Prospective evaluation in 123 patients of strain ratio as provided by quantitative elastosonography and multiparametric ultrasound evaluation (ultrasound score) for the characterisation of thyroid nodules

Purpose

This study was done to compare quantitative elastosonography and ultrasound analysis in the characterisation of thyroid nodules.

Materials and methods

From July 2009 to September 2011, 123 patients with 147 thyroid nodules were included in our study. All patients enrolled had to undergo thyroidectomy because of nodular thyroid disease (goitre or nodules). After preliminary examination with conventional ultrasound (US) and colour Doppler US, the patients were examined with elastosonography, using high-level equipment (Toshiba Aplio XG) and quantitative software (Elasto-Q). Each lesion was characterised using an US score (echogenicity, borders, microcalcifications and colour Doppler pattern), and then by elastosonographic strain ratio. Each patient subsequently underwent thyroidectomy. Histological results were used as the gold standard.

Results

Histological examination demonstrated 89 benign and 58 malignant lesions. On average, the strain ratio value was 2.84±2.69 (range, 0.05–14.5; p=0.001). Sensitivity and specificity of the US score were about 56% and 72%, respectively, whereas those of the strain ratio were 93% and 89%, using a cut-off of 2 obtained with receiver operating characteristic (ROC) curve analysis. Elastosonography was more accurate than US and colour Doppler US in characterising thyroid nodules (p=0.002).

Conclusions

Quantitative elastosonography is a useful diagnostic tool in the evaluation of thyroid lesions, and can be used to limit fine-needle aspiration cytology and improve the selection of patients for thyroidectomy.