Comparison of color-Doppler and qualitative and quantitative strain-elastography for differentiation of thyroid nodules in daily practice
OBJECTIVE: Strain-elastography provides a new ultrasound-based method that can offer information about the stiffness of thyroid nodules as an indicator of malignancy. The aim of our study was to compare the utility of color-Doppler and strain-elastography in differentiating between benign and malignant nodules. DESIGN AND METHODS: 77 thyroid nodules (70 benign and 7 malignant) from 70 unselected patients (48 female/22 male, mean age 49.7±14.3 years) were evaluated with color-Doppler and elastography based on a five-scale elastogram score for qualitative elastography and strain ratio for quantitative elastography. As reference tissue we chose normal thyroid tissue [strain ratio a (SR a)] and cervical muscles [strain ratio b (SR b)]. The cytological or histological results were used as a reference standard. Diagnostic performances of qualitative and quantitative elastography were compared using ROC curves. RESULTS: Vascularization score 3 or 4 was associated with malignancy (p=0.024) as well as elastogram score 4 or 5 (p=0.070, n.s.s.). SR a was indicatively higher and SR b lower in the group of malignant nodules (p=0.065 and p=0.246, n.s.s.). The best cut-off points predicting malignancy were 3.32 for SR a (66.7% sensitivity, 83.3% specificity) and 0.10 for SR b (71.4% sensitivity, 67.1% specificity). CONCLUSION: In our study, the accuracy of elastography did not surpass other sonographic parameters in differentiating thyroid nodules. The technique can play a role as a supplementary parameter in assessment of malignancy to improve diagnostic efficacy. The best parameter is SR a, but SR b can serve as an alternative if SR a is not assessable.
Key wordsElasticity score Strain ratio Thyroid cancer Ultrasound
- 3.Gharib H, Papini E, Paschke R, et al, 2010 American Association of Clinical Endocrinologists, Associazione Medici Endocrinologi, and European Thyroid Association Medical Guidelines for Clinical Practice for the Diagnosis and Management of Thyroid Nodules. Endocr Pract 16: 1–43.CrossRefGoogle Scholar
- 7.Fukunari N, 2007 More accurate and sensitive diagnosis for thyroid tumors with elastography. Medix 20: Suppl 3: 16–19.Google Scholar
- 8.Pacini F, Schlumberger M, Dralle H, Elisei R, Smit JWA, Wiersinga W and the European Thyroid Cancer Taskforce, 2006 European consensus for the management of patients with differentiated thyroid carcinoma of the follicular epithelium. European Journal of Endocrinology 154: 787–803.CrossRefGoogle Scholar
- 9.American Thyroid Association (ATA) Guidelines Task-force on Thyroid Nodules and Differentiated Thyroid Cancer, Cooper DS, Doherty GM, Haugen BR, et al, 2009 Revised American Thyroid Association Management Guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid 19: 1167–1214.CrossRefGoogle Scholar