Ultrasound should never be used over which area?

• A. Calf
• B. Thigh
• C. Forearm
• D. Eyes

Answer: (D)

Ultrasound energy can cause both heating and mechanical effects in tissues, but the eyes are particularly vulnerable. The eye contains delicate structures—the cornea, lens, retina, and optic nerve—that have very limited ability to tolerate energy deposition. Applying therapeutic ultrasound over the eyes could raise temperature or create mechanical damage (such as cavitation), potentially leading to vision changes, cataracts, or retinal injury. For this reason, the orbital region is avoided in standard ultrasound therapy.

Other common treatment areas like the calf, thigh, or forearm can safely receive ultrasound when proper parameters are used, because they have more robust tissues and better heat dissipation.