Table 3.

Quantitative image parameters expressed as mean ± standard deviation and range in parentheses

	Group A	Group B	Group C	Group D	p-value
CNR
Submandibular gland	3.1 ± 2.9	3.0 ± 3.1	4.5 ± 3.6	6.0 ± 5.5	A vs B p = 0.70; B vs C p = 0.12; C vs D p = 0.33; all other p < 0.04
	(1.9–10.1)	(2.7–10.3)	(2.5–11.7)	(3.1–21.4)
Thyroid gland	12.2 ± 6.4	13.6 ± 6.8	14.3 ± 7.7	18.6 ± 8.7	A vs B p = 0.68; B vs C p = 0.96; C vs D p = 0.06; all other p < 0.04
	(3.6–24.4)	(1.5–24.0)	(4.6–42.2)	(4.2–39.3)
Internal jugular vein	13.0 ± 6.9	18.8 ± 8.4	21.8 ± 14.6	27.5 ± 12.9	B vs C p = 0.48; C vs D p = 0.11; all other p < 0.02
	(2.5–30.4)	(6.9–37.0)	(1.9–56.2)	(10.1–56.7)
Common carotid artery	12.9 ± 6.2	15.3 ± 6.7	18.0 ± 12.3	23.2 ± 10.7	A vs B p = 0.15; B vs C p = 0.56; C vs D p = 0.10; all other p < 0.02
	(2.8–27.2)	(5.1–31.1)	(1.0–49.0)	(4.5–50.5)
Figure of merit CNR
Submandibular gland	11.8 ± 19.1	12.5 ± 10.6	29.2 ± 28.2	108.1 ± 70.4	A vs B p = 0.33; C vs D p = 0.22; all other p < 0.03
	(0.1–75.6)	(1.0–56.9)	(0.3–113.9)	(0.2–422.7)
Thyroid gland	109.0 ± 106.7	148.3 ± 112.7	219.9 ± 281.3	424.8 ± 420.6	A vs B p = 0.38; B vs C p = 0.59; all other p < 0.04
	(6.2 ± 357.0)	(1.5–358.6)	(16.7–1415.1)	(13.9 ± 1525.8)
Internal jugular vein	127.3 ± 151.9	282.4 ± 226.8	575.7 ± 716.3	907.0 ± 849.6	B vs C p = 0.13; all other p < 0.04
	(2.9–574.5)	(31.0–770.7)	(2.2–2675.9)	(109.5–2955.9)
Common carotid artery	116.9 ± 108.0	178.3 ± 153.5	398.5 ± 514.9	650.1 ± 649.8	A vs B p = 0.06; B vs C p = 0.22; all other p < 0.04
	(3.5–418.9)	(17.0–619.2)	(0.6–2034.2)	(24.5–2966.9)

CNR, Contrast-to-noise ratio.