Ultrasound Risk Categories for Thyroid Nodules and Cytology Results: A Single Institution’s Experience after the Adoption of the 2016 Update of Medical Guidelines by the American Association of Clinical Endocrinologists and Associazione Medici Endocrinologi

Table 1

Dimensions of nodules evaluated by fine needle aspiration, divided by ultrasound risk categories. Data are expressed as the mean ± SD.

	Low risk	Intermediate risk	High risk
	(341)	(489)	(29)
Anteroposterior (mm)				Low risk versus high risk < 0.1
				Low risk versus intermediate risk = NS
	(5–59)	(4–49)	(5–36)
				Intermediate risk versus high risk = NS
Transverse (mm)				Low risk versus high risk = <0.01
				Low risk versus intermediate risk = NS
	(4–40)	(4–42)	(5–35)
				Intermediate risk versus high risk = 0.01
Longitudinal (mm)				Low risk versus high risk < 0.01
				Low risk versus intermediate risk < 0.01
	(7–80)	(6–65)	(5–56)
				Intermediate risk versus high risk < 0.05
Volume (mL)				Low risk versus high risk = NS
				Low risk versus intermediate risk = NS
	(0.1–93.3)	(0.1–64.2)	(0.1–35.7)
				Intermediate risk versus high risk = NS