Francesca Zanderigo, PhD and Colleagues Investigate and Advance the Possibility of Quantifying PET Images using Non-Invasive Approaches

Francesca Zanderigo, PhD

In an article published in the Journal of Cerebral Blood Flow & Metabolism, Francesca Zanderigo, PhD and colleagues R. Todd Ogden, PhD and Ramin Parsey, MD, PhD compared the capability of 5 reference region approaches to reliably quantify Positron Emission Tomography (PET) data for each of 5 radioligands commonly used to study neuropsychiatric disorders. One of the approaches, the Likelihood Estimation in Graphical Analysis with Reference Region, was proposed for the first time in the article. Using data from 633 PET scans, the researchers analyzed each of the approaches in terms of their accuracy, precision, number of outliers, and correlation with other invasive forms of analysis. They found that reference region approaches can be used satisfactorily with some radioligands, but not with others.

PET uses radioactively labeled molecules, called radioligands, to create images of biological processes. In recent years PET has become an important tool for studying the biological processes that underlie psychiatric disorders. A method known as analysis with full arterial input function is widely considered the “gold standard” for PET research, but it is invasive and costly, requiring the repeated collection of blood from the patient’s or research subject’s radial artery. Non-invasive approaches to PET quantification, including those that rely on reference region rather than blood analysis, are being developed to make PET easier, less costly, and therefore more accessible for both research and clinical practice.

In their study, Dr. Zanderigo and her colleagues compared the results of reference region approaches to the results of full arterial input function analysis for 5 widely adopted radioligands, including those used to study serotonin receptors, serotonin transporters, beta-amyloid plaques, and metabotropic glutamate receptors. The article, titled “Reference region approaches in PET: a comparative study on multiple radioligands” was published January 31, 2013.