title: Measurement of absolute myocardial blood flow in humans using dynamic cardiac SPECT and99mTc-tetrofosmin: Method and validation.
abstract: The objective of this study was to measure myocardial blood flow (MBF) in humans using99mTc-tetrofosmin and dynamic single-photon emission computed tomography (SPECT).
  
  
  
  Dynamic SPECT using99mTc-tetrofosmin and dynamic positron emission tomography (PET) was performed on a group of 16 patients. The SPECT data were reconstructed using a 4D-spatiotemporal iterative reconstruction method. The data corresponding to 9 patients were used to determine the flow-extraction curve for99mTc-tefrofosmin while data from the remaining 7 patients were used for method validation. The nonlinear tracer correction parameters A and B for99mTc-tefrofosmin were estimated for the 9 patients by fitting the flow-extraction curve [Formula: see text] for K1values estimated with99mTc-tefrofosmin using SPECT and MBF values estimated with13N-NH3using PET. These parameters were then used to calculate MBF and coronary flow reserve (CFR) in three coronary territories (LAD, RCA, and LCX) using SPECT for an independent cohort of 7 patients. The results were then compared with that estimated with13N-NH3PET. The flow-dependent permeability surface-area product (PS) for99mTc-tefrofosmin was also estimated.
  
  
  
  The estimated flow-extraction parameters for99mTc-tefrofosmin were found to be A = 0.91 ± 0.11, B = 0.34 ± 0.20 (R2= 0.49). The range of MBF in LAD, RCA, and LCX was 0.44-3.81 mL/min/g. The MBF between PET and SPECT in the group of independent cohort of 7 patients showed statistically significant correlation, r = 0.71 (P < .001). However, the corresponding CFR correlation was moderate r = 0.39 yet statistically significant (P = .037). The PS for99mTc-tefrofosmin was (0.019 ± 0.10)*MBF + (0.32 ± 0.16).
  
  
  
  Dynamic cardiac SPECT using99mTc-tetrofosmin and a clinical two-headed SPECT/CT scanner can be a useful tool for estimation of MBF.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 185 Berry St., Suite 350, San Francisco, CA, 94143-0946, USA. uttam.shrestha@ucsf.edu.|Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. uttam.shrestha@ucsf.edu.
authors.forename: Uttam
authors.initials: U
authors.lastname: Shrestha
authors.affiliation: Division of Cardiology, Department of Medicine, University of California, San Francisco, CA, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Sciammarella
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 185 Berry St., Suite 350, San Francisco, CA, 94143-0946, USA.
authors.forename: Fares
authors.initials: F
authors.lastname: Alhassen
authors.affiliation: Division of Cardiology, Department of Medicine, University of California, San Francisco, CA, USA.
authors.forename: Yerem
authors.initials: Y
authors.lastname: Yeghiazarians
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 185 Berry St., Suite 350, San Francisco, CA, 94143-0946, USA.
authors.forename: Justin
authors.initials: J
authors.lastname: Ellin
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 185 Berry St., Suite 350, San Francisco, CA, 94143-0946, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Verdin
authors.affiliation: Division of Cardiology, Department of Medicine, University of California, San Francisco, CA, USA.|School of Medicine and Public Health, University of Newcastle, Newcastle, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Boyle
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 185 Berry St., Suite 350, San Francisco, CA, 94143-0946, USA.|Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
authors.forename: Youngho
authors.initials: Y
authors.lastname: Seo
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 185 Berry St., Suite 350, San Francisco, CA, 94143-0946, USA.|Division of Cardiology, Department of Medicine, University of California, San Francisco, CA, USA.
authors.forename: Elias H
authors.initials: EH
authors.lastname: Botvinick
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, 185 Berry St., Suite 350, San Francisco, CA, 94143-0946, USA.|Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
authors.forename: Grant T
authors.initials: GT
authors.lastname: Gullberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001783:Blood Flow Velocity; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin
keywords: Dynamic SPECT; ammonia PET; myocardial blood flow quantification; tracer kinetics