Table 1 Mean value of various count rate variables, relative probe counting efficiency ratio, and T/B ratio for the nine 18F-FDG-avid tissue sites tested by the three different gamma detection probe systems

Averaged target tissue count rate (counts per second)

960 (± 907, range 80–2509)

203 (± 153, range 45–446)

150 (± 121, range 32–322)

0.006

Background tissue count rate in adjacent area of presumed normal tissue (counts per second)

755 (± 858, range 32–2257)

133 (± 104, range 37–344)

71 (± 65, range 18–197)

0.014

Relative probe counting efficiency ratio

6.9 (± 4.4, range 2.2–15.4)

1.5 (± 0.3, range 1.0–2.1)

1.0 (± 0, range 1.0–1.0)

<0.001

Calculated fixed T/B ratio

1.6 (± 0.6, range 1.1–2.5)

1.6 (± 0.5, range 1.2–2.4)

2.3 (± 1.0, range 1.4–4.2)

0.073

Calculated three-sigma criteria count rate (counts per second)

827 (± 901, range 49–2400)

165 (± 117, range 55–400)

94 (± 76, range 31–239)

0.012