narrowings were identified on either EGD or MRE. CONCLUSIONS: MRE cannot reliably assess the UGI in pediatric CD and cannot replace EGD for this purpose.

Sonographic Bands of Hypoechogenicity in the Spleen in Children: Zebra Spleen.

OBJECTIVE: Zebra spleen is the normal pattern of splenic enhancement during the arterial phase of CT and MRI and is attributed to different flow rates. The purpose of this study was to describe the appearance and occurrence of bands of hypoechogenicity in the spleen on unenhanced sonograms of children with no splenic abnormalities. MATERIALS AND METHODS: We reviewed 100 abdominal ultrasound studies to evaluate the ultrasound characteristics of the spleen. Demographic data were collected for all patients. RESULTS: Homogeneous echogenicity of the spleen was found in 92 children. Heterogeneous echogenicity was present in eight. Three of the eight had discrete macronodules due to known splenic disease. The other five had bands of hypoechogenicity. These five had no known splenic disease, but one had mild splenomegaly of unknown cause. CONCLUSION: The pattern of hypoechoic bands occurred in 5% of our series. This pattern cannot be explained simply by different flow rates and probably reflects different structural components of the parenchyma. At ultrasound this pattern should be considered a normal finding that may simulate a splenic mass.