Superb microvascular imaging compared with contrast-enhanced ultrasound to assess microvessels in thyroid nodules.

SMI-BF grade was more affected by vessels of larger inner diameter, while CEUS-EI was more affected by vessels of smaller inner diameter. SMI alone is sufficient for evaluation of blood flow in thyroid nodules, and the diagnostic value of SMI-BF of the periphery is comparable to CEUS hypoenhancement to differentiate thyroid cancer.