Molecular Imaging
Molecular targeting is a powerful diagnostic procedure that may be used to diagnose, monitor, and evaluate cancer, cardiovascular disease, neurological and various other disorders.Many pathological conditions leave unique molecular signatures on the surface of the blood vessels supplying the diseased tissue. By targeting these markers of disease with an imaging contrast agent, information at the molecular level may be acquired. Information about the molecular state of a disease will enable physicians to evaluate and treat numerous diseases more efficiently than current diagnostic methods allow. At the pre-clinical level, molecular imaging can help researchers determine the efficacy of experimental treatments in a longitudinal fashion, streamlining research and significantly reducing the number of experimental animals required for studies. Targeson is currently marketing a novel contrast agent that enables molecular imaging using ultrasound for pre-clinical research, and is developing this technology for clinical use.
The strategy for most molecular imaging techniques is to cause a contrast agent, which may be seen with one or more imaging techniques, to adhere to the diseased tissues. This may be achieved by coating the contrast agent with a molecule that binds one or more molecular signatures of the targeted disease. After injection of the targeted contrast agent, the patient is imaged, and the location and severity of the targeted disease is determined by the detection of the bound contrast agent.
Many imaging modalities, including MRI, nuclear medicine, and some optical imaging techniques, can be utilized for molecular imaging. Targeson’s technology uses ultrasound, which has several advantages over other imaging techniques. The contrast agents Targeson has developed are microscopic gas-filled particles that are encapsulated by a biocompatible lipid shell. The presence of the minute volume of encapsulated gas in the contrast agents induces non-linear transmission of sound, which enables detection of the agents using ultrasound imaging. Microbubble ultrasound contrast agents such as those developed by Targeson enable contrast enhancement that can be orders of magnitude greater than that of tissue or blood. In contrast, techniques such as PET rely upon contrast agents that are radioactive, may not be suitable for frequent diagnostic scans and poses certain limitations for pre-clinical imaging. Ultrasound is inherently real-time, and most imaging procedures can be completed within minutes; procedures such as MRI and PET may require up to several hours to process the acquired imaging data. Although the spatial resolution of ultrasound is generally lower than that of MRI, ultrasound is significantly more sensitive to contrast agents, and recently developed high-frequency ultrasound scanners can enable high-resolution imaging of small animals such as mice. Unlike many other contrast agents. The equipment required for ultrasound imaging is generally less expensive than for other imaging techniques, is highly portable, and is already present in most hospitals.Molecular imaging may also serve as a valuable tool for determining patient response to various therapies. Targeson’s targeted contrast agents have been successfully used to image several pathophysiological processes in mice, rats, and dogs. Ultrasound-based molecular imaging presents an effective and cost-efficient method of determining end points for pre-clinical and clinical trials.