Quantitative computation of induced heterotopic bone formation by an image analysis system.

The formation of heterotopic bone (HO) is an unsolved problem and occurs in response to a variety of conditions including muscle contusions, injuries, surgical procedures, and burns. A sensitive method for quantification of HO would be valuable for experimental work and research on bone morphogenetic protein (BMP). The hardware and software used in an image analysis system are presented. This system provides a rapid and highly accurate method for determining the amount of HO in a muscle. Using the mouse thigh pouch as an experimental system, this method demonstrated that quantities of new bone were formed in direct proportion to the amount of BMP/NCP implanted. This system can be used for measuring HO on roentgenograms or any other image, including computed tomographic (CT) scans, magnetic resonance imaging (MRI), and autoradiograms.