When disease occurs, the biochemical activity of cells begins to change. This abnormal cellular activity begins to affect body tissue and structures, causing anatomical change that may be seen on CT or MRI scans.
Molecular imaging can detect these cellular changes that occur early in the course of the disease—often well before the structural changes that can be seen on CT or MR images.
Most molecular imaging procedures involve an imaging device and an imaging agent, also known as a probe. Once the imaging agent is introduced into the body, it accumulates in a target organ or attaches to specific cells. The imaging device detects the imaging agent and creates pictures that show how it is distributed in the body. This distribution pattern helps physicians see how well organs and tissues are functioning.