Canine Leptospirosis

Radiography is a cornerstone diagnostic in the veterinary field that is available at nearly every small animal practice. While the wide variety of uses and benefits of radiography are undeniable, it is not without risks, and improper usage can cause real harm to patients and staff. It is therefore critical to prioritize radiation safety to safeguard the health of both veterinary professionals and our patients. 

X-rays are a form of ionizing radiation and exposure increases the risk of cancer. Similar to sun exposure, risk increases with chronicity and intensity of exposure. However, unlike the sun, X-rays do not cause a sunburn when you overexpose yourself or a patient. At the levels used in veterinary medicine there is no immediate physical warning that you have been unnecessarily exposed. Even though the x-ray beam is directed at the patient, every exposure results in scatter radiation that exposes everyone and everything else in the room to a small dose of radiation. As the CDC states "even if it is a small dose, if receiving that dose has no direct benefit, you should try to avoid it.”1 It is therefore important to minimize risk by keeping exposure as low as possible by using the the principle of ALARA (As Low As Reasonably Achievable). 

Three main components to radiation safety that can be used to achieve the ALARA principle: reduce time of exposure, increase distance from the source of radiation, and use shielding to block radiation.

REDUCE TIME: this refers to the amount of time one is exposed to a radiation source. In the context of veterinary medicine, this means spending less time exposed to the active X-ray machine, and making sure every exposure generates a useful diagnostic image. Training staff on proper patient positioning and management will reduce the number of exposures. Sedation or anesthesia may be necessary to facilitate optimal positioning during radiograph acquisition, minimizing the likelihood of patient movement and the need for repeated exposures.

INCREASE DISTANCE: The further you are from the x-ray generator during radiograph acquisition, the safer you are. X-rays may be a powerful type of energy, but even the air in the room can diminish their power and therefore their risk.The strength of an x-ray beam is inversely proportional to the square of distance from the source. Therefore, if you double the distance of your body from the x-ray tube, the dose of radiation you are exposed to will be quartered. In practice, this means that even moving a very short distance from the tube will dramatically reduce the dose you receive. Optimally, all staff should be outside of the X-ray suite when exposing the patient, and this is required by some states and municipalities (Figure 4). If you have to be in the room with the patient, try to stay as far from the patient and x-ray tube as possible. Restraint devices such as sandbags, ropes, tape and E-collars can be used to hold the patient in place allowing personnel to step away from the patient or out of the room entirely. (Figure 1) 

USE SHIELDING: The simplest way to prevent x-ray exposure, is to block the x-ray before it hits your body. All x-ray rooms should be shielded to prevent x-rays from escaping into surrounding areas. Shielding plans are developed by specialized radiation physicists to be in accordance with local regulations. These plans are generated based on the type of x-ray equipment, the frequency of usage, and the occupancy and use of the spaces around the x-ray room.

In veterinary medicine, it is not uncommon for staff members to be within the x-ray room during radiograph acquisition. This requires the use of personal protective equipment to prevent unnecessary radiation exposure such as aprons, gowns, gloves, and thyroid collars (Figure 3). These shields serve as effective barriers, attenuating radiation and reducing the risk of radiation-induced health complications among veterinary personnel. It is recommended that personnel have access to multiple sizes of protective aprons and thyroid collars to ensure appropriate fit and coverage. (Figure 2) 

Traditionally, these protective body shields were made with lead, however, new composite materials and impregnated fabrics are now available that are equally as effective, but significantly lighter, less susceptible to breakage, and do not carry the risk of lead dust exposure. Some products are even machine washable, which is very useful in the veterinary setting.

Routine maintenance of protective equipment is important, especially for lead gowns and collars. The thin lead can crack with repeated use or inappropriate handling. Lead gowns should always be hung up and never crumpled or folded as this cracks the lead. These cracks are hidden by fabric, but can still allow x-rays to sneak through. Lead PPE material should be checked radiographically at least yearly to ensure no cracks are present. This should be performed more frequently if this equipment is used very