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, PET, SPECT, ultrasound, electroencephalography, magnetoencephalography, and MRI.
A feature of a radiograph that represent some kind of pathology was first coined "Roentgen signs" after Wilhelm Röntgen, the discoverer of the X-ray.
Early examples of a frequently used QIB are the RECIST criteria, measuring the evolution in tumor size to assess treatment response for patients with cancer, the Nuchal scan used for prenatal screening, or the assessment of lesion load and brain atrophy for patients with multiple sclerosis.
Example QIBs in this vein include the apparent diffusion coefficient,[4] temperature, magnetic susceptibility, standard uptake value (SUV),[5] and shear wave speed.
For a pharmaceutical, device, or procedure to be approved for regular use in the U.S., it must be rigorously tested in clinical trials, and demonstrate sufficient efficacy.
Because surrogate end-points allow researchers to assess a marker rather than the patient, it allows participants to act as their own control, and in many cases allows for easier blinding.
The United States Congress and the Food and Drug Administration have acknowledged the value of imaging biomarkers as evidenced by recent actions that encourage their use.
Although the act does not specifically mention the use of surrogate end-points for medical devices, section 205 requires that the "least burdensome means necessary" be used in their approval.
They also evaluate the qualification study strategy methods and results and ultimately make a decision to accept or reject.
It is a public-private biomedical research partnership aimed to provide grants for the generation of data for clinical biomarker qualification.
The Predictive Safety Testing Consortium, was created by the Critical Path Institute and the Food and Drug Administration to develop a framework needed for data sharing between its members in order to make biomarker qualification easier.
Their initial project was to catalogue the known biomarkers in order to make them readily available to scientists, regulators, and industry representatives (now available on their website).