(78 days)
The MR system is an imaging device, and is intended to provide the physician with physiological and clinical information, obtained non-invasively and without the use of ionizing radiation. The MR system produces transverse, coronal, sagittal, oblique, and curved cross-sectional images that display the internal structure of the head, body, or extremities. The images produced by the MR system reflect the spatial distribution of protons (hydrogen nuclei) exhibiting magnetic resonance. The NMR properties that determine the image appearance are proton density, spin-lattice relaxation time (T1), spin-spin relaxation time (T2), and flow. When interpreted by a trained physician, these images provide information that can be useful in diagnosis determination.
The STRATIS / MRH-1500 Operating System Software is modified to change the maximum SAR limit from 0.4 W/kg to 1.0 W/kg as permitted under the International Electrotechnical Commission (IEC) standard Part 2: Particular Requirements for the Safety of Magnetic Resonance Equipment for Medical Diagnosis.
This document details a 510(k) premarket notification for a modification to a Magnetic Resonance (MR) diagnostic device. The primary change is an increase in the maximum Specific Absorption Rate (SAR) limit from 0.4 W/kg to 1.0 W/kg, aligning with the International Electrotechnical Commission (IEC) standard Part 2: Particular Requirements for the Safety of Magnetic Resonance Equipment for Medical Diagnosis.
The document does not detail a study involving human or animal subjects that would typically have acceptance criteria for device performance in a diagnostic context (e.g., sensitivity, specificity, accuracy). Instead, the "acceptance criteria" here refer to compliance with safety standards for SAR levels.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Safety Standard) | Reported Device Performance (SAR Limit) |
|---|---|
| FDA Guidance (prior to IEC adoption): |
§ 892.1000 Magnetic resonance diagnostic device.
(a)
Identification. A magnetic resonance diagnostic device is intended for general diagnostic use to present images which reflect the spatial distribution and/or magnetic resonance spectra which reflect frequency and distribution of nuclei exhibiting nuclear magnetic resonance. Other physical parameters derived from the images and/or spectra may also be produced. The device includes hydrogen-1 (proton) imaging, sodium-23 imaging, hydrogen-1 spectroscopy, phosphorus-31 spectroscopy, and chemical shift imaging (preserving simultaneous frequency and spatial information).(b)
Classification. Class II (special controls). A magnetic resonance imaging disposable kit intended for use with a magnetic resonance diagnostic device only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.