Shear Wave Elastography May Add a New Dimension to Ultrasound Evaluation of Thyroid Nodules: Case Series with Comparative Evaluation
Figure 6
A benign thyroid nodule in a patient with solitary nodule in the thyroid isthmus that was suspicious on power Doppler ultrasound (not shown). The SSWE was true negative and the strain elastography was false positive for thyroid cancer. (a): The thyroid nodule in coronal plane on supersonic shear wave elastography (SSWE) (upper image) and B-mode ultrasound (lower image). The nodule is very soft on SSWE in contradiction to strain elastography (b). In the centre of the circular ROIs punctuate increased stiffness of small calcifications that are also visible on B-mode (lower image) is seen. Also artifacts of increased stiffness in the isthmus of the thyroid are visible. These artifacts are due to trachea (star arrow) and can be avoided with imaging in paracoronal plane of the nodule that does not incorporate the trachea. (b): The thyroid nodule (ROI 1-yellow) on strain elastography in sagittal plane, where the comparison with upper part of normal tissue of isthmus (ROI 2-pink) is possible. The strain color map (left) presents mostly stiff nodule-thyroid nodule score 3. The time-strain graph (right) presents that the lesion is more than 2 times stiffer than thyroid tissue.
