Studies on focal alveolar bone healing with technetium (Tc)-99m labeled methylene diphosphonate and gold-collimated cadmium telluride probe.
The benefit of using a collimator for a miniaturized cadmium telluride probe was evaluated by monitoring the bone-healing processes for 13 weeks after the induction of small iatrogenic alveolar bone lesions in one side of the mandible in beagles. Technetium (Tc)-99m labeled methylene diphosphonate (200 to 300 MBq, 5.1 to 8.1 mCi, in a solution of 0.5 to 1 ml, intravenously) was used as a bone-seeking radiopharmaceutical. The radioactivity over the bone lesion (L) and the contralateral normal site (C) in the mandible were measured between 1.5 and 2 hours after injection of the tracer, and the activity ratio L/C served as an index of relative bone uptake. A study of six dogs revealed that the healing response to a hemispheric bone defect of 2 mm diameter in the cortical bone could not be detected by an uncollimated probe, and in a repeated study in two dogs the use of a gold collimator (5 mm in diameter, 5 mm in length) did not increase the L/C ratio significantly. A second study in six dogs with 5 mm lesions showed that although systematic trends in the time courses of the L/C ratio obtained both with and without the collimator could be demonstrated, the L/C ratio of collimated versus uncollimated measurements was significantly (p less than 0.005) increased. In three of the latter six dogs, abscesses developed after 9 weeks, leading to a second increase (p less than 0.05) of the L/C ratio with collimation compared with the noninflammation group; without collimation no significant (p greater than 0.15) difference between the two groups could be demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)
Tsuchimochi
M
M
Diagnostic Systems Branch, National Institute of Dental Research, National Institutes of Health, Bethesda.
Hosain
F
F
Engelke
W
W
Zeichner
S J
SJ
Ruttimann
U E
UE
Webber
R L
RL
D000539:Alveolar Process / Q000000981:diagnostic imaging*; D000818:Animals; D001861:Bone Regeneration; D002104:Cadmium; D019187:Cadmium Compounds; D004285:Dogs; D005069:Evaluation Studies as Topic; D005260:Female; D006046:Gold; D011834:Radiation Monitoring / Q000295:instrumentation; D011877:Radionuclide Imaging; D013669:Technetium Tc 99m Medronate; D013691:Tellurium
D019187:Cadmium Compounds; D002104:Cadmium; D006046:Gold; D013691:Tellurium; C028337:cadmium telluride; D013669:Technetium Tc 99m Medronate