Design for Radiology in Your Equine Practice

Equine medicine currently is undergoing rapid advancements in the technologies available for diagnosis and treatment of disease. Diagnostic imaging equipment requires special design coordination, and the more specialized the equipment, the more architectural and engineering parameters must be accommodated. Designing imaging spaces correctly is critical for protecting the safety of your team and your patients, protecting the equipment itself, and producing the highest quality images. This article will focus on the unique design requirements for the most common imaging modalities. 

The field of radiology evolved from radiography, which originally focused on X-rays for diagnosis. Today, there are five primary modalities within radiology. These include ultrasound, X-ray, CT, MRI and nuclear medicine. There are treatment modalities as well, such as interventional radiology and radiation oncology, but these are most common in human medicine, small animal medicine, and in a limited capacity in equine medicine. This article will focus specifically on the use of ultrasound, X-ray, CT and scintigraphy. 

Designing for Ultrasound 

The design considerations for ultrasound focus on creating good images and protecting the equipment.  

• The space should be quiet and out of the hospital’s traffic flow so that your equine patient is calm. This is true for any imaging suite. 
• As with all equine exam spaces, you will need adequate room. Sixteen-foot clear in every direction is an accepted minimum. The common size for an exam room for ultrasonography is 18 by 24 feet. 
• Dimmable lighting can be helpful for better viewing of the ultrasound screen. 
• A convenient sink is recommended for cleaning up gel and cleaning and sanitizing the transducer(s) after a procedure. 
• Some cabinets are recommended for storing items you will need on hand. 
• Ultrasound equipment is expensive, so we recommend designing the space with a convenient, lockable equipment storage closet or room. The ultrasound cart should not be free to roll around the room where it might be damaged by collisions or water.  

Designing for Portable Digital X-ray 

This is the basic equipment that all equine veterinarians use. While this equipment is simple, it still emits ionizing radiation; therefore, follow all the regulatory requirements for protecting your team.  

• Provide lead blocks for the images; provide lead aprons, gloves and thyroid collars; and ensure that the space where the X-ray is used is large enough for other teammates and patients to stay outside of the range of the radiation.  
• Be aware of relative risk; radiation exposure for the person holding the cassette is significantly higher than for the person holding the handheld generator¹. 
• Portable X-ray equipment does not require that the room be provided with lead shielding; however, think ahead about where you will be using this equipment. For example, if you are taking images just on the other side of a partition where people are working, relocate radiography to an unoccupied area.   

Designing for Overhead X-ray, CT, and Scintigraphy 

Larger machines are completely different from portable machines. As we discuss these technologies, we will introduce three concepts that are common to all large diagnostic equipment: 

• Involvement of the manufacturer; 
• Shielding requirements; and 
• Infrastructure requirements 

If you are purchasing any large imaging equipment, do your homework. Talk to your colleagues, visit universities and large referral facilities, and ensure that there is a market need for this machine in your location. Check the references for the manufacturer¹ and ensure that your colleagues have had a good relationship for product quality, support during installation and service.  

Involvement of the Manufacturer  

Once you are ready to proceed, the manufacturer should be heavily involved to help your team with the logistics of sale or lease and installation, infrastructure and design requirements. They also should be ready with ongoing support, software and maintenance for the machine. The manufacturer will also need to provide information to your design team.  

(Author’s note: When we use the term manufacturer, we are oversimplifying to mean the company from whom you purchase the equipment. This company may not be the entity that makes the equipment, but they are the ones who will make the sale and who will provide you with the necessary information and technical support.) 

Shielding Requirements  

Shielding is required for overhead X-ray, CT and scintigraphy equipment. The amount of shielding required is dictated by a nuclear physicist, who will need the following information to produce calculations and a report: 

• The size and planned construction materials of the room. 
• Uses on the other side of the walls of the room. For example, if the room is adjacent to an office, there might be more shielding than if the room is adjacent to a storage area. 
• The location of the equipment within the room. If the machine is gantry mounted, the physicist will run calculations at the farthest extensions of the gantry. 
• The number of images you will be taking. This should be calculated for when you are at full capacity for your anticipated patient imaging load. 
• The equipment specifications. 

