Ultrasound Essay

Ultrasound is a commonly used diagnostic imaging modality that involves the use of various frequencies of sound waves. The sound waves are created by means of the Piezoelectric effect, whereby an electrical current is induced through crystals on a transducer, causing them to produce mechanical vibrations which in turn generate ultrasonic sound waves. An image is produced when the waves are propagated through the body and reflected back towards the transducer.

As a non-ionizing imaging tool, ultrasound is used to view a wide range of anatomy, including the thyroid. A sonographer must be able to distinguish between benign and malignant signs in masses and lesions to make accurate reports of their findings, and these signs can differ depending on the structure. The image above displays an abnormal growth in the left thyroid lobe of a patient. There are many features that can be examined to determine whether growths in the thyroid are benign or malignant and so it is critical to examine the features of the mass carefully.

The image of the thyroid nodule above displays both benign and malignant characteristics, although the latter is more prevalent. One of the primary characteristics of thyroid malignancies is the presence of microcalcifications, which appear in 29%-59% of primary thyroid carcinomas (Hoang, Lee, Lee, Johnson, Farrell, 2007). Other characteristics of malignancy are markedly reduced echogenicity and the growth is heterogeneous and complex (Hoang, Lee, Lee, Johnson, Farrell, 2007). The nodule is typically solid, although any present cystic areas are generally small, with the largest being less than half the size of the total volume (Reading, Charboneau, Hay, Sebo, 2005). Interestingly, a positive correlation between the s...

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...d advantage of being able to use higher frequency sound waves, producing images of higher quality. As such, ultrasound to imaging of the thyroid is can also be called high-resolution ultrasonography (Bano & Chaudhary, 2001). With ultrasound, the size and composition of thyroid masses can be determined, as well as the vascularity via the use of Doppler (Bano & Chaudhary, 2001).

While there are certainly benefits in using ultrasound to investigate the thyroid, there are also limitations to its use, as the benignity and malignancy of growths can not be determined with absolute certainty (Parmley, 2012). More importantly, ultrasound cannot detect the activity of the thyroid (Parmley, 2012), which is used in the diagnosis and staging of thyroid cancer. As a result, other methods such as scintigraphy must be used.

With ultrasound being such a prominent imaging modality,