## 4 Case Study 2  
### Case Study Context and Goal of the Analysis  
The second case study concerns the analysis of the current management of a room where an MRI machine is used for patients' diagnoses in an Italian public hospital. MRI is a widespread non-invasive diagnostic technique thanks to its ability to obtain high-quality two-dimensional and three-dimensional images of the human body. The rapid technological development that has affected this sector has brought increasingly powerful and complex devices to the market, which has seen the affirmation of tomographs with superconducting magnets. However, this system requires considerable quantities of cryogenic liquids, the leakage of which, in a confined environment such as the MRI room, can cause severe effects on the health and safety of both patients and operators. The risks associated with the massive use of cryogenic substances have led to the issue of specific safety parameters concerning the structural and plant requirements (i.e., the MRI room), as well as the device itself [66]. Patients and operators working near the equipment are exposed to several hazards related to the MRI environment, which are due to the presence of three types of magnetic fields simultaneously: static magnetic field, time-varying magnetic field gradients, and radiofrequency (RF) magnetic field. More in detail, following the study by [PERSON] et al. [67], the main risks related to the use of this device can be summarized as follows:  
1. Projectile effect: Magnetic fields can attract objects toward the magnet, posing dangers to both patients and operators. The static magnetic field is conventionally categorized into two zones: Zone 1 (close to the magnet's center) and Zone 2 (surrounding the magnet with decreasing magnetic intensity). Ferromagnetic objects in the former area are subject to torsion, and if the object is inside the patient's body, it can potentially cause tissue damage. In the latter, ferromagnetic objects are also subject to a translational force, leading to the \"projectile effect,\" where these objects can be rapidly drawn into the magnet, potentially leading to injury or damaging the magnet. Several accidents are reported, which have involved the presence in the room of oxygen and helium cylinders, cleaning trolleys, metal chairs, scissors, etc. [68]. 2. Twisting: this effect is due to the deflection or torsion of magnetic objects, such as vascular clips and cochlear implants, that can lead to incorrect implant functioning or cause damage to patients. Besides these risks, other negative effects on the patient's and operator's health can be due to the RF field (which can lead to tissue heating) as well as the magnetic field gradients (which can lead to peripheral nerve stimulation and implant heating). The latter can also cause abnormal noise in the MRI scanner room that can lead to hearing damage [69]. To prevent these hazardous situations, the use of an MRI room is subject to strict safety requirements worldwide, where the Italian situation differs due to stricter regulations than the European Union ones [70]. Based on these safety requirements, the hospital issued an internal regulation that includes the use of a questionnaire that has to be filled out by the patient and checked by the MRI room manager before the patient is allowed to access the room for the diagnosis. Actually, the involuntary introduction of ferromagnetic objects into the MRI room or the entry of subjects with life-saving implantable medical devices has to be avoided. Hence, since the MRI room access represents a high-risk activity, we decided to analyze the procedures for accessing the MRI room by means of FRAM in order to identify where functional resonance phenomena could emerge and spread. It has to be noted that the MRI room is located inside a Controlled Access Zone (ZAC). Hence, the MRI unit consists of an acceptance zone, the ZAC, and the MRI room.