There are many variables involved in the production, detection and treatment of 
ultrasound data, which are, for the most part, under the control of the operator.Gives direct vision for biopsies 
Some problems with ultrasound imaging are that the diagnostic images sometimes 
cannot be obtained because of the size of the patient, or because the ultrasound 
beam cannot navigate the areas of air-filled or bone in such cases, the crosssectional imaging with CT or MRI can be used instead.All 
the different imaging techniques, ultrasound is the most affected by the skill and 
experience of the operator, both in the acquisition and interpretation of images.Diagnostic ultrasound offers advantages over other imaging modalities, and the 
most important of these advantages do not use ionizing radiation, making it safer, 
especially in imaging during pregnancy.After the first use of ionizing radiation (x-ray) by Roentgen in 1895 to 
visualize the interior of the body has been the only way for decades.The other important feature is its ability to 
image in real time, making it simple to perform live active and passive range of 
motion studies, in addition to the low cost.However, 
during the second half of the twentieth century was the discovery of new imaging 
methods are quite different from those of the X-rays.Was one of the most 
important of these ways is ultrasound, which showed the particular potential and 
greater benefit of imaging which relies on X-rays.In summary, the feature of ultrasound:
?Uses no ionizing radiation 
?Minimal preparation of patients 
?Inexpensive 
?Portable 
?Painless 
?Medical treatment can be given after a proper diagnosis or identify the disease 
properly.Safe in pregnancy 
?Has no known side effects 
?