Table 1.
Summary of technical details and comparison of PET/CT, DCE-CT and DW-MRI.
| Modality | FDG-PET/CT | DCE-CT | DW-MRI |
|---|---|---|---|
| Principle | Describing tumour metabolism using the radioactive tracer FDG | Visualizes and measures tumour blood flow and blood volume. | Shows diffusion of water molecules within the tissue conditioned by cellular density |
| Patient preparation | 4- to 6-h fast 1-h rest after injection |
30-min rest after injection | No preparation |
| Examination time | 20 min | 2 min | 15 min (per bed position) |
| Postprocessing | 10 min | 10-15 min | 10 min |
| Quantification | Possible (SUV), but not necessary | Possible, but unreliable | Possible (ADC), but not very useful |
| Radiation dose | 5–15 mSv, dependant on CT protocol and FDG dose | 10–20 mSv, dependant on protocol | No radiation |
| Strength | High throughput Well validated Very sensitive |
Functional modality High accuracy |
No radiation No preparation No contrast Sensitive |
| Limitations | FDG not specific for cancer Radiation dose |
Respiratory motion Reproducibility Radiation dose |
Low SNR Respiratory motion and cardiac pulsation cause artefacts |
DCE-CT, dynamic contrast-enhanced CT; DW-MRI, diffusion-weighted magnetic resonance imaging; FDG-PET/CT, integrated positron emission tomography and CT with 18F-FDG; ADC, apparent diffusion coefficient; SUV, standardized uptake value.