Main Challenges and Pitfalls in Thyroid Ultrasound

Abstract

Despite recent advances in thyroid imaging, approximately 30–50% of patients with thyroid cancer are misdiagnosed. Convenient ultrasound access, “sufficient” neck size, some constitutional features, and other individual patients’ factors influence the quality of thyroid ultrasound imaging. Various techniques have been developed to improve poor thyroid visualization. High intra- and interobserver variations in thyroid sonography are largely due to the quality of the equipment and the skill level of the operator. High-resolution ultrasound equipment allows several thyroid pathologies to be detected, which used to be considered the norm. Alternatively, there are hyperdiagnostic cases when normal thyroid structures are interpreted as nodules. Rare neck pathologies, such as adenoma and hyperplasia of the parathyroid glands or esophageal diverticulum, may be misdiagnosed due to insufficient experience of the ultrasound operator. Imaging of the thyroid diseases may be accompanied with ultrasound artifacts conferring acoustic shadowing, which is typical for calcifications; reverberation (appears in colloid lesions); marginal artifact of lateral acoustic shadows; posterior echo enhancement (characteristic of fluid collections); and Doppler artifacts. Compression ultrasound elastography can also be accompanied with several artifacts discussed in the chapter.