Parametric Imaging of Myocardial Viability Using 15O-Labelled Water and PET/CT

This study validated a PET imaging technique for answering a key question in heart failure: which segments of a weakened heart are still viable muscle that could recover, versus dead scar that will not.

The investigators tested whether a “perfusable tissue index” derived from a single oxygen-15 water PET/CT scan could identify viable myocardium, using the established late-gadolinium MRI as the reference. The PET-derived measures correlated well with scar extent on MRI and detected nonviable tissue with good sensitivity and specificity — confirming the PET approach as a valid alternative.

This is a technical validation in a modest sample. It does not test patient outcomes; it establishes that one imaging method agrees with another for assessing viability, which is a prerequisite for using it to guide revascularization decisions.

We rate the evidence moderate. The sample is small and the endpoint is concordance with another test rather than a clinical result, but the work is methodologically sound and contributes to the toolkit for viability assessment.