The role of colour and duplex Doppler ultrasound in the assessment of thyroid nodules.

The role of colour and duplex Doppler ultrasound in investigating nodular thyroid disease was evaluated. Fifty patients with solitary or dominant nodules were studied. All nodules were examined with colour Doppler with spectral analysis performed on vascular lesions. Pathological correlation was available for all nodules. The majority of thyroid nodules could be accurately categorized by their colour Doppler appearances. This was true for both solitary and dominant nodules. All neoplastic nodules (adenomas, carcinomas) contained intra-nodular flow signals. The majority of the colloid nodules were either avascular or had halo flow signals only. A minority of colloid nodules were vascular. These nodules were large (> 2 cm), had dominant halo vessels and cytological evidence of follicular cell hyperplasia. Although colour Doppler lacks absolute specificity in discriminating neoplastic and non-neoplastic thyroid nodules, the data suggests the modality has considerable use in clinical practice. The spectral analysis data was time-consuming to obtain and had less obvious clinical application.