Which diagnostic tool uses sound waves to create images of internal structures?

The correct answer is ultrasound. This diagnostic tool utilizes high-frequency sound waves to produce real-time images of the internal structures of the body. During an ultrasound procedure, a transducer releases sound waves that penetrate the body and bounce back when they encounter different tissues and fluid levels. These returning echoes are then translated into images by a computer, allowing veterinary professionals to visualize organs, blood flow, and even monitor the development of a fetus in pregnant animals.

In contrast, X-rays utilize ionizing radiation to create images of the body's internal structures, primarily focusing on bones and certain soft tissues. MRI (Magnetic Resonance Imaging) employs strong magnetic fields and radio waves to generate detailed images of organs and tissues, making it particularly useful for imaging the brain and soft tissues. CT scans combine X-ray technology with computer processing to create cross-sectional images of the body, providing more detailed views than traditional X-rays but still relying on radiation rather than sound waves.

Thus, the fundamental principle of ultrasound—its use of sound waves rather than radiation—sets it apart from the other diagnostic tools mentioned.