5. Bimodal contrast agents

5.1 Concept

Today, many effective in vivo imaging techniques are available to aid diagnosis. These include MRI, positron emission tomography (PET), single-photon emission computed tomography (SPECT), computed tomography (CT), confocal and biphotonic microscopy, and ultrasound. Each of these techniques has advantages and disadvantages in terms of spatial and temporal resolution or sensitivity. The concept of multimodal imaging is to combine the advantages of several complementary techniques to overcome their disadvantages, using the same compound as imaging probes for both (or several) techniques. Some devices combining two techniques, such as PET/CT, have appeared in the clinical field.

We have seen that MRI has excellent resolution but low sensitivity, requiring...