THE NONCARDIAC DISTRIBUTION OF TC-99M-METHOXY-ISOBUTYL-ISONITRILE (SESTAMIBI) IN NORMAL BEAGLES

Technetium-99m methoxy-isobutyl-isonitrile (sestamibi) is a radiopharm aceutical used for the evaluation of myocardial perfusion, Increased u ptake of sestamibi has also been documented in tumors, The objective o f this study was to document the extracardiac biodistribution of Tc-99 m sestamibi in the normal dog, Nine normal beagles were given 0.35 mCi /kg Tc-99m sestamibi intravenously, and 60 second images were made of the entire body at 1 hour post injection, A defined distribution patte rn was recognized, with good visualization of the heart, liver, gallbl adder, small intestine, kidneys, urinary bladder, popliteal lymph node s, parotid salivary glands and zygomatic salivary glands, Splenic upta ke was not seen, Target to background ratios were calculated for all t he regions listed, using background regions-of-interest with the small est coefficient of variance for the denominator, The mean, range and s tandard deviation of these ratios are given.