The Journal of Bone and Joint Surgery, Vol 63, Issue 2 295-305, Copyright © 1981 by Journal of Bone and Joint Surgery, Inc
Quantitative regional blood-flow analysis and its clinical application during routine bone-scanning
SD Deutsch, EJ Gandsman and SC Spraragen
A method of combined dynamic and static bone-imaging using technetium
99-labeled phosphonate is described. During the dynamic part of the study,
immediately after intravenous injection of the radionuclide, counts per
second were recorded over a period of time for analogous regions of normal
and diseased bones. The counts per second then were plotted against time to
give time-activity curves for each of these regions. The time-activity
curves were divided into arterial, venous, and blood-pool phases. Each
phase was integrated and then divided by the time-span of the phase to give
average total counts per unit of time. The values of these normalized
integrals were directly proportional to the blood flow to the regions of
bone from which they were calculated. Ratios of normalized integrals from
the analogous regions of the diseased bone to the normal bone were
calculated to determine whether the blood flow to the diseased bone was
decreased or increased. Static images of the bone structures analyzed
during the dynamic portion of the study were obtained two hours after the
initial injection of the radionuclide and the total number of counts for
analogous regions on the static images of the normal and diseased bones
were static images of the normal and diseased bones were recorded. The
total number of counts for each region was divided by the area of that
region to give average total counts. Ratios of the normalized counts were
calculated for analogous regions of the diseased to the normal bone to
determine whether there was an increase or decrease in concentration of the
radionuclide. The method first was used to evaluate hip pain in children
and adults. In order to recognize an abnormal result, mean values and two
standard deviations were calculated for the dynamic and static ratios in a
group of fifty patients who had no clinical complaints about the hips or
lower extremities. Any ratios outside of the range of two standard
deviations were considered abnormal. The method later was used to evaluate
other bones, such as the tibia and humerus. Any value for the ratios beyond
1 +/- 0.20 was considered abnormal for these studies.