title: Quantitative planar imaging with technetium-99m methoxyisobutyl isonitrile: comparison of uptake patterns with thallium-201.
abstract: To compare the myocardial uptake pattern of 99mTc-labeled methoxyisobutyl isonitrile [( 99mTc] MIBI) and 201TI, planar scintigraphy were performed in both patients with documented coronary artery disease and subjects with a low likelihood of disease. Quantitative analysis was employed using a standard interpolative background subtraction algorithm and a new algorithm modified to better accommodate for the differences in extracardiac activity seen with [99mTc]MIBI rest images. Among patients with coronary artery disease, the standard algorithm yielded no significant difference in relative defect magnitude between [99mTc]MIBI and 201TI on stress scintigrams (p = 0.48), although the magnitude of [99mTc]MIBI defects was greater on resting images (p = 0.02). When the modified algorithm was employed, defect magnitude was similar for both stress (p = 0.91) and rest (p = 0.20) images. Normal segmental uptake ratios derived from a comparison of contralateral segments (e.g., septal:posterolateral) in the low likelihood patients were similar for both [99mTc]MIBI and 201TI. Thus, modification of the standard interpolative background subtraction algorithm is necessary for quantitative planar [99mTc]MIBI perfusion imaging. When appropriate background subtraction is employed, myocardial uptake and quantitative defect magnitude of [99mTc]MIBI and 201TI planar images are similar.
authors.affiliation: Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville 22908.
authors.forename: A J
authors.initials: AJ
authors.lastname: Sinusas
authors.forename: G A
authors.initials: GA
authors.lastname: Beller
authors.forename: W H
authors.initials: WH
authors.lastname: Smith
authors.forename: E L
authors.initials: EL
authors.lastname: Vinson
authors.forename: V
authors.initials: V
authors.lastname: Brookeman
authors.forename: D D
authors.initials: DD
authors.lastname: Watson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009570:Nitriles; D009942:Organometallic Compounds; D005082:Physical Exertion; D011877:Radionuclide Imaging; D013382:Subtraction Technique; D013667:Technetium; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes
chemical_list: D009570:Nitriles; D009942:Organometallic Compounds; D013794:Thallium Radioisotopes; D013667:Technetium; D017256:Technetium Tc 99m Sestamibi