title: Comparison of thallium-201 and technetium-99m methoxyisobutyl isonitrile.
abstract: Thallium-201 (201Tl) is a well-established radionuclide used in myocardial perfusion imaging for assessing the presence and prognostic significance of coronary artery disease. Recently, technetium-99m hexakis-2-methoxyisobutyl isonitrile (99mTc-sestamibi) has become available for the same diagnostic and prognostic procedures. This discussion compares the imaging characteristics and clinical applications of 201Tl with those of 99mTc-sestamibi. There is a strong diagnostic concordance between the 2 agents in symptomatic patients. Various comparative clinical trials have shown in numerous patients that both agents have a similar diagnostic yield in both planar and single-photon emission computed tomography (SPECT) imaging. Because of better image quality of the 99mTc agent, there is a trend toward better specificity and normalcy rate, in comparison to 201Tl. However, when using reinjection imaging protocols, 201Tl retains a unique place as an imaging agent to identify viable myocardium.
authors.affiliation: Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut 06510.
authors.forename: F J
authors.initials: FJ
authors.lastname: Wackers
mesh_terms: D003327:Coronary Disease / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D006801:Humans; D011379:Prognosis; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D013794:Thallium Radioisotopes; D017256:Technetium Tc 99m Sestamibi