TY - JOUR T1 - Comparative <sup>18</sup>F-FDG PET of Experimental <em>Staphylococcus aureus</em> Osteomyelitis and Normal Bone Healing JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1406 LP - 1411 VL - 45 IS - 8 AU - Jyri K. Koort AU - Tatu J. Mäkinen AU - Juhani Knuuti AU - Jari Jalava AU - Hannu T. Aro Y1 - 2004/08/01 UR - http://jnm.snmjournals.org/content/45/8/1406.abstract N2 - PET using 18F-FDG is a promising imaging modality for bone infections, based on intensive consumption of glucose by mononuclear cells and granulocytes. The method may have limitations in distinguishing uncomplicated bone healing from osteomyelitis. Bone healing involves an inflammatory phase that represents a highly activated state of cell metabolism and glucose consumption, mimicking infection on PET images. This laboratory study of a standardized model was designed to compare the 18F-FDG PET characteristics of normal bone healing with those of local osteomyelitis. Methods: A localized osteomyelitis model of the rabbit tibia was created by modifying a previously reported canine model. In the osteomyelitic group (n = 8), a standardized metaphyseal defect of the proximal right tibia was surgically created and filled with a block of orthopedic bone cement, followed by injection of a predetermined amount (0.1 mL) of Staphylococcus aureus (strain 52/52A/80, 1 × 105/mL) into the space around the cement. The control group of animals with normal bone healing (n = 8) underwent the same procedure, but the bacterial injection was replaced by a sterile saline injection. The bone cement was surgically removed during debridement at 2 wk. Osteomyelitis was confirmed with positive bacterial cultures during the debridement and 6 wk later at the time of sacrifice. 18F-FDG PET and peripheral quantitative CT were performed 3 and 6 wk after the debridement. The presence of osteomyelitic bone changes on plain radiographs was classified according to a previously published system. Results: Before surgery, the standardized uptake values of 18F-FDG did not differ markedly between the right and left tibias. In the control animals, uncomplicated bone healing was associated with a temporary increase in 18F-FDG uptake at 3 wk (P = 0.007), but it returned almost to normal by 6 wk. In the experimental animals, localized osteomyelitis resulted in an intense continuous uptake of 18F-FDG, which was higher than that of healing and intact bones at 3 wk (P = 0.014 and P &lt; 0.001, respectively) and at 6 wk (P &lt; 0.001). Conclusion: 18F-FDG PET seems to be an efficient tool in the differentiation of uneventful bone healing from bone healing complicated by localized osteomyelitis. ER -