Normal ovarian sizes on MRI in pediatric patients: a preliminary study.

BACKGROUND: Ovarian enlargement is one of several findings of pathology, including ovarian torsion. With increasing use of MRI for acute abdominal pain in children, data for normal ovary size and appearance are needed. OBJECTIVE: To provide preliminary data on normal sizes of ovaries on MRI in pediatric patients. MATERIALS AND METHODS: This retrospective IRB-approved study included girls (5 to 17 years of age) with MRI examinations performed for indications not related to the ovaries from 2018 to 2022. For each MRI, coronal T2-weighted single shot fast spin echo and axial T2-weighted fat-saturated images were independently reviewed by three pediatric radiologists who recorded ovary visualization and ovarian linear measurements (3 planes). Ovarian volumes were calculated from linear measurements. Agreement among observers was calculated using kappa statistics and intraclass correlation coefficients. RESULTS: A total of 181 MRIs were reviewed. The left ovary was visualized in 166-176 (92-97%) cases (R1-R3) and the right ovary was visualized in 165-174 (91-96%) cases with excellent agreement among reviewers (left: K = 0.89 [0.84-0.94], right: K = 0.85 [0.79-0.91]). Interrater class coefficient (ICC) for largest single dimension of the ovary was left: 0.83 (CI 0.79-0.87) and right: 0.85 (CI 0.81-0.89). There were significant moderate to strong correlations between ovarian volume and age (left: 0.67 [0.58-0.75], right: 0.66 [0.57-0.74]). CONCLUSION: The ovaries can be adequately visualized and measured on MRI with excellent inter-reader agreement. This study serves as the foundation for developing normative values for ovarian volumes by age on MRI.

MRI and Blood-based Biomarkers Are Associated With Surgery in Children and Adults With Ileal Crohn's Disease.

BACKGROUND: Despite advances in medical therapy, many children and adults with ileal Crohn's disease (CD) progress to fibrostenosis requiring surgery. We aimed to identify MRI and circulating biomarkers associated with the need for surgical management. METHODS: This prospective, multicenter study included pediatric and adult CD cases undergoing ileal resection and CD controls receiving medical therapy. Noncontrast research MRI examinations measured bowel wall 3-dimensional magnetization transfer ratio normalized to skeletal muscle (normalized 3D MTR), modified Look-Locker inversion recovery (MOLLI) T1 relaxation, intravoxel incoherent motion (IVIM) diffusion-weighted imaging metrics, and the simplified magnetic resonance index of activity (sMaRIA). Circulating biomarkers were measured on the same day as the research MRI and included CD64, extracellular matrix protein 1 (ECM1), and granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies (Ab). Associations between MRI and circulating biomarkers and need for ileal resection were tested using univariate and multivariable LASSO regression. RESULTS: Our study sample included 50 patients with CD undergoing ileal resection and 83 patients with CD receiving medical therapy; mean participant age was 23.9 ±â€…13.1 years. Disease duration and treatment exposures did not vary between the groups. Univariate biomarker associations with ileal resection included log GM-CSF Ab (odds ratio [OR], 2.87; P = .0009), normalized 3D MTR (OR, 1.05; P = .002), log MOLLI T1 (OR, 0.01; P = .02), log IVIM perfusion fraction (f; OR, 0.38; P = .04), and IVIM apparent diffusion coefficient (ADC; OR, 0.3; P = .001). The multivariable model for surgery based upon corrected Akaike information criterion included age (OR, 1.03; P = .29), BMI (OR, 0.91; P = .09), log GM-CSF Ab (OR, 3.37; P = .01), normalized 3D MTR (OR, 1.07; P = .007), sMaRIA (OR, 1.14; P = .61), luminal narrowing (OR, 10.19; P = .003), log C-reactive protein (normalized; OR, 2.75; P = .10), and hematocrit (OR, 0.90; P = .13). CONCLUSION: After accounting for clinical and MRI measures of severity, normalized 3D MTR and GM-CSF Ab are associated with the need for surgery in ileal CD.

Despite advances in medical therapy, many patients with ileal Crohn's disease progress to fibrostenosis requiring surgery. Our study has shown that GM-CSF autoantibodies and MRI biomarker sequences are associated with the need for ileal resection and may help guide management decisions.