|
|
|
|
|
The procedure for calibration is as follows:
1. Measure the background activity of the twilite.
2. Fill a phantom with radioactivity, typically 200-500 kBq/cc. Shake the phantom well to homogenize the radioactivity concentration.
3. Use the same catheter as in the experiment.
4. Fill the catheter with fluid from the phantom.
5. Insert the catheter with the radioactivity into the measuring head, using the appropriate template.
6. Position the phantom in the PET scanner.
7. Start data acquisition of PET and twilite simultaneously. The same clock time have to be set for both the PET scanner and the sampler computer.
8. Reconstruct the PET image, including attenuation correction, outline a volume of interest (VOI) in the middle of the phantom and determine the average value of the radioactivity in this volume of interest. This value represents the activity to which the Sampler is going to be calibrated. The step can be easily achieved using the basic PMOD tool PVIEW.
Note: The average value within the VOI has to be in [kBq/cc].
9. Use the PMOD calibration tool to calculate the calibration factor.