Since the 1970s ultrasound has been used for monitoring what?

• A. Brain imaging
• B. Unborn babies
• C. Heart disease
• D. Bone density

Answer: (B)

Ultrasound became a standard, non-invasive way to image the inside of the body in real time, and in the 1970s its use for pregnancy care expanded dramatically. The main idea is that this technology allows doctors to monitor a fetus without any radiation, simply by sending sound waves and reading the echoes. This makes it ideal for checking unborn babies—watching the heartbeat, measuring growth, tracking movement, assessing amniotic fluid, and checking placenta position or detecting potential problems early. That infant-focused, non-radiation, real-time monitoring is what popularized ultrasound in medical practice during that era.

Other uses mentioned are less typical as the defining application of ultrasound in that period. Brain imaging with ultrasound is limited by the skull, so it isn’t the standard method for brain imaging. Bone density is usually measured with X-ray–based methods like DEXA. Heart monitoring using ultrasound (echocardiography) exists, but the widespread association and major growth of ultrasound in the 1970s came from obstetric monitoring of unborn babies.