Ultrasonographic and Color Doppler Ultrasonographic Parameters to Discriminate Thyroid Nodules
Abstract
Objective: To determine parameters that can be used to predict malignant thyroid nodules by using grayscale ultrasonography and color Doppler ultrasonography
Materials-methods: Gray-scale ultrasonography and color Doppler ultrasonography findings were retrospectively analyzed in 60 nodules with known histopathology. Of 60 nodules, 12 nodules were malignant. The evaluation criteria for gray-scale ultrasonography were: size, echotexture, internal morphology, contour, presence of microcalcification, and presence of halo sign. The evaluation criteria for color Doppler ultrasonography were: vascular flow pattern and resistive index. Vascular flow patterns were classified as Types I, II, III, and IV.
Results: Irregular contour and type IV flow patterns were the most significant independent predictors of malignancy in malignant thyroid nodules. Resistive index was significantly higher in malignant nodules. The cut off value was established as resistive index ≥0.69; 91% sensitivity and 97% specificity were calculated in
the identification of malignant nodules. A combination of the absence of a halo sign, type IV flow pattern, and irregular contour had the highest specificity and positive predictive value (66.7% sensitivity, 100% specificity, 100% positive predictive value, 92.3% negative predictive value).
Conclusion: We believe that by the integration gray-scale ultrasonography with color Doppler ultrasonography findings, it is possible to determine which nodule is malign/benign without performing fine needle aspiration biopsy (FNAB) and unnecessary operations could be prevented.
Keywords
Thyroid Nodule, Ultrasonography, Doppler Ultrasonography, Resistive Index, Vascularization
References
- 1. Belfiore A, Rosa GL, Giuffrida D, et al. The management of thyroid nodules. J Endocrinol Invest. 1995; 18: 155-158
- 2. Alexander EK, Hurwitz S, Heering JP, et al. Natural history of benign solid and cystic thyroid nodules. Ann Intern Med. 2003; 138: 315-318
- 3. Ivanac G, Brkljacic B, Ivanac K, et al. Vascularisation of benign and malignant thyroid nodules: CD US evaluation. Ultraschall Med. 2007;28:502-506.
- 4. Gharib H. Fine-needle aspiration biopsy of thyroid nodules: advantages, limitations, and effect. Mayo Clin Proc 1994;69:44-49.
- 5. De Nicola H, Szejnfeld J, Logullo AF, et al. Flow pattern and vascular resistive index as predictors of malignancy risk in thyroid follicular neoplasms. J Ultrasound Med. 2005;24:897-904.
- 6. Gharib H, Goellner JR. Fine-needle aspiration biopsy of the thyroid: an appraisal. Ann Intern Med. 1993;118:282- 289.
- 7. Wu HH, Jones JN, Osman J. Fine-needle aspiration cytology of the thyroid: ten years experience in a community teaching hospital. Diagn Cytopathol. 2006;34:93- 96.
- 8. Stacul F, Bertolotto M, De Gobbis F, et al. US, colour-Doppler US and fineneedle aspiration biopsy in the diagnosis of thyroid nodules. Radiol Med. 2007;112:751-762.
- 9. Rago T, Vitti P, Chiovato L, et al. Role of conventional ultrasonography and color flow-doppler sonography in predicting malignancy in 'cold' thyroid nodules. Eur J Endocrinol. 1998;138:41-46.
- 10. Iannuccilli JD, Cronan JJ, Monchik JM. Risk for malignancy of thyroid nodules as assessed by sonographic criteria: the need for biopsy. J Ultrasound Med. 2004;23:1455-1464.