One of the reasons ultrasound is gaining wider and wider usage as an imagine technique is because it is very safe compared to other techniques like x ray imaging. This doesn’t mean, however, that it doesn’t have its dangers if misused. The danger, if any, seems not so much to be from misuse but overuse. As is the case with many other things, too much of a good thing can cause it to stop being so good.
The job description “diagnostic ultrasound technician” covers a large portion of work that is done in the field. The imaging that is used in ultrasound is used much of the time to try to diagnose problems or potential problems. True it is often used to discover the sex of unborn babies and to phacoemulsify cataracts to make way for lense implants, but the rest of the time it is used to explore and monitor the human physical system. In all cases, however, there is one common denominator – the safety of the patient comes first.
So is ultrasound safe or unsafe? There is, in fact, some debate here. Studies on laboratory mice have shown some cellular effects such as slowed cell division and increased cell death to be correlated with prolonged ultrasound. A few other studies have found connections between ultrasound, particularly large amounts of it, with decreased birth weight. There was even a Canadian study that found children with delayed speech learning to be twice as likely to have received ultrasound as those that did not.
The flip side is that many other studies show no such connections, and the general party line in the industry seems to be that there are, basically, no ill effects from the use ultrasound. The World Health Organization recognizes ultrasound as generally safe. To quote them: “Diagnostic ultrasound is recognized as a safe, effective, and highly flexible imaging modality capable of providing clinically relevant information about most parts of the body in a rapid and cost-effective fashion.” But then again, we’ve seen enough scams, scandals, and conspiracies by now to take such sweeping statements with at least some caution these days, haven’t we?
But what about the actual physics of the ultrasound process itself? Unlike x radiation, sound waves are non-ionizing. That means they have no appreciable effect on the charges of the compounds that make up cells. Ionizing radiation does have an affect on charge – it is powerful enough to break electrons off of atoms and molecules and this can cause cell damage rannging from minor to major. This takes the form not only of electromagnetic radiation at certain frequencies and energies but also of alpha and beta particles or neutrons colliding with cells. It is this kind of radiation that at high levels is associated with cancer. It is what most people are talking about when they refer to the “harmful” type of radiaiton.
But ultrasound is not of this type, so why the concern? Ultrasound is very fast sonic vibration – usually at millions of Hertz (cylces per second) – and as such it generates some heat and pressure. The greatest concern seems to be in the case of prenatal infants – they are at such a delicate stage of development that this extra intracellular heating may be undesirable or potentially cuase problems.
Some are far more militant about this entire issue than others. Many dismiss the claims that ultrasound is dangerous as a silly overraction, while others assert that the information generally disclosed in the industry is not 100% truthful and thorough, and that there are indeed significant dangers associated with sonography. It is thus, hard to get a very distinct picture regarding safety. But it seems clear enough that, especially as regards prenatal ultrasound, it should only be undertaken when really necessary, and by trained professionals. There has been a wave of interest in ultrasound in an almost “recreational” sense i.e. in order to simply take pictures of the unborn baby or determine whether it is a boy or a girl. This practice, and repeated ultrasound when there are no problems that clearly need diagnosis or monitoring, are to be discouraged. It is better to be on the safe side with this, since there is debate about ultrasound effects.
Below are some sites that discuss the issue, and anyone concerned, be they diagnostic ultrasound technicians or parents-to-be should read them and other articles in order to get a sense of both sides of the debate concerning this issue. Ultrasound is clealry safer than some other types of imaging, but that doesn’t mean anyone involved in or considering its use shouldn’t educate themselves about the safest means of going about it. It’s important to use any type of technology responsibly rather than making assumptions about it. Safety is not the type of issue that should be left to chance or ignorance.
Links: