title: Organ distribution of thallium-201 during intravenous adenosine infusion: comparison with exercise.
abstract: Thallium-201 (Tl-201) distribution during adenosine infusion was assessed quantitatively and compared with that of exercise imaging. Adenosine and exercise Tl-201 single-photon emission computed tomography (SPECT) were performed in 40 patients with suspected coronary artery disease. In the whole-body images (n = 5) and the unprocessed anterior projection images acquired as part of the initial imaging (n = 35), Tl-201 counts in the myocardium were normalized for the injected dose. Total heart counts were higher during adenosine infusion than during exercise (190 +/- 43 counts/MBq vs 145 +/- 31 counts/MBq, p < 0.01). A heart-to-lung count ratio between adenosine infusion and exercise was not different. A heart-to-liver count ratio was lower during adenosine infusion than during exercise (1.3 +/- 0.3 vs 2.3 +/- 0.5, p < 0.01). Regional Tl-201 uptakes at the inferior wall of the left ventricle during adenosine infusion were closely correlated with those uptakes during exercise (r = 0.94, p < 0.01, slope = 0.96). The sensitivity, specificity, and accuracy of adenosine Tl-201 SPECT for the detection of right coronary artery stenosis were comparable with those of exercise imaging. These results indicated that higher Tl-201 uptake in the liver during adenosine than during exercise did not interfere with the interpretation of myocardial images. Tl-201 counts in the myocardium that were larger during adenosine infusion than during exercise reflected a larger increase in coronary blood flow and thus resulted in better image quality.
authors.affiliation: First Department of Internal Medicine, Yamagata University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Takeishi
authors.forename: S
authors.initials: S
authors.lastname: Abe
authors.forename: J
authors.initials: J
authors.lastname: Chiba
authors.forename: A
authors.initials: A
authors.lastname: Komatani
authors.forename: Y
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: H
authors.initials: H
authors.lastname: Tomoike
mesh_terms: D000241:Adenosine / Q000008:administration & dosage*; D000368:Aged; D016009:Chi-Square Distribution; D003327:Coronary Disease / Q000175:diagnosis / Q000453:epidemiology / Q000378:metabolism; D005069:Evaluation Studies as Topic; D005080:Exercise Test / Q000706:statistics & numerical data; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes / Q000493:pharmacokinetics*; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D014915:Whole-Body Counting / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data
chemical_list: D013794:Thallium Radioisotopes; D000241:Adenosine