Diagnostic Performance Evaluation of Practice Guidelines, Elastography and Their Combined Results for Thyroid Nodules: A Multicenter Study.

The purpose of this multicenter study was to compare the differential diagnostic value of the 2015 American Thyroid Association (ATA) and 2017 American College of Radiology (ACR) practice guidelines and elastography in thyroid nodules. This study also investigated whether the diagnostic value of practice guidelines can be improved, and the unnecessary biopsy rate decreased in combination with elastography. A total of 498 thyroid nodules were evaluated using the ATA and the ACR guidelines. Strain elastography, acoustic radiation force impulse imaging and point-shear wave elastography were used to assess the nodules. The suspicious levels were downgraded or upgraded after combination and unnecessary biopsy rates were calculated, respectively. The diagnostic performance of the practice guidelines was better than that of elastography. The ACR guidelines had a lower unnecessary biopsy rate and similar diagnostic performance compared with the ATA guidelines. The unnecessary biopsy rates significantly decreased when the ACR guidelines were combined with elastography, but the rates did not decrease when the ATA guidelines were combined with elastography.