Measurement of regional bone and bone marrow blood flow in the rabbit using the hydrogen washout technique

This study tested the feasibility of using the hydrogen washout technique for measuring regional bone and bone marrow blood flow. Washout curves in cancellous and cortical bone were mono-exponential, indicating homogeneous perfusion of these tissues. Epiphyseal cancellous bone blood flow (0.129 +/- 0.015 ml/min/ml) and metaphyseal cancellous bone blood flow (0.170 +/- 0.014 ml/min/ml) were approximately twice as rapid as that of cortical bone (0.069 +/- 0.002 ml/min/ml). Washout of hydrogen from bone marrow was variable and usually formed a bi-exponential pattern, indicating non-homogeneous perfusion. Blood flow rate determined by analyzing the rapid components was 1.04 +/- 0.10 ml/min/ml, and that from the slow components was 0.27 +/- 0.02 ml/min/ml. Our blood flow rates are within the range of values reported by investigators using different methods, and the hydrogen washout technique offers specificity and ease of repetitive determinations not available with other methods.