Imaging gene expression and signal transduction pathway activity

Molecular imaging is a new field of study that develops the technology to image disease on a cellular or genetic level rather than on a gross anatomical level. The ability to non-invasively monitor different cellular molecular-genetic processes in vivo is the goal of molecular imaging. The pace of progress in this field is encouraging, particularly in the imaging of gene expression. Recent advances in molecular biology have revealed the genetic sequences and genetic mutations that cause diseases including cancer, functional activities of many genes and proteins, as well as the functional properties of various cellular receptors and their ligands. These discoveries improved our understanding of the fundamental mechanisms of various diseases that lead to the burst of novel genetically based therapies. These discoveries are now being extended into radiologic sciences aiming at non-invasive visualization of the molecular-genetic processes involved in various diseases, non-invasive monitoring of responses to therapy on a molecular level, and to assess the effectiveness of gene transfer and expression in novel gene therapy protocols.