What does hypoechoic refer to in ultrasound imaging?

Hypoechoic refers to regions in ultrasound imaging that generate lesser intensity echoes compared to surrounding tissues, resulting in those areas appearing darker on the ultrasound image. This term is commonly used to describe tissues or structures that reflect fewer sound waves back to the transducer, indicating a different composition than surrounding areas—such as fluid-filled spaces, certain tumors, or lesions.

In contrast, areas that generate high intensity echoes would be described as hyperechoic, which appear brighter on the ultrasound. Areas producing no echo would be anechoic and typically indicate fluid, while bright areas typically denote high echogenicity. Understanding these terms is essential for accurately interpreting ultrasound images, as they provide critical information about the composition and potential pathology of the examined tissues.