Table 5.
Key features of acquisition protocol of two subtypes of dynamic contrast-enhanced CT
| Dynamic multiphase CT | Dynamic ‘ first pass’/perfusion CT | |
|---|---|---|
| Area of coverage | 6 cm | 7-10 cm depending on tumour |
| Slice thickness | 3 mm | 5 mm |
| kVp | 100 kVp | 80 kVp |
| mAs | According to patient’s weight: <60 Kg, 200 mAs 60-90 Kg, 350 mAs >90kg. 500 mAs | 80 mAs |
| Rate of contrast | 2ml/sec | 5 ml/sec |
| Time delay/phase of acquisition | Pre-contrast, 60 sec, 120 sec, 180 sec and 240 sec. | Scan delay: 5 sec, 22 dynamic acquisitions: first 10 scans every 3 sec, next 5 scans every 2 sec and next 7 scans every 4 sec |
| Reconstruction | Reconstruction interval: 2mm Standard mediastinal window: (windowlevel: 40HU, width: 400HU) | Reconstruction interval: 3 mm Standard mediastinal window: (windowlevel: 40HU, width: 400HU) |
| Parameter available | Peak enhancement (HU), Wash in and wash out percentages | Blood flow, blood volume, permeability, mean transit time, time to peak |