The physicist will then run a report that recommends construction and/or shielding of the walls to ensure that the ionizing radiation is contained within the room. This is required to be on file for your risk management and to comply with your state laws. The shielding report must be in place before your walls are constructed, if you wish to avoid expensive retrofits. The report might not recommend lead shielding. If your walls are constructed from concrete, they might offer enough shielding without the use of lead. 

Special Notes Regarding Shielding for Scintigraphy  

The isotope used for scintigraphy has a short half-life. However, the horse that has been administered the isotope will be “hot” for a period of time. Urine will be radioactive, and this material must be handled carefully. Hospitals providing scintigraphy equipment need the following: 

• A hot lab, which is specifically designed for the safe handling and delivery of the isotope. 
• A hot stall (or two) for equine patients to reside in until the isotope has acceptably decayed and the horse is no longer emitting radioactive waste. 
• The plumbing for these spaces and imaging room cannot connect to a city sewer, or to an on-site septic. Floor drains, if used, must feed into a collection area that allows the isotope to decay properly. As such, floor drains are problematic and need careful design. 
• Alternatively, bedding might be used to soak up urine. All urine, bedding, feces and any other material exiting the scintigraphy suite must be held and disposed of properly. 

Work very closely with the manufacturer and regulatory agencies to ensure your full understanding of the safe design and operation of a scintigraphy suite.  

Infrastructure Requirements  

We will outline the basics of all the parameters you and your design/construction team should be aware of. Specific requirements must be obtained by each machine’s manufacturer. 

• Room Size and Layout Fundamentally, each large machine requires very specific room sizes and layouts. Before you decide to purchase a machine, perform a quick study to lay out the machine in an existing or new space so you know how much area it will require and so you can plan how the imaging room will be accessed, particularly if it needs hoist access. The imaging equipment should be placed in a quiet area of the hospital and sound controlled so that the horse will remain calm for sedated procedures and to allow the team to concentrate while taking images.   
• Structural Requirements Each large machine has specific structural requirements. For machines with overhead mounted gantries, the columns for these must be securely bolted to foundations. For machines that require hoist access, the bottom of the trolley beam should be set at 15 feet above the finished floor. This is to ensure that when the horse is hoisted, its head does not drag on the floor. In the case of CT equipment, the height is needed to place and position the horse on top of the table (couch) that enters the CT machine. If this height is not possible, then work very carefully with the equipment manufacturer to ensure that you find a solution prior to proceeding. 
• Some CT machines also require the construction of a pit. The pit and the entire slab for the room need precise coordination and construction to ensure proper functioning of the machine.  

Mechanical Requirements  

Large imaging equipment has precise temperature and humidity parameters to protect the function and longevity of the equipment. In addition, scintigraphy rooms require air exhaust. It is likely that you will need separate mechanical systems to serve the imaging suite(s). Employ a mechanical engineer, who should obtain the manufacturer’s requirements. Do not rely on a contractor to “design/build” an imaging room—the equipment is too expensive for an informal approach to mechanical design. 

Electrical Requirements  

We have saved the most complicated infrastructure for last. Before you decide to purchase imaging equipment, an electrical analysis must be conducted for your site. It is very likely that your site will not have the power necessary to run a new diagnostic imaging machine, and you might need a new electrical service. Electrical upgrades should be budgeted from the beginning as they can be expensive. Large machines often require high-quality power. The power cannot flicker and brown out. Three phase (instead of single phase) power is generally required, and you might also want to consider a backup generator.  

The largest challenge left in supply chain disruptions is long lead times for electrical equipment and utility service. Obtaining electrical equipment and service regularly takes 12 to 18 months throughout the U.S. and Canada. Electrical equipment and service should be ordered as early as possible in the design. Therefore, you will need a contractor on board early. 

Power service, outlet placement, emergency shut offs, data locations, conduit placement (and shielding thereof, if relevant), and lighting can be complicated to coordinate. The electrical drawings should be completed by an engineer, and this engineer should have their drawings reviewed by the equipment manufacturer prior to construction.  

Take-Home Message 

In summary, design for imaging technology is technically complex. Portable equipment requires some thought and planning, and large equipment takes a village. However, assuming the market is strong in your area, the practice’s potential for better patient care is worth the effort.

Reference 

1. Ellis, Katherine L., et al. Radiation Exposure to Personnel Obtaining Equine Appendicular Radiographs Using a Handheld Generator. Journal of Equine Veterinary Science, Vol. 73, Feb. 2019.