title: Metabolic activity in the areas of new fill-in after thallium-201 reinjection: comparison with positron emission tomography using fluorine-18-deoxyglucose.
abstract: Reinjection of thallium-201 after recording the 3-hr delayed scan often demonstrates improvement in areas of persistent abnormalities. To determine the metabolic activity of these areas, the changes seen on stress/redistribution/reinjection thallium SPECT were compared with PET using fluorine-18-fluorodeoxyglucose (FDG) in 18 patients with coronary artery disease. Of 48 segments showing no redistribution on the delayed scan, the reinjection scan identified new fill-in in 20 segments (42%), all of which demonstrated FDG uptake. In contrast, only 7 of the 28 segments (25%) showing no fill-in after reinjection were PET viable (p less than 0.01). Eleven patients had coronary bypass graft surgery after the radionuclide study. The majority of the segments showing redistribution (87%) and new fill-in after reinjection (65%) improved in wall motion, whereas only eight segments (25%) without new fill-in improved after surgery. Of those without new fill-in, two segments showing PET ischemia improved in wall motion, whereas the remaining six segments showing PET scar did not improve after surgery. Thus, the segments showing new fill-in after reinjection are PET viable myocardium. However, reinjection thallium imaging still underestimates the extent of tissue viability compared to PET imaging.
authors.affiliation: Department of Radiology and Nuclear Medicine, Kyoto University Faculty of Medicine, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Tamaki
authors.forename: H
authors.initials: H
authors.lastname: Ohtani
authors.forename: K
authors.initials: K
authors.lastname: Yamashita
authors.forename: Y
authors.initials: Y
authors.lastname: Magata
authors.forename: Y
authors.initials: Y
authors.lastname: Yonekura
authors.forename: R
authors.initials: R
authors.lastname: Nohara
authors.forename: H
authors.initials: H
authors.lastname: Kambara
authors.forename: C
authors.initials: C
authors.lastname: Kawai
authors.forename: K
authors.initials: K
authors.lastname: Hirata
authors.forename: T
authors.initials: T
authors.lastname: Ban
mesh_terms: D003326:Coronary Circulation / Q000502:physiology; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003847:Deoxyglucose / Q000031:analogs & derivatives*; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D009206:Myocardium / Q000378:metabolism*; D013794:Thallium Radioisotopes / Q000008:administration & dosage; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D005462:Fluorine Radioisotopes; D013794:Thallium Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose