title: Myocardial perfusion imaging with a new radiotracer, technetium-99m-hexamibi (methoxy isobutyl isonitrile): comparison with thallium-201 imaging.
abstract: Technetium-99m-hexamibi (methoxy isobutyl isonitrile) is a Tc-99m-hexakis analog that can be used as a myocardial perfusion imaging agent. This is a report of an initial study that was performed in four institutions to assess the feasibility of Tc-99m-hexamibi myocardial imaging for the detection of coronary artery disease in patients undergoing treadmill stress test. Thirty-three patients referred for evaluation of chest pain had two exercise stress tests, one with Tl-201 and at least 24 hours after, and a second one with Tc-99m-hexamibi. Myocardial planar imaging started 60 minutes after injection at stress of 10-20 mCi of Tc-99m-hexamibi. Because this agent does not redistribute in myocardium after a stress injection, a second injection of 10-20 mCi of Tc-99m-hexamibi was performed with the patient at rest a few days later. Qualitative assessment of both Tl-201 and Tc-99m-hexamibi myocardial distribution was performed in 297 left ventricle segments (three segments of each of three views). There was a good correlation for the presence of normality, scar, or ischemia with the two radiopharmaceuticals, both on a segment by segment (259/297, or 87.2%) and patient-by-patient basis (29/33, or 87.9%). The number of segments found ischemic with Tl-201 and with Tc-99m-hexamibi were nearly equal, as were the number that were normal with one radiopharmaceutical and ischemic by the other. This initial study demonstrates that it is possible to detect stress-induced abnormalities of myocardial perfusion with Tc-99m-hexamibi similar to Tl-201 imaging.
authors.affiliation: Department of Nuclear Medicine, Hôtel-Dieu de Montréal, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Taillefer
authors.forename: G
authors.initials: G
authors.lastname: Dupras
authors.forename: V
authors.initials: V
authors.lastname: Sporn
authors.forename: P
authors.initials: P
authors.lastname: Rigo
authors.forename: J
authors.initials: J
authors.lastname: Leveille
authors.forename: P
authors.initials: P
authors.lastname: Boucher
authors.forename: N
authors.initials: N
authors.lastname: Perez-Balino
authors.forename: L L
authors.initials: LL
authors.lastname: Camin
authors.forename: K A
authors.initials: KA
authors.lastname: McKusick
mesh_terms: D000328:Adult; D000368:Aged; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D004341:Drug Evaluation; D005080:Exercise Test / Q000379:methods; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009570:Nitriles / Q000493:pharmacokinetics; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D013667:Technetium; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D014018:Tissue Distribution
chemical_list: D009570:Nitriles; D009942:Organometallic Compounds; D013794:Thallium Radioisotopes; D013667:Technetium; D017256:Technetium Tc 99m Sestamibi