title: Inhomogeneity of gated and ungated SPECT technetium-99m-sestamibi bull's-eyes in normal dogs: comparison with thallium-201.
abstract: By computer simulation, we have previously hypothesized, independent of the isotope imaged, that differences in view-to-view resolution and attenuation patterns predictably cause count density distortions in SPECT images. We tested the simulation predictions for both ECG-gated and ungated SPECT 99mTc-sestamibi and SPECT 201Tl myocardial perfusion images in normal dogs. In agreement with the predictions of the computer model, distortions in SPECT 99mTc-sestamibi myocardial perfusion images are virtually equivalent to SPECT 201Tl, dependent on the exact SPECT acquisition orbit and markedly different for a posterior 180 degrees acquisition arc compared to an anterior 180 degrees acquisition arc. Furthermore, ungated and gated SPECT 99mTc-sestamibi images show similar count inhomogeneities. These results suggest that little is to be gained from a 360 degrees acquisition with SPECT 99mTc-sestamibi, and that image distortions from gated or ungated SPECT 99mTc images with 180 degrees orbits will be similar to those in SPECT 201Tl images.
authors.affiliation: Carlyle Fraser Heart Center, Crawford Long Hospital, Emory University, Department of Nuclear Cardiology, Atlanta, GA 30365.
authors.forename: R L
authors.initials: RL
authors.lastname: Eisner
authors.forename: S E
authors.initials: SE
authors.lastname: Martin
authors.forename: A R
authors.initials: AR
authors.lastname: Leon
authors.forename: L S
authors.initials: LS
authors.lastname: Schmarkey
authors.forename: M A
authors.initials: MA
authors.lastname: Worthy
authors.forename: T H
authors.initials: TH
authors.lastname: Chu
authors.forename: R E
authors.initials: RE
authors.lastname: Patterson
mesh_terms: D000241:Adenosine / Q000008:administration & dosage; D000818:Animals; D003198:Computer Simulation; D004285:Dogs; D004562:Electrocardiography; D006321:Heart / Q000000981:diagnostic imaging*; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D013794:Thallium Radioisotopes; D017256:Technetium Tc 99m Sestamibi; D000241:Adenosine