Experimental study of measurement of regional bone blood flow in the adult mongrel dog using radioactive microspheres.

To date, no one has conclusively accurately measured the regional bone blood flow mainly due to the lack of a proper investigative method. In this study, regional blood flow in the femur and tibia in adult mongrel dogs were studied using 85Sr-and 141Ce-labeled microspheres with a diameter of 15 +/- 5 microns. The blood flow rates were calculated by relating the radioactivity from tissue samples that from sample blood with a known flow. The highest rate of blood flow, 48.7 ml/min/100 g, was found in the femoral marrow and the lowest, 3.0 ml/min/100 g, in the diaphyseal cortex of the tibia. Flow rates in the metaphyseal regions, about 15 or 20 ml/min/100 g, were one and a half or 2 times greater than those in the epiphyseal regions. These values were mostly within the range of values reported by other investigators. Radioactive microspheres can be applied not only to physiological conditions but also to various pathological conditions if their size and the dose, the site and method of injection and tissue sampling are investigated further.