title: [Minimal redistribution of thallium-201 representing reversible ischemia after coronary bypass surgery: value of quantitative analysis of exercise thallium-201 SPECT].
abstract: We previously reported the value of minimal redistribution (MR) of thallium-201 in analyzing quantitative polar map analysis (QNT) which correlated well with metabolic activity on FDG-PET. To determine whether ischemic areas that have redistribution are truly reversible, we performed stress and 3-hr delayed thallium-201 SPECT imaging and radionuclide ventriculography (RNV) in 41 patients with coronary artery disease before and after coronary bypass surgery (CABG). Redistribution (RD) was categorized into 4 grades: complete RD (CR), incomplete RD (IR), MR and persistent defect (PD). MR was defined as the segment that showed > or = 2SD improvement in more than 1/3 of the area on QNT, but RD was not evident by visual analysis. 1. QNT identified MR in 30 of 56 segments (54%) where PD is noted by visual inspection. 2. The MR segments showed severer wall motion abnormality (wall motion score: 1.83 +/- 1.12) than did the IR or CR segments (0.99 +/- 1.04) (p < 0.01), but the wall motion was well preserved, compared to the PD segments (2.54 +/- 0.90) (p < 0.01). 3. The grade of RD was compared with improvement in regional perfusion and wall motion on RNV after CABG. Improvement in perfusion was observed in 62 of 77 IR or CR segments (81%) and in 17 of 30 MR segments (57%), but in only 3 of 26 PD segments (12%) (p < 0.01). 4. Similarly, improvement in wall motion was observed in 45 of 57 IR or CR segments (79%) and in 22 of 27 MR segments (81%), but in only 5 of 25 PD segments (20%) (p < 0.01). Thus, the MR segments should be considered reversible after CABG. We conclude that QNT of RD should be performed to detect RD which is slight, yet suggestive of viability.
authors.affiliation: Department of Radiology and Nuclear Medicine, Kyoto University Faculty of Medicine.
authors.forename: H
authors.initials: H
authors.lastname: Ohtani
authors.forename: N
authors.initials: N
authors.lastname: Tamaki
authors.forename: I H
authors.initials: IH
authors.lastname: Mohiuddin
authors.forename: Y
authors.initials: Y
authors.lastname: Yonekura
authors.forename: J
authors.initials: J
authors.lastname: Konishi
authors.forename: K
authors.initials: K
authors.lastname: Hirata
authors.forename: T
authors.initials: T
authors.lastname: Ban
mesh_terms: D000368:Aged; D001026:Coronary Artery Bypass; D003326:Coronary Circulation; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D015635:Radionuclide Ventriculography; D013794:Thallium Radioisotopes; D014022:Tissue Survival; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D013794:Thallium Radioisotopes