title: Standardization of99mTechnetium pyrophosphate imaging methodology to diagnose TTR cardiac amyloidosis.
abstract: Technetium pyrophosphate (99mTc-PYP) imaging to diagnose transthyretin cardiac amyloidosis (ATTR-CA) has been increasingly utilized. The objective of this study is to provide a standardized99mTc-PYP imaging protocol to diagnose ATTR-CA.
  
  
  
  104 scans from 45 subjects with biopsy-proven ATTR-CA or light-chain cardiac amyloidosis (AL) were assessed. Multiple scans were obtained using different counts (750 vs 2000 K), times to acquisition (1 vs 2 to 4 hours), processing matrix (256 vs 128), and99mTc-PYP dose. Image quality and extracardiac activity was assessed. Quantitative methods using heart-to-contralateral ratios (H/CL) and a visual semiquantitative scale were used to diagnose ATTR-CA.19 The correlation between H/CL ratios and reproducibility of semiquantitative visual scores, acquired using various imaging parameters, were evaluated.
  
  
  
  All imaging parameters had good to excellent image quality. 750 vs 2000 K counts, 1 hour acquisition and 256 matrix, had lower extracardiac activity (P = .00018). 10 mCi of99mTc-PYP v. higher doses showed excellent image quality and less extracardiac activity (P = .0015). Correlation of H/CL ratios was strong (r ≥ 0.92) and reproducibility of semiquantitative visual scores was high (Kappa = 95%).
  
  
  
  An imaging protocol using 750 K counts, 10 mCi of99mTc-PYP, and a 256 matrix was chosen as the standardized imaging protocol since it provided the shortest overall study time (1 vs 2 to 4 hours) and lowest radiation exposure (3 vs 8 to 10 mSv).
authors: Department of Medicine and Division of Cardiology, Columbia University Medical Center, 622 West 168th street, PH10-203E, New York, NY, 10032, USA. sb605@cumc.columbia.edu.
authors: Sabahat
authors: S
authors: Bokhari
authors: Department of Medicine and Division of Cardiology, Columbia University Medical Center, 622 West 168th street, PH10-203E, New York, NY, 10032, USA.
authors: Rachelle
authors: R
authors: Morgenstern
authors: Department of Medicine and Division of Cardiology, Columbia University Medical Center, 622 West 168th street, PH10-203E, New York, NY, 10032, USA.
authors: Richard
authors: R
authors: Weinberg
authors: Department of Medicine and Division of Cardiology, Columbia University Medical Center, 622 West 168th street, PH10-203E, New York, NY, 10032, USA.
authors: Mona
authors: M
authors: Kinkhabwala
authors: Department of Medicine and Division of Cardiology, Columbia University Medical Center, 622 West 168th street, PH10-203E, New York, NY, 10032, USA.
authors: Demetrios
authors: D
authors: Panagiotou
authors: Department of Medicine and Division of Cardiology, Columbia University Medical Center, 622 West 168th street, PH10-203E, New York, NY, 10032, USA.
authors: Adam
authors: A
authors: Castano
authors: Department of Medicine and Division of Cardiology, Columbia University Medical Center, 622 West 168th street, PH10-203E, New York, NY, 10032, USA.
authors: Albert
authors: A
authors: DeLuca
authors: Department of Medicine and Division of Cardiology, Columbia University Medical Center, 622 West 168th street, PH10-203E, New York, NY, 10032, USA.
authors: Andrew
authors: A
authors: Kontak
authors: Department of Biostatistics, Columbia University Medical Center, New York, USA.
authors: Zhezhen
authors: Z
authors: Jin
authors: Department of Medicine and Division of Cardiology, Columbia University Medical Center, 622 West 168th street, PH10-203E, New York, NY, 10032, USA.
authors: Mathew S
authors: MS
authors: Maurer
mesh_terms: D000368:Aged; D000686:Amyloidosis / Q000000981:diagnostic imaging*; D001706:Biopsy; D057791:Cardiac Imaging Techniques / Q000592:standards*; D002309:Cardiology / Q000592:standards; D009202:Cardiomyopathies / Q000000981:diagnostic imaging*; D004164:Diphosphonates; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009154:Mutation; D055414:Myocardial Perfusion Imaging / Q000592:standards; D015609:Organotechnetium Compounds; D011228:Prealbumin / Q000378:metabolism*; D011446:Prospective Studies; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D016698:Technetium Tc 99m Pyrophosphate
chemical_list: D004164:Diphosphonates; D015609:Organotechnetium Compounds; D011228:Prealbumin; C033905:technetium Tc 99m 1,1-diphosphonopropane-2,3-dicarboxylic acid; D016698:Technetium Tc 99m Pyrophosphate
keywords: 99mTc-PYP; ATTR-CA; amyloid; amyloidosis; non-invasive; standardized imaging protocol