Vivian Youngjean Park MD, Presenter: Nothing to Disclose

Eun-Kyung Kim, Abstract Co-Author: Nothing to Disclose

Jin Young Kwak MD, Abstract Co-Author: Nothing to Disclose

Jung Hyun Yoon MD, Abstract Co-Author: Nothing to Disclose

Hee Jung Moon MD, Abstract Co-Author: Nothing to Disclose

We aimed to evaluate the role of the thyroid imaging reporting and data system (TIRADS) and elastography in recommending repeat fine-needle-aspiration (FNA) for solid thyroid nodules with nondiagnostic FNA cytology.

A total of 143 solid thyroid nodules in 141 patients were included. Each was classified according to the TIRADS; solid component, hypoechogenicity or marked hypoechogenicity, microlobulated or irregular margins, microcalcifications, and taller-than-wide shape were considered suspicious US features. Nodules with one, two, three or four, or five suspicious US features were classified as category 4a, 4b, 4c or 5 respectively. Elastography scores were classified according to the Rago and Asteria criteria. We investigated the malignancy risk for each TIRADS category and the corresponding sensitivity, specificity, negative predictive value, positive predictive value and accuracy of elastography.

Of 141 nodules, 25 were malignant, 79 were benign, and 39 were not confirmed. None of the US features, frequencies of TIRADS categories or classification according to the Rago and Asteria criteria significantly differed between benign and malignant nodules. The malignancy risk for TIRADS category 4a, 4b, 4c and 5 were 6.7% (1/15), 15.8% (6/38), 20.7% (17/82) and 12.5% (1/8) respectively, when including nonconfirmed nodules in the denominator. When analyzing confirmed nodules, elastography showed the highest negative predictive value for TIRADS category 4a; sensitivity, specificity, negative predictive value, positive predictive value and accuracy were 0% (0/1), 85.7% (6/7), 85.7% (6/7), 0% (0/1), 75% (6/8) for the Rago criteria and 100% (1/1), 85.7% (6/7), 100 (6/6%), 50% (1/2) and 87.5% (7/8) for the Asteria criteria. The Asteria criteria accurately classified the 1 malignant nodule in the TIRADS category 4a as malignant.

Observation may be considered for solid thyroid nodules with nondiagnostic cytology that are classified as TIRADS category 4a and benign based on Asteria criteria, due to their low malignancy risk and high negative predictive value of elastography. Repeat FNA is warranted for TIRADS category 4b, 4c or 5, regardless of elastography features.

Elastography is a useful tool in recommending repeat FNA for solid thyroid nodules with initial nondiagnostic cytology, when no other suspicious US features are present.

Park, V, Kim, E, Kwak, J, Yoon, J, Moon, H, TIRADS and Ultrasound Elastography: Useful Tools in Recommending Repeat FNA for Solid Thyroid Nodules with Nondiagnostic Fine Needle Aspiration Cytology.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014000.html