Effect of a patient-specific minimum activity in stress myocardial perfusion imaging using CZT-SPECT: Prognostic value, radiation dose, and scan outcome

J Nucl Cardiol. 2018 Feb;25(1):26-35. doi: 10.1007/s12350-017-1011-z. Epub 2017 Aug 18.

Abstract

Background: SPECT Myocardial perfusion imaging (MPI) is associated with a relatively high radiation burden and decreasing image quality in heavy patients. Patient-specific low-activity protocols (PLAPs) are suggested but follow-up data is lacking. Our aim was to compare the use of a standard fixed-activity protocol (FAP) with a PLAP in cadmium zinc telluride (CZT)-SPECT MPI.

Methods: We retrospectively included 1255 consecutive patients who underwent CZT-SPECT stress-optional rest MPI. 668 Patients were scanned using FAP (370 MBq) and 587 patients using PLAP (2.25 MBq·kg-1). Percentage of scans interpreted as normal, radiation dose, and 1-year follow-up including hard event rates (all-cause death or non-fatal myocardial infarction) were collected and compared.

Results: The percentage of scans interpreted as normal was 67% in FAP and 70% in PLAP groups (P = .29). The annualized hard event rates in these patients were 1.0% in the FAP and 0.9% in the PLAP group (P = .86). However, the mean radiation dose decreased by 23% for stress-only and by 15% to 2.6 mSv for stress-optional rest MPI after introduction of the PLAP (p<0.001).

Conclusions: Introduction of a patient-specific low-activity protocol does not affect the percentage of scans interpreted as normal or prognosis but significantly lowers the radiation dose for CZT-SPECT MPI.

Keywords: CdZnTe; High-efficiency camera; Radiation dose reduction; myocardial perfusion imaging: SPECT; stress-only.

MeSH terms

  • Aged
  • Body Weight
  • Cadmium*
  • Coronary Artery Disease / diagnostic imaging
  • Electrocardiography
  • Female
  • Follow-Up Studies
  • Gamma Cameras
  • Humans
  • Male
  • Middle Aged
  • Myocardial Perfusion Imaging*
  • Prognosis
  • Radiation Dosage
  • Radionuclide Imaging
  • Radiopharmaceuticals / pharmacology
  • Retrospective Studies
  • Tellurium*
  • Tomography, Emission-Computed, Single-Photon*
  • Zinc*

Substances

  • CdZnTe
  • Radiopharmaceuticals
  • Cadmium
  • Zinc
  • Tellurium