I would like to start by saying that I am sorry for having disappeared for the past couple of months due to exams and UCAS, but hopefully I can write more often now .
On my recent work experience at BRI I was fortunate to be able to shadow a sonographer and so thought I’d share my experience.
Ultrasound is a form of energy using high frequency soundwaves to produce an image. During my time in ultrasound many abdominal cases and a madible case was seen. These involved gall stones, mass, focal lesions and lymph node in the mandible.
A gel medium was required in order to improve transmission of soundwaves. The speed of this sound varies depending on the medium density and compressibilty. Without the gel the soundwaves would have to travel through different densities; through air and then through soft tissue.
Even though ultrasound does not give off radiation, it still may not be as safe. The bioeffects of ultrasound are heating and cavitation. The beam is attenuated as it passes through tissue therefore energy is lost. This energy is absorbed and converted into heat. This can cause over heating of any microbubbles which may be present within organs. Changes in pressure of the beam may cause the microbubbles to oscillate in size and cause tissue damage. However, ultrasound has not yet been proven to be unsafe.
Ultrasound soundwaves cannot pass through bone so only the outer surfaces of bones will be shown, and what is within the bony structures will not be shown. Another limitation is large body habitus and if there is more gas than bone present. Because of these limitations other modalities such as CT, general X-RAY and MRI have to be used.