ARDMS (American Registry for Diagnostic Medical Sonography) Practice Test

Which ultrasound feature indicates the presence of a cyst?

1. A solid mass with irregular borders

2. A well-defined, anechoic area with a thin wall

3. A heterogeneous mass with shadowing

4. A hypervascular lesion

The correct answer is: A well-defined, anechoic area with a thin wall

A cyst is typically characterized by specific ultrasound features, and the presence of a well-defined, anechoic area with a thin wall is a classic indicator of its existence. In ultrasound imaging, an anechoic appearance means that the structure does not reflect sound waves, allowing it to appear dark on the ultrasound screen. This feature is indicative of fluid-filled structures, which is consistent with the characteristics of a cyst. Additionally, the thin wall surrounding this anechoic area suggests that it is not a solid mass, reaffirming that it is a benign and likely simple cyst. This contrasts with other options which describe structures that are solid or have varying echogenicity, indicating different pathologies such as tumors or complex masses. Therefore, identifying a well-defined, anechoic area with a thin wall is crucial for recognizing a cyst in ultrasound examinations.