(49 days)
The MAGNETOM SYMPHONY with the Sonata Gradients is a whole body scanner with higher gradient amplitudes. The MAGNETOM SYMPHONY with the Sonata Gradients is indicated for use as diagnostic imaging device to produce transversal, sagittal, coronal and oblique images of the internal structures of the head or body. The images produced by the MAGNETOM SYMPHONY with the Sonata Gradients 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 (T") and flow. When interpreted by a trained physician, these images provide information that can be useful in determining a diagnosis.
The MAGNETOM SYMPHONY with the Sonata Gradients is a whole body scanner with higher gradient amplitudes.
The Siemens Medical Systems, Inc. Sonata Gradients for the MAGNETOM SYMPHONY System is a Magnetic Resonance Diagnostic Device. The provided text outlines the safety and effectiveness testing conducted to support its substantial equivalence to the commercially available MAGNETOM Symphony System.
Here's an analysis of the acceptance criteria and study as requested:
1. Table of Acceptance Criteria and Reported Device Performance
The provided 510(k) summary mentions several safety and performance levels that were evaluated, using the FDA guidance document for MR Diagnostic Devices. It largely focuses on demonstrating that the new Sonata Gradients do not significantly change these levels and remain below levels of concern.
| Category | Acceptance Criteria (Action/Performance Level) | Reported Device Performance |
|---|---|---|
| Safety | Maximum Static Field | Not significantly changed; remains below the level of concern. |
| Rate of Change of Magnetic Field (dB/dt) | Not significantly changed; remains below the level of concern. | |
| RF Power Deposition | Not significantly changed; remains below the level of concern. | |
| Acoustic Noise Levels | Not significantly changed; remains below the level of concern. | |
| Performance | Specification Volume | Not explicitly detailed, but implied to be acceptable. |
| Signal to Noise | Not explicitly detailed, but implied to be acceptable. | |
| Image Uniformity | Not explicitly detailed, but implied to be acceptable. | |
| Geometric Distortion | Not explicitly detailed, but implied to be acceptable. | |
| Slice Profile, Thickness, and Gap | Not explicitly detailed, but implied to be acceptable. | |
| High Contrast Spatial Resolution | Not explicitly detailed, but implied to be acceptable. |
Note: The document explicitly states that for safety parameters, the new levels are "not significantly changed and, in the case of safety, parameters remain below the level of concern." For performance levels, it generally implies that the system's performance remains acceptable without providing specific numerical thresholds or results. This is common for 510(k) submissions focusing on substantial equivalence, where the primary goal is to show the new device is as safe and effective as a predicate, rather than establishing absolute performance benchmarks.
2. Sample Size Used for the Test Set and Data Provenance
The document states, "Laboratory testing were performed to support this claim of substantial equivalence and to show that the technological differences do not raise any new questions pertaining to safety and effectiveness."
- Sample Size for Test Set: Not specified. The document refers to "laboratory testing" which typically involves phantom studies and perhaps limited human volunteer scans for an MRI system. No patient-specific test set size is mentioned.
- Data Provenance: Not specified. Given it's "laboratory testing," it would be internally generated data during development and verification, likely in the United States (where Siemens Medical Systems, Inc. is located for this submission). It is a prospective evaluation as it's testing the new device.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
Not applicable. The study described focuses on technical performance parameters of an MRI system (e.g., field homogeneity, signal-to-noise ratio, acoustic noise) rather than diagnostic accuracy or clinical interpretation. Therefore, there is no mention of experts establishing a diagnostic ground truth for a test set of images. The "ground truth" for these technical parameters would be established through calibrated measurement equipment and engineering standards.
4. Adjudication Method for the Test Set
Not applicable for the reasons stated above. The evaluation is of the system's physical and technical characteristics, not the interpretation of medical images by human readers.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No. An MRMC study was not conducted or reported. The study focuses on the technical specifications and safety aspects of the MRI system with new gradients, not on its comparative diagnostic effectiveness with human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, in a sense. The "laboratory testing" described is a standalone evaluation of the device's physical and technical performance. The MRI system itself, with its new gradients, is the "algorithm only" in this context, demonstrating its technical capabilities without direct human interpretive input being measured as an outcome.
7. The Type of Ground Truth Used
The ground truth used for this type of evaluation is primarily physical measurements and engineering standards. For example:
- Physical measurements from probes and sensors for static magnetic field, dB/dt, RF power deposition, and acoustic noise levels.
- Measurements using phantoms (standardized test objects) for specification volume, signal-to-noise ratio, image uniformity, geometric distortion, slice profile, and high contrast spatial resolution.
- Compliance with pre-defined technical specifications and safety thresholds.
8. The Sample Size for the Training Set
Not applicable. This is not a machine learning or AI algorithm submission that would require a separate training set. The "device" here is a hardware component (gradients) for an MRI system.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set mentioned or implied for this submission.
§ 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.