Attenuation of the ultrasound beam is a finding associated with which condition?

• A. Pyosalpinx
• B. Endometritis
• C. Ovarian cyst
• D. Fibroid

Answer: (A)

Attenuation of the ultrasound beam happens when the sound energy is greatly reduced as it passes through a structure, often because of gas or very dense material inside that area. In pyosalpinx, the fallopian tube fills with pus and can harbor gas-forming organisms, creating gas pockets within the fluid. Those gas pockets cause notable beam attenuation and can produce shadowing behind the lesion, which helps point to a tubo-ovarian inflammatory process.

Endometritis tends to show thickened or irregular endometrium and pelvic fluid but not the gas-related attenuation pattern. An ovarian cyst usually appears as an anechoic or complex fluid collection with posterior enhancement rather than attenuation. Fibroids are solid and may cast shadowing from dense tissue or calcifications, but the attenuation pattern from gas in pyosalpinx is more characteristic of this finding.