Molecular imaging

Molecular imaging is a field of medical imaging that focuses on imaging molecules of medical interest within living patients. This is in contrast to conventional methods for obtaining molecular information from preserved tissue samples, such as histology. Molecules of interest may be either ones produced naturally by the body, or synthetic molecules produced in a laboratory and injected into a patient by a doctor. The most common example of molecular imaging used clinically today is to inject a contrast agent (e.g., a microbubble, metal ion, or radioactive isotope) into a patient's bloodstream and to use an imaging modality (e.g., ultrasound, MRI, CT, PET) to track its movement in the body. Molecular imaging originated from the field of radiology from a need to better understand fundamental molecular processes inside organisms in a noninvasive manner.

The ultimate goal of molecular imaging is to be able to noninvasively monitor all of the biochemical processes occurring inside an organism in real time. Current research in molecular imaging involves cellular/molecular biology, chemistry, and medical physics, and is focused on: 1) developing imaging methods to detect previously undetectable types of molecules, 2) expanding the number and types of contrast agents available, and 3) developing functional contrast agents that provide information about the various activities that cells and tissues perform in both health and disease.

Overview

Molecular imaging emerged in the mid twentieth century as a discipline at the intersection of molecular biology and in vivo imaging. It enables the visualisation of the cellular function and the follow-up of the molecular process in living organisms without perturbing them. The multiple and numerous potentialities of this field are applicable to the diagnosis of diseases such as cancer, and neurological and cardiovascular diseases.