Table 1.

A brief comparison of the various techniques for in vivo molecular imaging.

Modality	Resolution	Sensitivity	Tissue Penetration	Quantitation capability	Cost	Clinical potential
Fluorescence	medium	medium	poor	poor	$	low
Ultrasound	medium	low	medium	poor	$	high
MRI	high	low	good	poor	$$$	high
SPECT	medium	high	good	good	$$	high
PET	low	high	good	good	$$$	high