Positron emission tomography for assessment of viability.
OBJECTIVE
The recent success of magnetic resonance imaging for viability assessment has raised questions about the future role of positron emission tomography and older imaging modalities in the assessment of viability. Recent information, however, indicates that positron emission tomography will remain a valuable tool.


RESULTS
The primary positron emission tomography tracer used for assessment of viability is 18F-fluorodeoxyglucose, a glucose analogue that exhibits enhanced uptake in ischemic tissue. The finding of enhanced 18F-fluorodeoxyglucose uptake and a relative reduction in perfusion is considered the positron emission tomography correlate of myocardial hibernation. The mismatch pattern has been shown to identify patients with improvement in systolic function, heart failure symptoms, and prognosis with revascularization. Mismatch identifies a subset of patients with vulnerable myocardium who have a higher likelihood of a cardiac event compared with those without significant mismatch. Delay in revascularization may pose extra risk for those with mismatch. Positron emission tomography and magnetic resonance imaging demonstrate a close correlation in the detection of viable myocardium. The development of combined positron emission tomography/computed tomography scanners can reduce imaging time and improve functional-anatomic correlations.


CONCLUSIONS
Positron emission tomography imaging utilizing 18F-fluorodeoxyglucose and perfusion tracers provides valuable diagnostic and prognostic information in patients with ischemic left ventricular dysfunction and has comparable accuracy to competing technologies for detection of viability.
Sawada
Stephen G
SG
Indiana University, Krannert Institute of Cardiology, Indianapolis 46202, USA. ssawada@iupui.edu
D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000503:physiopathology; D019788:Fluorodeoxyglucose F18; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D014022:Tissue Survival / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology
D019788:Fluorodeoxyglucose F18