Molecular imaging and gene therapy

Molecular imaging is an emerging field of study that deals with imaging of disease on a cellular or genetic level rather than on a gross level. Recent advances in this field show promise, particularly in the imaging of gene e xpression. This article reviews the use of nuclear medicine, magnetic reson ance, and optic imaging to visualize gene expression. A review is presented of current in vitro assays for protein and gene expression and the transla tion of these methods into the radiologic sciences. The merging fields of m olecular biology, molecular medicine, and imaging modalities may provide th e means to screen active drugs in vivo, image molecular processes, and diag nose disease at a presymptomatic stage.