Assessment of intra- and interobserver reproducibility of rest and cold pressor test-stimulated myocardial blood flow with 13N-ammonia and PET

Thomas H. Schindler, Xiao Li Zhang, John O. Prior, Jerson Cadenas, Magnus Dahlbom, James Sayre, Heinrich R. Schelbert

Research output: Contribution to journalArticlepeer-review

Abstract

Purpose: We investigated the intraobserver reproducibility of myocardial blood flow (MBF) measurements with PET at rest and during cold pressor test (CPT), and the interobserver agreement. Methods: Twenty normal volunteers were studied. Using 13N-ammonia, MBF was measured at rest and during CPT and measurement was repeated in a 1-day session (short-term reproducibility; SR). After a follow-up of 2 weeks, MBF was measured again at rest and during CPT and compared with the initial baseline measurement (long-term reproducibility; LR). In addition, adenosine-induced hyperemic MBF increases were assessed. Results: Assessment of the SR did not show a significant absolute difference in MBF at rest, MBF during CPT or the endothelium-related change in MBF from rest to CPT (ΔMBF) (0.09 ± 0.10, 0.11 ± 0.09, and 0.08 ± 0.05 ml/g/min; p = NS), and they were linearly correlated (r = 0.72, r = 0.76 and r = 0.84; p < 0.0001). Corresponding values for standard error of the estimate (SEE), as indicative for the range of MBF measurement error, were 0.14, 0.14, and 0.09 ml/g/min. The LR yielded relatively higher but non-significant absolute differences in the MBF at rest, MBF during CPT and ΔMBF (0.10 ± 0.10, 0.14 ± 0.10, and 0.19 ± 0.10 ml/g/min; p = NS), and paired MBFs significantly correlated (r = 0.75, r = 0.71, and r = 0.60; p < 0.001). Corresponding SEEs were 0.13, 0.15, and 0.16 ml/g/min. The interobserver analysis yielded a high correlation for MBF at rest, MBF during CPT, and hyperemic MBF (r = 0.96, SEE=0.04; r = 0.78, SEE=0.11; and r = 0.87, SEE=0.28; p < 0.0001, respectively), and also a good interobserver correlation for ΔMBF (r = 0.62, SEE=0.09; p < 0.003). Conclusion: Short- and long-term MBF responses to CPT, as an index for endothelium-related coronary vasomotion, can be measured reproducibly with 13N-ammonia PET. In addition, the high interobserver reproducibility for repeat analysis of MBF values suggests the measurements to be largely operator independent.

Original languageEnglish (US)
Pages (from-to)1178-1188
Number of pages11
JournalEuropean Journal of Nuclear Medicine and Molecular Imaging
Volume34
Issue number8
DOIs
StatePublished - Aug 2007

Keywords

  • Blood flow
  • Circulation
  • Endothelium
  • Reproducibility
  • Risk factors

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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