Diagnostic imaging refers to a variety of non-invasive methods for identifying and monitoring diseases or injuries via the generation of images representing internal anatomic structures and organs of the patient's body.
Sound waves travel fastest through a solid material. The second fastest medium is a liquid, and the slowest medium is a gas, because sound waves travel by vibrating molecules in a medium. In solids,... Sound waves travel fastest through a solid material.
Requires a medium to travel through. A transverse wave needs no medium to travel through. The reason sound is slower than light is because sound needs a medium to travel through because its longitudinal and transverse waves need no medium so they can reach the space faster.