Table 2.
Techniques used on each make and model of scanner to obtain 20 repeated free-in-air CTDI measurements using a 10 cm pencil ionization chamber suspended at isocenter. All scans were performed in axial mode; nominal beam width can be calculated by multiplying the number of channels by the channel width.
| Scanner make and model | kVp | mA | Exposure time (s) | No. of channels | Channel width (mm) | Bowtie |
|---|---|---|---|---|---|---|
| GE VCT | 120 | 350 | 1 | 64 | 0.625 | Large |
| GE LightSpeed 16 | 120 | 250 | 1 | 16 | 1.25 | Large |
| Siemens Sensation 64 | 120 | 350 | 1 | 24 | 1.2 | Large |