Radiography is an excellent way to view most bony structures and some soft tissue structures. Xrays produced by the radiography machine are absorbed at varying rates by different tissues, this absorption results in different levels xrays reaching the plate placed behind the object required to be imaged. The fewer xrays that reach the plate the whiter the image. As bone absorbs xrays better than soft tissue bone appears white and soft tissue shades of grey.
The ultrasound probe works by sending out a certain frequency of wavelength and then records the time taken for the signal to be bounced back. As a result of this ultrasound gives very good soft tissue imaging and is especially good for tissues with a higher water content. The ultrasound machine then converts this data into a 2D image. The quicker the signal returns to the probe the darker the image produced. Ultrasound can be used to image the external surface of bones and is especially useful where radiography is difficult to perform - such as some pelvic fractures. The majority of scanning work performed by the clinic is either reproductive work or tendon scans.