Absolute Quantitation of Myocardial Blood Flow in Human Subjects With or Without Myocardial Ischemia Using Dynamic Flurpiridaz F 18 PET

Abstract

Absolute quantitation of myocardial blood flow (MBF) by positron emission tomography (PET) is an established method of analyzing coronary artery disease (CAD) but subject to the various shortcomings of available radiotracers. Flurpiridaz F 18 is a novel PET radiotracer which exhibits properties of an ideal tracer. Methods A new absolute perfusion quantitation method with Flurpiridaz was developed, taking advantage of the early kinetics and high first-pass extraction by the myocardium of this radiotracer, and the first in human measurements of MBF performed in 7 normal subjects and 8 patients with documented CAD. PET images with time-activity curves were acquired at rest and during adenosine stress. Results In normal subjects, regional MBF between coronary artery territories did not differ significantly, leading to a mean global MBF of 0.73 mL/min/g at rest and 2.53 mL/min/g during stress, with a mean global myocardial flow reserve (MFR) of 3.70. CAD vascular territories with <50% stenosis demonstrated a mean MBF of 0.73 at rest and 2.02 during stress, leading to a mean MFR of 2.97. CAD vascular territories with ≥50% stenosis exhibited a mean MBF of 0.86 at rest and 1.43 during stress, leading to a mean MFR of 1.86. Differences in stress MBF and MFR between normal and CAD territories, as well as between <50% and ≥50% stenosis vascular territories, were significant (P<0.01). Conclusion Absolute quantitation of MBF in humans with the novel PET radiotracer Flurpiridaz is feasible over a wide range of cardiac flow in the presence or absence of stress-inducible myocardial ischemia. The significant decrease in stress MBF and ensuing MFR in CAD territories allows a clear distinction between vascular territories exhibiting stress-inducible myocardial ischemia and those with normal perfusion.

Validation of pixel-wise parametric mapping of myocardial blood flow with 13NH3 PET in patients with hypertrophic cardiomyopathy

“…Of the other available tracers, 82 Rb would probably have major limitations in spatial resolution for transmural measurements because of the relatively long distance covered by its high-energy positrons [33]. Because it is labelled with 18 F, flurpiridaz could possibly be more promising for this purpose, although the definition and validation of convincing models for MBF quantitation are still to be completed [34].…”

Absolute myocardial blood flow vs relative myocardial perfusion: Which one is better?

“…Flourine-18-flurpiridaz is a new PET tracer with longer half-life of 110 minutes which does not require cyclotron on-site; however, data on this radiotracer are preliminary. 14 …”

PET myocardial perfusion quantification: anatomy of a spreading functional technique

“…It has demonstrated a short positron range (1.03 mm) and a high extraction fraction (94%), offering improved image quality as documented by phase I and II trials [7]. Quantification over a wide range of MBF with 18 F-Flurpiridaz has been performed with engaging results that have demonstrated sensitive variations across CAD status [14]. 18 Fluorine-labeled phosphonium derivates ( 18 F-FATPs) have demonstrated potential for PET MPI in preclinical studies.…”