title: Rapid back to back adenosine stress/rest technetium-99m teboroxime myocardial perfusion SPECT using a triple-detector camera.
abstract: Technetium-99m-teboroxime is characterized by a high extraction fraction over a wide range of blood flow rates, rapid myocardial clearance and avid hepatic uptake. This study determined the imaging parameters and examined the clinical efficacy of a rapid back to back adenosine stress/rest teboroxime myocardial perfusion SPECT protocol using a triple-detector camera. Acquisition parameters were determined using cardiac phantom studies which were then applied in SPECT studies of 51 catheterized patients (22 with prior myocardial infarction) and 20 patients with a "low" (7.9% +/- 4.3%) likelihood of coronary artery disease. Technetium-99m-teboroxime (20-25 mCi) was injected at the third minute of adenosine infusion. Teboroxime (20-25 mCi) was also injected at rest, 15 min later. Stress followed by rest SPECT were completed within 25 min using a triple-detector camera and sequential, 1-min continuous rotations in alternating directions. Summed raw data from the first to second (1-2 min), second to third (2-3 min) and second to fifth (2-5 min) minutes of imaging following stress teboroxime injection were reconstructed and compared for image quality, degree of liver interference, and accuracy for diagnostic efficacy. In a subgroup of 30 patients, 2-8-min summed images were also reconstructed to compare this more conventional imaging protocol with our rapid acquisition. Image quality was fair to good in 75% of the 1-2-min, 84% of the 2-3-min and 2-5-min studies and 53% of the 2-8-min scans. The frequency of severe liver interference appeared to increase with the duration of imaging time (1-2 min: 3%; 2-3 min: 7%; 2-5 min: 8%) and was greatest (30%, p = 0.08) with 2-8-min images. Three patients (4%) had uninterpretable studies due to intense hepatic uptake. Overall sensitivity (95%) and specificity (71%) were equal for the 2-3-min and 2-5-min stress images and appeared better than in the 1-2-min images (84% and 57%, respectively). For the 2-8-min scans, vessel sensitivity (69%) and specificity (63%) appeared poorer than with 2-3-min studies (83% and 81%, respectively). Normalcy rates were 89% for the 2-3-min and 2-5-min and 79% for 1-2-min images. The back to back adenosine stress/rest teboroxime SPECT can be performed in 30 min using a triple-detector camera. Although overall high sensitivity and normalcy rates were achieved, the protocol is technically demanding. Interference due to intense liver uptake remains problematic.
authors.affiliation: Dept. of Imaging, Cedars-Sinai Medical Center, Los Angeles, CA 90048.
authors.forename: T
authors.initials: T
authors.lastname: Chua
authors.forename: H
authors.initials: H
authors.lastname: Kiat
authors.forename: G
authors.initials: G
authors.lastname: Germano
authors.forename: K
authors.initials: K
authors.lastname: Takemoto
authors.forename: G
authors.initials: G
authors.lastname: Fernandez
authors.forename: Y
authors.initials: Y
authors.lastname: Biasio
authors.forename: J
authors.initials: J
authors.lastname: Friedman
authors.forename: D
authors.initials: D
authors.lastname: Berman
mesh_terms: D000241:Adenosine; D000368:Aged; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008099:Liver / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D008961:Models, Structural; D015609:Organotechnetium Compounds; D010091:Oximes; D012680:Sensitivity and Specificity; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation / Q000379:methods*
chemical_list: D015609:Organotechnetium Compounds; D010091:Oximes; D000241:Adenosine; C060156:technetium Tc 99m teboroxime