Combined IVIM and DCE-MRI for early prediction of avascular necrosis after closed reduction in developmental dysplasia of the hip: a pilot study

This study aimed to evaluate the diagnostic performance of quantitative perfusion MRI biomarkers derived from intravoxel incoherent motion and dynamic contrast-enhanced MRI for predicting avascular necrosis development after closed reduction in developmental dysplasia of the hip. This pilot study included 16 children with 32 hips who underwent closed reduction for developmental dysplasia of the hip. All patients received both DCE-MRI and IVIM examinations within 6 h post-reduction using a 3T MRI scanner. Quantitative parameters from IVIM and DCE-MRI were measured in femoral head epiphyses by two independent readers. Inter-reader reproducibility was assessed using intraclass correlation coefficients. Avascular necrosis was assessed on radiographs at 6, 12, and 18 months using the Bucholz-Ogden classification. Given the small sample size, Firth’s penalized logistic regression was used for prediction modeling with bootstrap internal validation. Twelve of 32 hips (37.5%) developed avascular necrosis during follow-up. Inter-reader reproducibility was excellent for all parameters (ICC 0.817–0.996). Hips developing avascular necrosis showed significantly lower ADC fast and K trans compared to non-avascular necrosis hips. The combined ADC fast +K trans model achieved an apparent AUC of 0.963 (95% CI: 0.904-1.000), with 100% sensitivity and 90% specificity. Bootstrap-corrected AUC was 0.952. Quantitative perfusion biomarkers from IVIM and DCE-MRI obtained immediately post-reduction show strong discriminative ability for AVN prediction in this pilot cohort. Prospective multicenter validation is warranted before clinical implementation.