A very common question from breeders thinking about making an ultrasound machine a permanent fixture in their breeding programme, or for those thinking of setting up a scanning business, is "is ultrasound safe?"

No adverse effects of ultrasound use have ever been reported in the clinical setting, which is a pretty strong reference given that ultrasound examinations have now been routinely carried out for over 30 years on the most vulnerable of patients, particularly foetuses. With the constant advances in the power of machines and the number of functions available, however, some believe it is theoretically possible for tissue damage to occur through thermal or mechanical cell damage at some point in the future as we push the boundaries of what we can achieve with ultrasound further and further.

A paper by Hlinomazova and Hrazdira apply the ALARA (As Low As Reasonably Achieveable) to ultrasonography, making the following recommendations for ensuring patient safety:

- Always use a transducer of the appropriate type and frequency.

- Keep power output at the lowest possible setting necessary to product an image.

- Adjust the focus to the area of interest

- Keep the transducer moving - avoid holding the probe stationary in one area for a prolonged period of time.

 

All of the above recommendations are in line with 'common sense' good practice scanning methods, as taught on our ultrasound courses. They are also all achievable with the machines which we stock; all of our ultrasound scanners allow focal points to be set, and scan time can be minimised by taking advantage of the cine loop function. Cine loop allows you to perform your scan, and instead of holding your probe over an area of interest for an extended period (to look more closely or to show a client), you can simply press the 'freeze' button and then rewind back to the area of interest.

In addition, by following our course recommendations of performing scans at or after the 30 day mark, the patient is further protected. Foetuses at the earliest stages of gestation are most vulnerable to thermal damage, as they are too underdeveloped to be able to regulate their own body temperature in any way.

Perhaps the biggest danger of ultrasound scanning is not the actual ultrasound waves themselves, but the risks associated with rough probe handling or stress on the animal. Animals that need to be examined internally for pregnancy (such as a cattle) are at particular risk, which is why performing internal examinations is strongly restricted by law and requires a legal exemption, only obtainable by attending a DEFRA-approved ultrasound course. Again, by following good scanning technique, these dangers are easily avoided.