**3.3. Pre- screening and screening forms**

**3.2. MRI suite design and zones**

the MRI suite and patient safety.

from the detector (Shellock and Crues, 2004).

MRI suite.

zones suggested by the various articles are as follows;

An MRI suite should be designed to restrict access and limit exposure to static magnetic fields. Various publications have provided different designs to the MRI suite to ensure max‐ imum safety and they all showed that an MRI suite should be built to restrict access by zones (Gould 2008; Kanal *et al.,* 2007; Junk and Gilk, 2005; Shellock and Crues, 2004). The

58 Imaging and Radioanalytical Techniques in Interdisciplinary Research - Fundamentals and Cutting Edge Applications

Zone I: - Opens to the general public and presents the least exposure to the patients, staff and visitors. Usually it is the reception and waiting room for the MRI suite purposed to channel patients and medical staff to the pre-screening area (zone II) and limit entry to the

Zone II: - This is the first interaction site for patients, visitors and staff in the MRI suite. The purpose of this zone is to restrict further public access to the suite and provide direct super‐ vision of patients and visitors by the MRI staff. Pre-screening of all patients, staff and visi‐ tors also takes place here. If ambulatory, the patient is screened through a ferrous metal detector installed into the zone II. Non ambulatory patients in walkers, wheelchairs or pa‐ tient support need the transport equipment to be verified as MRI- safe or exchanged for MRI- safe equipment. The zone II generally has a metal detector and a 1000 gauss magnet to help screen medical equipment for ambulatory patients. MRI staff including the MRI tech‐ nologist is directly responsible for enforcing strict adherence to the MRI safety protocols for

Zone III: - This is the entry zone to the MRI machine room which is zone IV. Entrance to this zone is restricted physically and by protocol. Being the last barrier against an incident or in‐ jury due to an interaction of a static or active magnetic field and any unscreened personnel, patient or equipment, only MRI technologist, certified staff and pre-screening attending physician accompany the patient into the MRI machine room. The portal or entrance to the MRI machine room must be monitored by a second ferromagnetic- sensitive detector and door must be locked. Sounding of detector will require verification of either an MRI- safe or compatible event or the discovery of an MRI–unsafe condition in the patient, transporting or medical equipment or the attending medical staff. The standard access method is a card ac‐ cess system which should allow access to only certified MRI staff between zone III and zone IV. All medical staff must be pre-screened prior to entry into zone III to make sure no unscreened individuals will be allowed access to zone IV. Ideally, the personnel in zone III must be uniformed in MRI compatible scrubs which will avoid the use of identification badges in the suite, MRI-safe shoes and undergarments. Personnel must avoid all jewellery, watches metallic writing instruments, and wire-framed glass which may raise a false alarm

Finally in zone IV, the MRI room should have a clear demarcation of the five gauss line tap‐ ed or painted on the MRI suite floor to indicate the area beyond which requires MRI- safe or MRI – conditional equipment or instrumentation. This should be in line with the distance and tesla rating of the MRI. Zone IV should be clearly marked with a red light and lighted sign stating, "The Magnet is on." In situations where an alarm goes off for a code red, there Shellock and Crues (2004) emphasized that the establishment of thorough and effective screening procedures for patients and other individuals is one of the most critical compo‐ nents of a programme to guard the safety of all those preparing to undergo MR proce‐ dures or to enter the MR environment. All preliminary patient history, MRI safety screening and documentation must be completed and signed by the patient, guardian or clinician before procedures are undertaken on patients (Shellock and Crues, 2004; Ferris *et al.,* 2007). Various screening forms are used for different categories of people who come to the MRI suite. In general, screening forms are developed with patients in mind (Sawyer-Glover and Shellock, 2002).
