ROLE OF CONVENTIONAL ULTRASONOGRAPHY AND COLOR-FLOW DOPPLER SONOGRAPHY IN PREDICTING MALIGNANCY IN COLD THYROID-NODULES

The aim of the present study was to establish the usefulness of conven tional thyroid ultrasonography (US) and color flow-doppler (CFD) sonog raphy in the assessment of'cold' thyroid nodules. One hundred and four consecutive patients with thyroid nodules who were to undergo surgery were examined by US and CFD before thyroidectomy. Conventional US eva luated the presence of a halo sign, hypoechogenicity and microcalcific ations. The vascular pattern on CFD was classified as follows: Type I, absence of blood now; Type II, perinoduIar blood flow; Type III, mark ed intranodular blood flow. On histology, 30 nodules were diagnosed as malignant (carcinoma, CA) and 74 as benign nodules (BN). On US, the e chographic pattern most predictive for malignancy was absent halo sign , which was found in 20/30 CA and in 17/72 BN (P = 0.0001; specificity 77.0%; sensitivity 66.6%). The most specific combination on US, absen t halo sign/microcalcifications, was found in 8/30 CA and in 5/74 BN ( P < 0.005; specificity 93.2%, sensitivity 26.6%). The Type III pattern on CFD was found in 20/30 CA and 38/74 BN (not statistically signific ant). The combination of absent halo sign on US with Type III pattern on CFD was found in 15/30 CA and in 8/74 BN (P < 0.0001; specificity 8 9.0%, sensitivity 50.0%). The combination of absent halo sigh/microcal cifications on US with Type III pattern on CFD was the most specific c ombination of the two techniques, being found in 5/30 CA and in only 2 /74 BN (P < 0.01; specificity 97.2%, sensitivity 16.6%). In conclusion , findings on US and CFD become highly predictive for malignancy only when multiple signs are simultaneously present in a thyroid nodule. Th us the predictive value of these techniques increases at the expense o f their sensitivity. Only in a small proportion of patients with thyro id carcinoma is US and CFD information highly predictive of malignancy .