Impact of regadenoson-induced myocardial creep on dynamic Rubidium-82 PET myocardial blood flow quantification

Abstract

Background Repositioning of the heart during myocardial perfusion imaging (MPI) using Rubidium-82 (Rb-82) PET may occur when using regadenoson. Our aim was to determine the prevalence and the effect of correcting for this myocardial creep on myocardial blood flow (MBF) quantification. Methods We retrospectively included 119 consecutive patients who underwent dynamic rest- and regadenoson-induced stress MPI using Rb-82 PET. The presence of myocardial creep was visually assessed in the dynamic stress PET series by identifying differences between the automatically drawn myocardium contour and the activity. Uncorrected and corrected stress MBFs were compared for the three vascular territories (LAD, LCX, and RCA) and for the whole myocardium. Results Myocardial creep was observed in 52% of the patients during stress. Mean MBF values decreased after correction in the RCA from 4.0 to 2.7 mL/min/g ( P < 0.001), in the whole myocardium from 2.7 to 2.6 mL/min/g ( P = 0.01), and increased in the LAD from 2.5 to 2.6 mL/min/g ( P = 0.03) and remained comparable in the LCX ( P = 0.3). Conclusions Myocardial creep is a frequent phenomenon when performing regadenoson-induced stress Rb-82 PET and has a significant impact on MBF values, especially in the RCA territory. As this may hamper diagnostic accuracy, myocardial creep correction seems necessary for reliable quantification. Electronic supplementary material The online version of this article (10.1007/s12350-019-01649-4) contains supplementary material, which is available to authorized users.

EANM procedural guidelines for PET/CT quantitative myocardial perfusion imaging

“…This is probably one of the biggest technical challenges to quantitative cardiac PET. Particularly difficult to prevent and to correct is the presence of ‘myocardial creep’ due to pharmacologic stress [ 97 ]. Another major issue in quantitative PET is the quality of the injected bolus, which should show a single peak without evidence of detector saturation [ 98 ].…”

Motion correction to enhance absolute myocardial blood flow quantitation by PET

“…17 We have described this occurrence as 'myocardial creep' to refer to the heart drift which is common during pharmacological stress 17 and may occur in * 50% of cases. 18 'Myocardial creep' is most likely due to diaphragmatic/breathing changes occurring as a side effect of pharmacological vasodilation and represents an additional source of motion-based artifact. 17 In addition to patient and/or cardiac motion correction, further enhancement of cardiac PET imaging may be achieved by respiratory motion correction.…”

The next step in improving (semi-)quantitative MPI PET

“…Fifth, patient motion and repositioning of the heart after administration of a stress agent can also negatively affect the reliability of MBF measurements. 9,10 However, this influence can be limited by correcting the dynamic time-frames for possible motion and ''myocardial creep''. 11 Last, the test-retest reliability of MBF quantification is relatively large with a typical uncertainty of 21%.…”