Chapters authored
Advanced Ultrasound Techniques in Preoperative Diagnostic of Thyroid Cancers
The most precise evaluation of thyroid masses is by high-sensitive ultrasound. Complementary to B-mode ultrasound, elastography can add valuable information by determining tissue stiffness—an important predictor for malignancy. All major guidelines recommend nodules with high suspicious ultrasound characteristics larger than 1 cm to be addressed to ultrasound-guided fine needle aspiration biopsy (FNAB) to rule out malignancy. The main limitation of this procedure is represented by indeterminate cytology, which accounts for up to 20–25% of biopsy results. Molecular markers imply elevated costs and their performance needs further study. Elastography may be helpful in establishing the optimal therapeutic attitude for this cytological category. Currently, there are two ultrasound elastography methods available for assessing tissue stiffness using the parallel deformation to the applied force direction (strain) or the perpendicular deformation to the force direction (shear wave). These methods will be presented and compared in this chapter, with their indications and limitations for a better understanding of their application in nodular thyroid pathology.
Part of the book: Knowledges on Thyroid Cancer
Role of Elastography in the Evaluation of Parathyroid Disease
Primary hyperparathyroidism is a prevalent disease of the parathyroid glands and the third most common endocrinopathy, especially among postmenopausal women. Secondary hyperparathyroidism is a compensatory response to hypocalcemic states due to chronic renal disease, vitamin D deficiency and malabsorption syndromes, and other chronic illnesses. Elastography can be an effective tool in localizing and identifying parathyroid lesions, whether it is a parathyroid adenoma or hyperplastic parathyroid secondary to chronic kidney disease, by differentiating between possible parathyroid lesions and thyroid nodules, cervical lymph nodes, or other anatomical structures. No current guidelines recommendations are available and no established general cutoff values on the elasticity of parathyroid lesions. We have conducted several prospective studies on primary and secondary hyperparathyroidism, using ultrasound imaging and elastography, shear wave, and strain elastography to better identify the parathyroid lesions and improve the preoperative localization and diagnostic. The results were encouraging, allowing us to determine cutoff values that are different for lesions from primary hyperparathyroidism and secondary hyperparathyroidism and comparing them with normal thyroid tissue and surrounding muscle tissue.
Part of the book: Elastography