Differential Diagnosis of Thyroid Follicular Neoplasm from Nodular Hyperplasia by Shear Wave Elastography

다국어 초록 (Multilingual Abstract)

Objective: More than 50% of diagnostic surgery in cytologically indeterminate thyroid nodules revealed benign nodules of which
nodular hyperplasia (NH) accounted for about half. Preoperative exclusion of NH may decrease diagnostic surgery. We aimed to
study the diagnostic performance of shear wave elastography (SWE) to differentiate follicular neoplasm (FN) from NH in follicular
lesions of thyroid nodules.
Methods: We analyzed the data from 61 patients who underwent SWE before ultrasound-guided core-needle biopsy (CNB) from
August 2016 to May 2018 and CNB results were FN (n=19) and NH (n=42). We analyzed the magnitude of elasticity index (EI) and
patterns of high EI area (EI >36 kPa). The patterns of high EI area was classified as marginal pattern (high EI areas are restricted in
the outer 1/3 of the nodule) and traversing pattern (high EI areas approaching further to the center of the nodule within inner 2/3
of the nodule).
Results: The EMax, EMean, ESD, and percent of high EI area were significantly lower in FN than NH (P<0.001). The diagnostic performance
to predict FN showed sensitivity, specificity, and accuracy of 95%, 90%, and 92% by EMax <42.1 kPa, and of 95%, 79%, and
84% by EMean <23.5 kPa, and of 89%, 93%, and 92% by marginal pattern of high EI area, respectively.
Conclusion: Novel diagnostic criteria of EMax less than 42.1 kPa and marginal pattern of high EI area on SWE can predict FN with high
diagnostic accuracy, waiving diagnostic surgery of NH in indeterminate cytology.