QUANTITATIVE CT IN THE MEASUREMENT OF BONE QUANTITY AND BONE QUALITY FOR ASSESSING OSTEOPOROSIS

The biomechanical strength of the skeleton, and hence the risk of futu re fractures, depends on both the bone quantity (assessed in terms of bone mineral density) and Done quality (assessed in terms of the integ rity of its internal architecture). Precise methods of measuring the c alcium-equivalent density of both the trabecular and cortical componen ts of vertebral bone using quantitative computed tomography are presen ted. For a group of Post-menopausal Kuwaiti females, we have shown tha t the trabecular and cortical components are highly correlated with ea ch other at both the L3 and L4 lumbar vertebral levels, with correlati on coefficients of 0.78 and 0.74 (P < 0.0001) respectively. We have ex plored the anisotropic distribution of trabecular bone arid considered the use of the standard deviation and the coefficient of variation of trabecular CT numbers as texture Indicators and surrogate measures of bone quality. The coefficient of variation was the better texture ind icator: used with bone mineral density values it successfully discrimi nated between two classes of patients (those with fractures and those without) with high sensitivity (greater than or equal to 89%) and spec ificity (greater than or equal to 82%). Copyright (C) 1996 Elsevier Sc ience Ltd for IPEMB.