Simplify the following text for a Grade 11 native English-speaking person.
Original: Diagnostic sonography ( ultrasonography ) is an ultrasound-based diagnostic imaging technique used for visualizing subcutaneous body structures including tendons , muscles , joints , vessels and internal organs for possible pathology or lesions .
Simplified: Diagnostic ultrasonography is the use of ultrasound to visualize hidden body structures . This medical imaging technique is used to display muscles , tendons , and other internal organs .