The application of Contrast-enhanced US in distinguishing adrenal neuroblastoma from adrenal hemorrhage in infants

Background Neuroblastoma and hemorrhage are the two most frequently occurred in adrenal region in infants. However, their characterization and differentiation is challenging on baseline ultrasound (BUS). As an increasingly sophisticated tool, contrast-enhanced US(CEUS) is proposed for differentiating such lesions. Objectives To investigate the usefulness of CEUS in the differentiation of adrenal neuroblastoma and adrenal hemorrhage (AH) in infants less than 6 months old. Materials and Methods The imaging and medical records of 20 infants with adrenal lesions (including 11 neuroblastoma and AH in 9) were retrospectively reviewed. Four readers(two resident and two attending doctors) independently reviewed the images and the diagnostic performances were evaluated by receiver operating characteristic (ROC) analysis. The interobserver agreement was evaluated with κ value. Results There had differences between them on BUS and CEUS (all p < 0.05). CEUS yielded a sensitivity of 100% (95% CI 0.571–0.995), specificity of 100% (95% CI 0.402–0.961), higher than BUS (sensitivity 81.8%, specificity 66.9%). The diagnostic performance of one resident and both attending doctors in terms of the area under the ROC curve (0.712 vs 0.995, 0.561 vs 0.884, and 0.621 vs 0.958, respectively), specificity and positive predictive value improved and sensitivity, negative predictive of all readers improved after CEUS (all p < 0.05). Indeterminate lesions reduced significantly (35.0% vs 25.0% in residents doctors, 25.0% vs 10.0% in attending physicians). The interobserver agreement increased from κ = 0.550 to κ = 0.824 after CEUS. Conclusion The diagnostic performance of CEUS in the differentiation of adrenal neuroblastoma from AH might be greatly improved compared with BUS.