Table 1 Imaging modalities for in vivo tracking of immune cells
From: Immune cell labelling and tracking: implications for adoptive cell transfer therapies
Heading | Modality | Advantages | Disadvantages |
|---|---|---|---|
Nuclear medicine imaging | PET | High sensitivity and specificity; no depth limit; clinically applicable; quantitative | Ionizing radiation exposure; expensive; relatively low spatial resolution 5 mm; no standardized cell labeling method |
SPECT | High sensitivity and specificity; no depth limit; clinically applicable; cell tracking at late time points | Ionizing radiation exposure; expensive; long scan times; relatively low spatial resolution 10 mm; no standardized specific cell labeling method | |
Magnetic Resonance imaging | MRI | High resolution (more than 0.1 mm); no ionizing radiation exposure; clinically applicable; possible quantification (indirect) | Lower sensitivity than PET/SPECT; high costs; contrast agents interference with cells; long scan times |
Optical imaging | MI | Visualization of cell processes and interactions; time-lapse imaging | Photobleaching, phototoxicity; diffraction limit of light; no translational potential for in-vivo imaging |
BLI | Short acquisition time; high sensitivity (100 cells); high signal-to-noise ratio (no background signal) | No translational potential for in-vivo imaging; diffraction and absorption of light by tissues; immunogenicity or gene silencing; erroneous readouts; signal quantification; half-life and stability of enzymes; limited penetration depth (3 cm) | |
FLI | Low cost; radiation free; easy labeling method; real-time | Tissue autofluorescence and absorption; limited penetration depth (1 cm); poor spatial resolution (photon scattering); limited quantification |