As ultrasound becomes more widely used in virtually every field of medicine, it is becoming a widely accepted technology that is capable of many tasks. Not only have ultrasound machine allowed researchers to develop new ways of gathering valuable diagnostic information, it has done so without exposing patients to harmful radiation. Finely tuned and targeted ultrasound beams have even been used in non-invasive surgeries and as a way of administering cancer drugs, but few people are aware of how it impacts the body.
In addition to measuring the depth and density of tissue by looking at a graphical image of sound waves, ultrasound scanners also create a mechanical energy that puts pressure on tissues. As the wave of pressure travels through tissue, it sends information back to the transducer which helps form an image.
Physically, the effects of ultrasound are categorized in the following ways.
· Thermal energy heats the tissue as ultrasound is absorbed
· The surface of the transducer produces heat at the skin’s surface
· Gas bubbles, also known as cavitations, are formed when there is a high level of negative pressure
· Mechanical effects of ultrasound may include streaming within fluids or stress where tissues come together
Ultrasound operators will be familiar with two indices, the thermal index (TI) and the mechanical index (MI). Each of these indexes measures the bio-effects of ultrasound machines and provides a clear measurement for the practitioner to read during testing. The most sensitive kind of ultrasound is one that examines a developing fetus or embryo.
FDA regulations specify the maximum intensity of spatial peak time by employing specific formulas, which help determine the thermal index. The danger of a higher thermal index (TI) is also determined by the type of tissue being examined and whether it is close to a bone. Simultaneously, the mechanical index (MI) is tracking the amplitude of the pressure pulse emitted by the transducer to determine the relative risk of pressure, including cavitation and streaming.
Technicians who are thoroughly trained on the device are able to conduct a diagnostic ultrasound test in a way that gathers the required information without compromising the safety of the patient.