CONNECTIVITY IN HUMAN CANCELLOUS BONE BY 3-DIMENSIONAL MAGNETIC-RESONANCE MICROSCOPY

Bone architecture affects strength and resistance to fracture. Trabecu lar connectivity is now recognized as an important measure of bone qua lity, and could be useful as an indicator of the osteoporotic conditio n, as well as a tool for measuring the effectiveness of therapies. We have applied three-dimensional magnetic resonance imagine microscopy t o human cancellous bone biopsies, and report the results of connectivi ty measurements. Sample heterogeneity was examined on the basis of con nectivity density for subvolumes. The choice of examination volume had a significant effect on connectivity density measurements, but sample volumes greater than 100 mm(3) were found to give stable results. Con nectivity density was strongly correlated with nodal density, and two- dimensional estimates of connectivity, but not bone volume fraction. R epeat measurement at constant resolution (69x138x109 mu m, signal-to-n oise ratio of about 35) showed reproducibility of about 5% for connect ivity density. Our most recent results have significantly enhanced res olution (69x69x43 mu m); bone fraction remained constant, but apparent connectivity density is greater. (C) 1997 American Association of Phy sicists in Medicine.