Imaging biomarker

An imaging biomarker is a biologic feature, or biomarker detectable in an image. In medicine, an imaging biomarker is a feature of an image relevant to a patient's diagnosis. For example, a number of biomarkers are frequently used to determine risk of lung cancer. First, a simple lesion in the lung detected by X-ray, CT, or MRI can lead to the suspicion of a neoplasm. The lesion itself serves as a biomarker, but the minute details of the lesion serve as biomarkers as well, and can collectively be used to assess the risk of neoplasm. Some of the imaging biomarkers used in lung nodule assessment include size, spiculation, calcification, cavitation, location within the lung, rate of growth, and rate of metabolism. Each piece of information from the image represents a probability. Spiculation increases the probability of the lesion being cancer. A slow rate of growth indicates benignity. These variables can be added to the patient's history, physical exam, laboratory tests, and pathology to reach a proposed diagnosis. Imaging biomarkers can be measured using several techniques, such as CT, electroencephalography, magnetoencephalography, and MRI.