What is the disadvantage of ultrasound?

Disadvantages of ultrasound compared with other techniques

1. The major disadvantage is that the resolution of images is often limited.
This is being overcome as time passes, but there are still many situations where X-rays produce a much higher resolution.
2. Ultrasound is reflected very strongly on passing from tissue to gas, or vice versa.
This means that ultrasound cannot be used for examinations of areas of the body containing gas, such as the lung and the digestive system.
3. Ultrasound also does not pass well through bone
so that the method is of limited use in diagnosing fractures. It is possible to obtain quite good ultrasound scans of the brain, but much greater detail is obtained by an MRI scan.