Читать книгу Essentials of MRI Safety - Donald W. McRobbie - Страница 44

The IEC standard 60601‐2‐33 [4] defines three modes for scanning:

 Normal mode: mode of operation of the MR equipment in which none of the outputs has a value that may cause physiological stress to patients.

 First‐level controlled mode: mode of operation of the MR equipment in which one or more outputs reach a value that may cause physiological stress to patients which needs to be controlled by medical supervision.Software allowing access to this mode must require specific acknowledgement by the operator that the first‐level controlled mode has been entered.

 Second‐level controlled mode: mode of operation of the MR equipment in which one or more outputs reach a value that may produce significant risk for patients, for which explicit ethical approval is required (i.e. a Human Studies protocol approved to local requirements).

“Outputs” refers to the magnitude of the magnetic fields. Clinical scanners are usually restricted to the Normal and First Level Modes.