Additional value of qualitative strain ultrasound elastography and strain ratio in predicting thyroid malignancy

Abstract

Objective: To detect if strain ultrasound elastography and strain ratio have additional value to the conventional grey scale ultrasound in predicting thyroid malignancy. Patients and methods: This study included 92 thyroid nodules from 62 patients (the mean age was 40.64 ± 13.93). Morphologic aspects of the thyroid nodule in conventional grey scale ultrasonography and elastographic examinations with elastography score and strain ratio (SR) were performed for all nodules. The final diagnosis was confirmed by fine needle aspiration biopsies in 72 nodules and by excisional biopsies in 20 nodules. Results: We found that combination of both conventional ultrasound and strain elastography score have the best diagnostic performance with sensitivity, specificity, PPV, NPV and accuracy accounting for 80%, 97%, 57%, 99% and 96% respectively. The means SR for benign nodules (1.37 ± 0.56) was significantly lower than that for malignant nodules (3.0 ± 0.71) [p-value .003].The optimal SR cutoff is 2.5 with estimated 80% sensitivity, 98% specificity, PPV 67%, NPV 99% and accuracy 97%. Conclusion: The clinical application of elastography score and SR should be carried out hand in hand with conventional sonographic assessment of thyroid nodules to achieve the best diagnostic performance.

Keywords

• Thyroid nodule
• Ultrasound
• Elastography score
• Strain ratio