ARDMS (American Registry for Diagnostic Medical Sonography) Practice Test

What imaging characteristic indicates a potential cystic structure on ultrasound?

1. An echogenic appearance

2. A fluid-filled sac that does not transmit sound

3. Nodular growths

4. Absence of blood supply

The correct answer is: A fluid-filled sac that does not transmit sound

The typical imaging characteristic that indicates a potential cystic structure on ultrasound is the presence of a fluid-filled sac that does not transmit sound. Cysts are usually anechoic, meaning they appear dark on ultrasound due to their fluid content. This lack of internal echoes gives them a distinctive appearance, allowing practitioners to differentiate them from solid masses. Additionally, cystic structures often show a well-defined border, with the surrounding tissue appearing brighter, which further indicates their fluid-filled nature. In contrast, an echogenic appearance typically suggests solid tissue rather than fluid, which would not indicate a cystic structure. Nodular growths usually imply a solid mass, not a cyst, and the absence of blood supply generally relates to the vascularity of a lesion, which is more indicative of a solid tumor rather than a cyst. Thus, the characteristics of the fluid-filled sac that does not transmit sound are definitive in confirming the presence of a cyst.