What is the mechanism of an acoustic shadow seen on USG?: (A) Refraction, (B) Reflection, (C) Aifacts, (D) Obstruction
Answer is B. An acoustic shadow is an echo free area located behind an insonated structure. It is caused by total reflection of the ultra sound waves causing a shadow behind it. Reference: The Practice of Ultrasound: A Step-by-Step Guide to Abdominal Scanning By Behold Block page 49.