[Diagnostic value of combination of US and MRI in preoperative prediction for the extrathyroidal extension of papillary thyroid carcinoma].

Objective: The purpose of the present study was to evaluate the diagnostic performance of preoperative ultrasonography(US), magnetic resonance imaging(MRI) and US combined with MRI in the prediction of extrathyroidal extension(ETE) in patients with papillary thyroid carcinoma(PTC). Methods: Between January 2013 and December 2016, a total of 83 consecutive patients underwent surgery for pathologically confirmed PTCs with ETE. We analyzed all patients with PTC with ETE who received preoperative combination of US and MRI scan to evaluate ETE. Results: For minimal ETE, the accuracy was 92.2%(47/51) of US, 74.5%(38/51) of MRI, and their combination was 98.0%(50/51). The differences of the three methods for minimal ETE were statistically significantly different( P =0.000). For extensive ETE, the accuracy was 62.5%(20/32) of US, 87.5%(28/32) of MRI, and their combination was 93.8%(30/32). The different of the three methods for extensive ETE was statistically significantly different( P =0.000). For the total accuracy of ETE, US was 80.7%(67/83), MRI was 79.5% (66/83), and their combination was 96.4%(80/83). The difference of the three methods for ETE was statistically significantly different( P =0.001). Conclusion: The combination of US and MRI can improve the preoperative diagnostic accuracy of ETE for PTC.