Anesthesia-compatible Magnetic Resonance Imaging

In Reply:—

We appreciate the interest of Miyasaka et al. in our recent letter¹ and applaud them for their comments.

Miyasaka et al. demand the development of anesthesia-compatible magnetic resonance imaging (MRI) suites and monitoring techniques because conditions to provide anesthesia for patients in MRI suites are often far from optimal and provoke mistakes.

In particular, the authors address difficulties achieving adequate monitoring within the MRI suite, especially in critically ill patients. Clearly, the problem is that monitors, ventilators, and infusion pumps either interfere with the MRI (evoking low quality images or artifacts) or the equipment contains ferromagnetic parts and may not work correctly in the presence of a strong magnetic field (which results in danger for the patient). At the same time demand for MRI diagnostic procedures in critically ill patients is increasing steeply. Thus, with present equipment the anesthesiologist often faces a “catch-22” situation.

Accordingly, Miyasaka et al.'s points that MRI manufacturers should take anesthesiologists‘ comments regarding more comfortable and safe MRI suites seriously and that anesthesiologists should be involved in conceptual designs of MRI suites from the beginning are well taken. However, even if MRI suites become more anesthesia-compatible in the future, the main risk, i.e., the presence of a very strong magnetic field with all its hazards, as reported in our letter, is inescapable.

Furthermore, their well-taken comments do not only apply to MRI suites. In the near future, some operating rooms and advanced shock/trauma patient admission units will contain MRI equipment. Thus, the need for more high-tech MRI-safe ventilators and monitors in the future is obvious, and, as always, anesthesiologists should take part in developing and shaping their future work environment.

Christian Zimmer, M.D.,*

Markus N. Janssen, M.D.

Tanja A. Treschan, M.D.

Jürgen Peters, M.D.

* Klinik für Anästhesiologie und Intensivmedizin, Universitätsklinikum Essen, Essen, Germany. [e-mail]