Metabolic activity in the areas of new fill-in after thallium-201 reinjection: comparison with positron emission tomography using fluorine-18-deoxyglucose.
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.
Tamaki
N
N
Department of Radiology and Nuclear Medicine, Kyoto University Faculty of Medicine, Japan.
Ohtani
H
H
Yamashita
K
K
Magata
Y
Y
Yonekura
Y
Y
Nohara
R
R
Kambara
H
H
Kawai
C
C
Hirata
K
K
Ban
T
T
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
D005462:Fluorine Radioisotopes; D013794:Thallium Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose