Imaging biomarkers 101
I'm supremely confident that you all know exactly what biomarkers are, because you are reading FierceBiomarkers. But in case you've only just joined us, biomarkers can be defined as markers of health, ongoing disease, risk of disease or progression of treatment and can take many forms--for example, increased levels of proteins in the urine, the identification of microRNA in plasma, changes in receptors on the surfaces of cells, falls (or increases) in levels of hormones or the presence of unexpected cells in the bloodstream.
Perhaps less traditionally, imaging biomarkers are coming into play, where researchers and physicians are looking at physical changes in the structures of organs or tissues to track disease and suggest prognosis.
Recent examples of potential imaging biomarkers in development include using the AD signature (an MRI measure of a thinning cerebral cortex) or the blurring of a brain boundary to predict cognitive decline; the presence of characteristic brain atrophy in Huntington's disease; or fMRI suggesting different functional brain activity in children with ADHD. And, most recently, using diffusion tensor imaging to show the possibility of autism as early as at age 6 months, opening up a potential vista of early diagnosis or perhaps even a way to reduce the severity of the condition.
The techniques used to find imaging biomarkers include X-rays, computed tomography (CT), magnetic resonance imaging (MRI) and nuclear medicine techniques such as positron emission tomography (PET). Whereas something like MRI equipment was once rare and incredible costly, the technologies are becoming increasingly commonplace, and could open up a whole new world of biomarker-led imaging. Watch this space. -- Suzanne Elvidge (email)