Table 2.
Comparison of cell prelabeling versus reporter gene for all major imaging modalities.
| Label | Modality | Cell sensitivity (Small animal) | Cell sensitivity (Large animal) | Advantages | Disadvantages |
|---|---|---|---|---|---|
| Prelabeling | |||||
| Near Infrared dye | IVM, FMT | 1 × 10031 | n/a | high sensitivity(10-17M) high spatial resolution (<1 µm) (IVM) inexpensive multiplex capability improved depth penetration (FMT) | low depth penetration (IVM) limited clinical use invasive procedure (IVM) loss of signal with depth |
| Indium oxine | SPECT | 6 × 10543 | 1 × 107 44 | high sensitivity (10-11M) ease of use multiplex capability | label dilution radioactive dose signal decay planar (not tomographic) low spatial resolution (2–10mm) |
| FDG | PET | 5 × 104 28 | 3 × 107 45 | high sensitivity (10-12M) tomographic natural molecule labeling quantitative | label dilution radioactive dose signal decay cyclotron required expensive low spatial resolution (2–10mm) |
| SPIO NP | MRI | 2 × 10246 | 1.5 × 107 10 | high spatial resolution improved sensitivity no radioactivity | label dilution toxicity low sensitivity (10-12M, MR) highly sequence dependent many imaging artifacts negative contrast method semiquantitative |
| Reporter Genes | |||||
| GFP | IVM | 1 × 10031 | n/a | high sensitivity (10-17M) high spatial resolution (<1 µm) inexpensive multiplex capability serial imaging | low depth penetration limited clinical use invasive procedure loss of signal with depth |
| Firefly Luciferase | BLI | 1 × 103 9 | n/a | high sensitivity (10-17M) inexpensive multiplex capability (Rluc) serial imaging | low spatial resolution loss of signal with depth low light cooled CCD required |
| HSV1TK/SR39TK 18F-FHBG | PET | 1 × 107 47 | 2.5 × 108 10 | high sensitivity (10-12M) tomographic serial imaging clinically approved | radioactive dose signal decay cyclotron required expensive |
Abbreviations: IVM: intravital microsopy; FMT: fluorescence molecular tomography; SPECT Single photon CT; PET: Positron emission tomography; MRI: Magnetic resonance imaging; BLI: Bioluminescence; SPIO: Superparamagnetic Iron Oxide Particles; NP: nanoparticles; HSV1-TK: Herpes Simplex Virus Type I truncated thymidine kinase; SR39TK: Mutant Herpes Simplex Virus Type I truncated mutated thymidine kinase; 18F-FHBG: 18F-radiolabelled 9-[4-fluoro-3-(hydroxyl methyl) butyl] guanine