Black Bone MRI vs. CT in temporal bone assessment in craniosynostosis: a radiation-free alternative

Background and purpose: Craniosynostoses are rare congenital craniofacial malformations, variably affected by hearing loss, often requiring repeated CT examinations to assess skull or temporal bone (TB) abnormalities. In order to avoid radiation exposure in these young patients, efforts are made to assess the skull abnormalities on MR bone imaging sequences, such as Black Bone (BB). Our aim is to compare BB, a radiation-free imaging technique, with CT for the assessment of the TB.

Materials and methods: 48 patients who underwent both BB and CT (2016-2021) in Sophia Children's Hospital, Erasmus MC, Rotterdam, were retrospectively investigated. BB and CT (the diagnostic gold standard for imaging the temporal bone) were evaluated blindly and independently by 3 observers; visibility and abnormalities of TB structures and cranial nerves were scored; abnormal findings were confirmed by a senior pediatric neuroradiologist. The statistical analysis was performed using Gwet's AC1 agreement and modified versions of the Wilcoxon signed-rank test and sign test with a Bonferroni-Holm correction (p < 0.05).

Results: CT was rated higher than BB in structure visibility (global p = 0.0002), but was rated similar to BB when assessing TB anatomy and pathology (global p = 0.58). The visibility ratings showed better interobserver agreement values on CT than BB. In the normal/abnormal ratings, both BB (0.75-1) and CT (0.88-1) showed high interobserver agreement values.

Conclusion: Our preliminary results suggest that BB is a promising tool for screening TB pathology in patients with craniosynostosis who require MR imaging.