Comparison of Optical Imaging Modalities
Parameter | Fluorescence | Bioluminescence | Optoacoustic | CL |
Principle | Absorption of light excites status of dye and its relaxation emits light | Oxidation of substrate by enzyme emits light | Light is absorbed and causes molecular vibrations that emit sound waves | Charged particles travel quickly through medium and emit light |
Advantage | Easy to perform; large variety of dyes | No incident radiation needed; no background | Safe | Safe and informative |
Disadvantage | Needs excitation source | Is not yet clinical | Needs complex image reconstruction | Needs radioactive preinjection |
Translatable? | Yes | Not currently | Yes | Yes |
Ease to implement | Medium | Medium | Medium | Difficult |
Ease to use | Easy | Medium | Medium | Medium |
Ease to detect | Easy | Easy | Medium | Medium |
Detectable range | Visible spectrum and NIR | 470–750 nm | 400–800 nm (RSOM), 680–980 nm (MSOT) | Ultraviolet-to-visible spectrum |
Preclinical applications | In vitro and in vivo molecular imaging | In vitro and in vivo molecular imaging | In vivo tumor and vasculature imaging | In vivo tumor imaging |
Potential clinical applications | Screening, diagnostic, intraoperative | Stem cell or chimeric antigen receptor T-cell tracking | Muscular dystrophy, vasculature, cancer imaging | Positive lymph nodes and cancer detection |
Cost | Low | Low | Medium | High |