Evaluation of equine scintigraphic bone scans is carried out mostly by visu
al interpretation. By the use of ROI (regions of interest)-technique scinti
graphic stifle scans were evaluated regarding possible significant differen
ces between clinically healthy and pathological stifles. Certain regions of
interest were measured quantitatively trying to determine reference ranges
for the different regions. 207 stifles of 195 horses were examined and cla
ssified into three groups according to the clinical symptoms. For the quant
itative evaluation of the lateral views 13 different regions of interest we
re appointed. One of these regions was located on the diaphysis of the tibi
a and served as reference region. Most of the ratios between the other regi
ons and this reference region of the clinically healthy group show a strong
dependence on age of the hones, decrease quickly until 5 years of age and
then find their level. Significant differences between the clinically healt
hy and pathological stifles were found for 8 of the 12 regions. The results
prove that the quantitative evaluation of stifle scintigraphy in horses ca
nnot replace the visual examination of the scintigram. The scintigraphic ex
amination is the only diagnostic procedure that gives early information abo
ut actual bone metabolism, but is too sensitive for providing useful refere
nce ranges for the quantitative evaluation.