TABLE 2.

Typical Calibration Procedure and Recommended Additions

Step	Procedure
1	Assay syringe with ¹⁸F. Record activity and time.
2	Inject and mix ¹⁸F in water-filled 20-cm-diameter cylinder.
3	Reassay syringe for residual activity. Record activity and time.
4	Scan phantom, reconstruct image, and measure average value per milliliter from large ROI.
5	Compute new scanner calibration factor (g in Eq. 3) as ratio of ROI average to net concentration in phantom after decay correction.
6*	Compare new scanner calibration factor with average of prior scanner calibration factors.
7*	If there is more than a small difference (e.g., 5%), check all measurement and data entry steps, or repeat steps 1–6.
8	Install calculated scale factor as new scanner calibration for subsequent patient scans.
9*	Scan a known test object (e.g., ⁶⁸Ge/⁶⁸Ga phantom) using standard clinical protocol and measure kBq/mL on reconstructed image.
10*	If there is more than a small difference in measured activity from previous images of test object (e.g., 5%), check all measurement and data entry steps, or repeat steps 1–8.