PNNL

Abstract

We present an atlas-based deformable registration method for bones segmented from quantitative computed tomography (QCT) scans, with the goal of mapping their interior bone mineral densities (BMDs) volumetrically. The technical contributions include a new type of subdivisionbased anatomical atlases (subdivision-embedded atlases), and an efficient and fully automated pipeline for registering atlases of 12 tarsal and metatarsal bones to a segmented QCT scan of a human foot. Our evaluation shows that the subdivision-embedded atlases result in more accurate fitting of the boundary surface of the target bone than previous atlases based on the subdivision technique. Moreover, the mapping of BMD enabled by the registration is consistent for bones in repeated scans, and the regional BMD automatically computed from the mapping is not significantly different from expert annotations. The results suggest that our improved subdivision-based registration method is a reliable, efficient way to replace manual labor for measuring regional BMD in foot bones in QCT scans.