The impact of prompt gamma compensation on myocardial blood flow measurements with rubidium-82 dynamic PET.
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.
Nuclear Medicine, Central Manchester University Hospitals, Oxford Road, Manchester, M13 9WL, United Kingdom. Ian.Armstrong@cmft.nhs.uk.
Ian S
IS
Armstrong
Nuclear Medicine, Central Manchester University Hospitals, Oxford Road, Manchester, M13 9WL, United Kingdom.
Matthew J
MJ
Memmott
Nuclear Medicine, Central Manchester University Hospitals, Oxford Road, Manchester, M13 9WL, United Kingdom.
Christine M
CM
Tonge
Nuclear Medicine, Central Manchester University Hospitals, Oxford Road, Manchester, M13 9WL, United Kingdom.
Parthiban
P
Arumugam
D000368:Aged; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D005080:Exercise Test; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia; D055414:Myocardial Perfusion Imaging; D009206:Myocardium / Q000473:pathology; D009765:Obesity / Q000150:complications / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D012414:Rubidium Radioisotopes
D012414:Rubidium Radioisotopes; C000615479:Rubidium-82
PET; PET/CT imaging; coronary flow reserve; image reconstruction; physics of imaging