Imaging biomarkers allow earlier detection of disease compared to molecular biomarkers, and streamline translational research in the drug discovery marketplace. For example, one could determine the percent of receptors a drug targets, shortening the time and money of research during the new drug development stage.  Imaging biomarkers also are non-invasive, which is a clinical advantage over molecular biomarkers. Some of the image-based biomarkers are X-Ray, Computed Tomography (CT), Positron Emission Tomography (PET), Single Photo Emission Computed Tomography (SPECT) and Magnetic Resonance Imaging (MRI).
Many new biomarkers are being developed that involve imaging technology.  Imaging biomarkers have many advantages.  They are usually noninvasive, and they produce intuitive, multidimensional results.  Yielding both qualitative and quantitative data, they are usually relatively comfortable for patients.  When combined with other sources of information, they can be very useful to clinicians seeking to make a diagnosis.
Cardiac imaging is an active area of biomarker research.  Coronary angiography, an invasive procedure requiring catheterization, has long been the gold standard for diagnosing arterial stenosis, but scientists and doctors hope to develop noninvasive techniques.  Many believe that cardiac computed tomography (CT) has great potential in this area, but researchers are still attempting to overcome problems related to "calcium blooming," a phenomenon in which calcium deposits interfere with image resolution.   Other intravascular imaging techniques involving magnetic resonance imaging (MRI), optical coherence tomography (OCT), and near infrared spectroscopy are also being investigated.
Another new imaging biomarker involves radiolabeled fludeoxyglucose.  Positron emission tomography (PET) can be used to measure where in the body cells take up glucose.  By tracking glucose, doctors can find sites of inflammation because macrophages there take up glucose at high levels.  Tumors also take up a lot of glucose, so the imaging strategy can be used to monitor them as well.   Tracking radiolabeled glucose is a promising technique because it directly measures a step known to be crucial to inflammation and tumor growth.