Читать книгу Essentials of MRI Safety - Donald W. McRobbie - Страница 45

Along with an understanding of MRI hardware and fields it is important to understand how these interact with other medical devices. A system to categorize the MRI safety (we used to say “compatibility”) of other devices: implants, accessories, medical equipment, tools, fire extinguishers, gas tanks, etc. uses three labels [6]:

 MR Safe means that the device poses no risk to the patient in the MR environment. Image quality may be affected.

 MR Conditional means that the device poses no additional risk to the patient when introduced to the MR environment under specified conditions.

 MR Unsafe means that the device may not be introduced into the MR environment as it poses significant risk to the patient and/or staff.

The approved signs are shown in Figure 1.29. The “MR environment” generally means the MR examination room, or areas with a fringe field exceeding 0.5 mT, rather than just the scanner itself. The safety of implants is considered in Chapters 9–11.

Figure 1.29 MR device labeling according to ASTM‐F2503 (IEC‐62570) [6]. The two MR Safe symbols are equivalent; either may be used.