Table 2.

Strengths and Weaknesses of In Vivo Imaging Modalities.

Imaging Modality	Strengths	Weaknesses
Fluorescence	High sensitivity Low cost High-throughput Easy to perform Large number of available probes Able to monitor two or more probes simultaneously	Low resolution Low depth penetration Limited clinical translation
Bioluminescence	High sensitivity Low background signal High-throughput Easy to perform Multispectral imaging	Low resolution Need for genetic modification Limited clinical translation
PET	High sensitivity Unlimited depth penetration Clinical translation	Cost Limited spatial resolution Unable to monitor two or more probes simultaneously
SPECT	Unlimited depth penetration Clinical translation Able to monitor two or more probes simultaneously	Cost Limited spatial resolution Limited sensitivity
MRI	High spatial resolution Clinical translation	Cost Low sensitivity Imaging time