Radiomics in PET/CT: More Than Meets the Eye?

Radiomics is defined as the high-throughput extraction of quantitative metrics from medical images (1). One of its main assumptions is that medical images are considered not merely pictures for visual assessment but rather minable quantitative data (2) that may not necessarily be captured by the human eye (3). In this issue of The Journal of Nuclear Medicine, Orlhac et al. present a study comparing visual assessment of uptake heterogeneity on PET images by experts and a subset of radiomics metrics, namely textural features (4). They exploited both clinical and simple simulated PET images, going further than previous studies performed using clinical data only (5-7). Such studies are useful because they provide additional understanding relative to the visual meaning of quantitative metrics that cannot easily be explained to nonspecialists. These studies have focused on the PET component and the F-18-FDG uptake heterogeneity. Similar analyses have been performed with CT (8) and MRI (9).