title: 3D iteratively reconstructed spatial resolution map and sensitivity characterization of a dedicated cardiac SPECT camera.
abstract: BACKGROUND
  A solid-state cadmium zinc telluride (CZT) SPECT device provides ultrafast myocardial perfusion imaging (MPI) with a spherical field-of-view (FOV). This study aims at determining the spatial resolution and sensitivity throughout this FOV as a guide for patient positioning.
  
  
  RESULTS
  For this CZT camera (Discovery 570c, GE Healthcare), the iteratively reconstructed spatial resolution along 3 Cartesian axes was compared (average resolution 6.9 ± 1.0 mm full-width at half-maximum) using a 2 dimensional array of point sources in air which was aligned with a transverse plane shifted throughout the FOV. Sensitivity was plotted in the central transverse slice and axially in locations comparable to the placement of the heart in 266 rest/stress cardiac studies (M 78, age 63 ± 13 years). The average sensitivity was 0.46 ± 0.19 kc/s/MBq with a transverse gradient of 0.039 ± 0.001 kc/s/MBq/cm (8.9% of the sensitivity per cm). Reconstructed relative activity was uniform (uniformity <9%) and count rate was linear (R = 0.999) over 3 orders of magnitude.
  
  
  CONCLUSIONS
  The CZT SPECT camera offers good resolution, sensitivity, and uniformity, and provides linearity in count rate. A gradient of >8%/cm in sensitivity justifies the crucial role of patient positioning with the heart closest to the detector.
authors.affiliation: Department of Nuclear Medicine, Rambam Health Care Campus, P.O. Box 9602, 31096, Haifa, Israel, j_kennedy@rambam.health.gov.il.
authors.forename: John A
authors.initials: JA
authors.lastname: Kennedy
authors.forename: Ora
authors.initials: O
authors.lastname: Israel
authors.forename: Alex
authors.initials: A
authors.lastname: Frenkel
mesh_terms: D000465:Algorithms; D002104:Cadmium / Q000528:radiation effects*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D055414:Myocardial Perfusion Imaging / Q000295:instrumentation*; D010363:Pattern Recognition, Automated / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013691:Tellurium / Q000528:radiation effects*; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation*; D015032:Zinc / Q000528:radiation effects*
chemical_list: C474490:CdZnTe; D002104:Cadmium; D015032:Zinc; D013691:Tellurium