Site Planning for a Mobile MRI Machine

A Mobile MRI machine intends to provide high system performance standards, comfortable patient handling, professional working environment, and sufficient storage space. Just like site planning for fixed MRIs, proper site location and preparation are still imperative for successful operation. Other requirements to keep in mind including support pad, electricity, mobile grounding, telephone and data service, water supply, site clearance, and general regulations.

Location. When choosing a location for the mobile MRI machine, think of the setting and how it will affect the set up. For example, consider the impact of the magnetic field to the surrounding areas such as buildings and parking lots, the ventilation for generator airflow, and the effect of moving metal and vibrations. Keep in mind that moving metal objects near the magnet, such as high power lines, emergency vehicles, forklift trucks, helicopter landings, and automobile traffic can affect magnetic field homogeneity and degrade

image quality. These objects should be held 9 to 12 feet from the unit. A firm, level surface is also required around the mobile unit for convenient access to the trailer, servicing the unit, proper handling of cryogens, and for patient lift operations and staircase.

Support Pads. Whether you choose the minimum support pads or the recommended full pad, the support pad level is strictly enforced to avoid any difficulties in the MRI system operation. The support pad depth should be determined by a local contractor based upon weight distribution. As there are varying site conditions and local building codes, the actual pad design should be prepared by a licensed structural or architectural engineer. It is also suggested that non-ferrous reinforcement materials be used for pad reinforcement.

Electricity. Electricity is essential in order to power the Mobile MRI machine, HVAC system, and the chiller. The trailer’s electrical system is hardwired on one end, and the free end of the cable has a connector attached for compatibility with the site’s receptacle, typically a 480 volt, 3-phase receptacle. The facility is responsible for providing a matching receptacle. As for connection of shore power, this should be performed by local, qualified electricians only. The shoreline is located in the rear skirt compartment and can be accessed from either the roadside or curbside. If power is lost to the unit, it is imperative that the generator be started to retain environmental controls.

Grounding. The ground for the system should originate at the first access point of power into the facility, and be constant to the system power disconnect in the room. The ground wiring consists of copper wires the same size as the disconnect feeders. The unit must also have an earth driven ground rod within a certain distance of the hospitable power receptacle. A grounding cable must be connected between the grounding rod and the grounding pin of the power receptacle. A separate insulated grounding conductor should also be installed in the power distribution unit in accordance with local, state and national electric codes.

Telephone and data service. The mobile MRI units are supplied with telephone connections, data line connections, and connecting cables; and the customer is required to purchase and install the weatherproof phone outlets for use at the site. Any additional cables needed must also be purchased by the customer. Telephone and data services may vary, so be sure to confirm exact connections on the trailer. For example, the data line may require a standard RJ45 connector mounted in a weatherproof box, and phone lines may require a Hubbell PH6597 weatherproof outlet mounted in a Hubbell PH6619 weatherproof box. Data boxes and phone boxes should be located in the same general area.