Manjiri Kiran Dighe MD, Presenter: Nothing to Disclose

Jae H Kim BS, Abstract Co-Author: Nothing to Disclose

C. Diana Jordan MD, Abstract Co-Author: Nothing to Disclose

Bill H. Warren MD, Abstract Co-Author: Nothing to Disclose

Jing Xu MD,PhD, Abstract Co-Author: Nothing to Disclose

Theodore J. Dubinsky MD, Abstract Co-Author: Consultant, ConnexMD, Inc Research grant, Koninklijke Philips Electronics NV

Yongmin Kim PhD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To compare accuracy of ultrasound and elastography of the thyroid using carotid artery pulsation as the compression source in diagnosis and management of thyroid nodules.

A IRB approved study was conducted at the University of Washington comparing the thyroid ultrasound to elastography. 59 patients scheduled for an ultrasound-guided FNA had participated in the study. Ultrasound was performed on IU-22 (Philips, Bothell, WA) machines and Elastography was  performed on Hitachi EUB - 5500 machine prior to the FNA . Strain images were generated off-line and then compared with the FNA results. A quantitative thyroid stiffness index (TSI) was computed as follows: TSI = Strain near carotid artery / Lowest strain in the thyroid nodule. The ultrasound images were retrospectively reviewed by two experienced reviewers who were blinded to the final FNA results. The ultrasound images were scored from 1 to 5 based on preset parameters with increasing suspicion of malignancy. The reviewers were asked to suggest either FNA or follow up based on the imaging characteristics and Society or Radiologists in Ultrasound guidelines.

TSI for papillary carcinoma was higher than other lesions (p=0.02). There was significant discordance between the diagnosis and grade given by the ultrasound features between the reviewers as well as between the suggestions given by the reviewers. Using elastography TSI, only there was a good concordance with the FNA diagnosis. Results are as follows: Concordance in diagnosis for reviewer 1 - 64%, Concordance in diagnosis for reviewer 2 - 55%, Discordance in diagnosis between reviewers - 33.33%, Discordance in suggestion (FU or FNA) - 35.2%, TSI concordance with diagnosis using a cut-off of 18 - 77.7%, Decrease in the number of FNAs on using a combined approach - 37%, Accuracy on using a combined approach compared to only ultrasound appearance to suggest FNA - 79.6%.

Our study results indicate elastography by pulsation of the carotid artery can serve as a repeatable and operator-independent compression source for thyroid elastography. A combined approach of using the ultrasound features and elastography decreased the number of FNA procedures and increased the accuracy.

A combined approach of using ultrasound features and elastography could potentially decrease the number of thyroid FNAs as well as increase the accuracy in diagnosis.

Dighe, M, Kim, J, Jordan, C, Warren, B, Xu, J, Dubinsky, T, Kim, Y, et al, , Thyroid US and Elastography Using Carotid Artery Pulsation: Utility of a Combined Approach in Diagnosis and Management.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6010006.html