The impact of prompt gamma compensation on myocardial blood flow measurements with rubidium-82 dynamic PET
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Rubidium-82 myocardial perfusion imaging is a well-established technique for assessing myocardial ischemia. With continuing interest on myocardial blood flow (MBF) and myocardial flow reserve (MFR) measurements, there is a requirement to fully appreciate the impact of technical aspects of the process. One such factor for rubidium-82 is prompt gamma compensation (PGC). This study aims to assess the impact of PGC on MBF and MFR calculated from dynamic Rb-82 data.
Dynamic rest and stress images were acquired on a Siemens Biograph mCT and reconstructed with and without PGC in 50 patients (29 male). MBF and MFR were measured in the three main coronary territories as well as globally.
With PGC, statistically significant reductions in MBF were observed in LAD (−6.9%), LCx (−4.8%), and globally (−6.5%) but only in obese patients. Significant increases in MBF were observed in RCA (+6.4%) in only nonobese patients. In very obese patients, differences of up to 40% in MBF were observed between PGC and non-PGC images. In nearly all cases, similar PGC differences were observed at stress and rest so there were no significant differences in MFR; however, in a small number of very obese patients, differences in excess of 20% were observed.
PGC results in statistically significant changes in MBF, with the greatest reductions observed in the LAD and LCx territories of obese patients. In most cases, the impact on stress and rest data is of similar relative magnitudes and changes to MFR are small.
KeywordsPET/CT imaging coronary flow reserve PET image reconstruction physics of imaging
Blood input function
Coronary artery disease
Left anterior descending coronary artery
Left circumflex coronary artery
Myocardial blood flow
Myocardial flow reserve
Positron emission tomography
Prompt gamma compensation
Right coronary artery
There are no conflicts of interest for Ian Armstrong, Matthew Memmott, Christine Tonge, and Parthiban Arumugam associated with this study.
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