title: Minimizing patient-specific tracer dose in myocardial perfusion imaging using CZT SPECT.
abstract: Myocardial perfusion imaging (MPI) with SPECT is widely adopted in clinical practice but is associated with a relatively high radiation dose. The aim of this study was to determine the minimum product of tracer dose and scan time that will maintain diagnostic value for cadmium zinc telluride (CZT) SPECT MPI.
  
  
  METHODS
  Twenty-four patients underwent clinically indicated stress MPI using CZT SPECT and a body weight-dependent (3 MBq/kg) (99m)Tc-tetrofosmin tracer dose. Data were acquired for 8 min in list mode. Next, images were reconstructed using 2-, 4-, 6-, and 8-min time frames. Differences between the 8-min reference scan and the shorter scans were determined in segmental uptake values (using the 17-segment cardiac model), ejection fraction, and end-diastolic volume. A 5% difference in segmental uptake was considered to significantly influence the diagnostic value. Next, the quality of the 4-, 6-, and 8-min scans was scored on a 4-point scale by consensus by 3 experienced nuclear medicine physicians. The physicians did not know the scan time or patient information.
  
  
  RESULTS
  Differences in segmental uptake values, ejection fraction, and end-diastolic volume were greater for shorter scans than for the 8-min reference scan. On average, the diagnostic value was influenced in 7.7 segments per patient using the 2-min scans, in comparison to 2.0 and 0.8 segments per patient using the 4- and 6-min scans, respectively. In addition, the 4-min scans led to a significantly reduced image quality compared with the 8-min scans (P < 0.05). This was not the case for the 6-min scan.
  
  
  CONCLUSIONS
  Six minutes was the shortest acquisition time in stress MPI using CZT SPECT that did not affect the diagnostic value for a tracer dose of 3 MBq/kg. Hence, the patient-specific product of tracer dose and scan time can be reduced to a minimum of 18 MBq·min/kg, which may lower the effective radiation dose for patients to values below 1 mSv.
authors.affiliation: Department of Nuclear Medicine, Isala Hospital, Zwolle, The Netherlands MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands jorisvdijk@gmail.com.
authors.forename: Joris D
authors.initials: JD
authors.lastname: van Dijk
authors.affiliation: Department of Nuclear Medicine, Isala Hospital, Zwolle, The Netherlands.
authors.forename: Pieter L
authors.initials: PL
authors.lastname: Jager
authors.affiliation: Department of Cardiology, Isala Hospital, Zwolle, The Netherlands; and.
authors.forename: Jan Paul
authors.initials: JP
authors.lastname: Ottervanger
authors.affiliation: MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
authors.forename: Cornelis H
authors.initials: CH
authors.lastname: Slump
authors.affiliation: Department of Nuclear Medicine, Isala Hospital, Zwolle, The Netherlands.
authors.forename: Jaep
authors.initials: J
authors.lastname: de Boer
authors.affiliation: Department of Nuclear Medicine, Isala Hospital, Zwolle, The Netherlands.
authors.forename: Adrianus H J
authors.initials: AH
authors.lastname: Oostdijk
authors.affiliation: Department of Medical Physics, Isala Hospital, Zwolle, The Netherlands.
authors.forename: Jorn A
authors.initials: JA
authors.lastname: van Dalen
mesh_terms: D000368:Aged; D002104:Cadmium; D005260:Female; D006801:Humans; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000009:adverse effects / Q000379:methods*; D057285:Precision Medicine; D011829:Radiation Dosage; D011849:Radioactive Tracers; D012189:Retrospective Studies; D013691:Tellurium; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000009:adverse effects / Q000379:methods*; D015032:Zinc
chemical_list: C474490:CdZnTe; D011849:Radioactive Tracers; D002104:Cadmium; D015032:Zinc; D013691:Tellurium
keywords: CdZnTe; SPECT; activity; dose; myocardial perfusion imaging