Selective uptake of 99mTc complexes and 67Ga in acutely infarcted myocardium.
The suitability of various radiopharmaceuticals (99mTc-tetracycline analogs, 99mTc-glucoheptonate, 99mTc-diphosphonate, and 67Ga-citrate) for use in imaging acute myocardial infarction was assessed by determining their biologic distributions in experimentally infarcted dogs. The highest infarct-to-normal myocardial concentration ratio was found with 99mTc-diphosphonate (27.9:1); the highest infarct-to-liver ratio was also found with 99mTc-diphosphonate (15.9:1). The infarct-to-bone ratio, however, was 0.4:1 with 99mTc-diphosphonate. There was an excellent positive linear correlation between blood-flow reduction and uptake of the radiopharmaceutical after a threshold reduction in blood flow with 99mTc-glucoheptonate and 99mTc-tetracycline. Technetium-99m-tetracycline accumulated only in infarcted tissue while 99mTc-diphosphonate was increased in both ischemic and infarcted tissue. Thus, 99mTc-diphosphonate has characteristics best suited for scintigraphic imaging. Since 99mTc-tetracycline accumulates only in infarcted tissue, however, this tracer more accurately defines the size of an acute infarction.
D000818:Animals; D002751:Chlortetracycline; D004285:Dogs; D005710:Gallium Radioisotopes; D006539:Heptoses; D009203:Myocardial Infarction / Q000175:diagnosis*; D009943:Organophosphorus Compounds; D010118:Oxytetracycline; D011877:Radionuclide Imaging; D013400:Sugar Acids; D013667:Technetium; D013754:Tetracyclines
D005710:Gallium Radioisotopes; D006539:Heptoses; D009943:Organophosphorus Compounds; D013400:Sugar Acids; D013754:Tetracyclines; D013667:Technetium; D002751:Chlortetracycline; D010118:Oxytetracycline