(76 days)
The system enhancement package does not change the existing indications for the standard Outlook system as defined below.
The Outlook system is indicated for use as a NMR device that produces images that: (1) correspond to the distribution of protons exhibiting NMR, (2) depend upon the NMR parameters (proton density, flow velocity, spin-lattice relaxation time (T1), and spin-spin relaxation time (T2)) and (3) display the soft tissue structure of the head and whole body. When interpreted by a trained physician, these images yield information that can be useful in the determination of a diagnosis.
The Outlook System Enhancement Package includes changes in the computer subsystem, magnet subsystem, gradient subsystem, RF subsystem, patient handling subsystem, magnet enclosure and the power distribution subsystem. The package also includes additional imaging sequences and acquisition/reconstruction techniques. However, the basic features of the operating software are unchanged.
This document is a 510(k) premarket notification for a medical device called the "Outlook System Enhancement Package," which is an upgrade to an existing Magnetic Resonance (MR) Imaging System. This submission is for substantial equivalence to a predicate device, rather than a novel device requiring extensive clinical trials to establish its own efficacy and safety from scratch.
Therefore, the typical acceptance criteria and study design elements you've listed (like sample sizes for test/training sets, expert consensus for ground truth, MRMC studies, or standalone algorithm performance) are generally not applicable in the context of a 510(k) for an MRI system enhancement, especially one from 1998.
Instead, the "acceptance criteria" here are demonstrating substantial equivalence to a previously cleared device. The "study" proving this involves a direct comparison of technological characteristics and intended use.
Here's an breakdown based on the provided text, addressing your points where possible and clarifying why others are not present:
Acceptance Criteria and Reported Device Performance
The acceptance criteria for K974844 is demonstrating "substantial equivalence" to the predicate devices: the "Standard Outlook (K945827)" and the "Edge/Vista System Enhancement (K964626)".
The table provided directly within the submission serves as the "study" demonstrating this.
| Item | Outlook System Enhancement Package Acceptance Criteria (demonstrated by "Same" or improved features) | Reported Device Performance (Summary of how the new device meets/differs from criteria) |
|---|---|---|
| Intended Uses | Must not change existing indications for the standard Outlook system. | "The system enhancement package does not change the existing indications for the standard Outlook system." The device is still indicated for producing images corresponding to proton distribution and NMR parameters to display soft tissue structures for diagnosis by a trained physician. |
| Technological Characteristics | No new questions of safety or effectiveness regarding computer, magnet, gradient, RF, patient handling, magnet enclosure, power distribution, operating software, imaging sequences, acquisition/reconstruction techniques, coils, static/time-varying magnetic field, RF absorption, and acoustic noise. | The provided "SUBSTANTIAL EQUIVALENCE CHART" explicitly compares the Outlook System Enhancement Package to the predicate devices across 18 items. For many, it states "Same," directly demonstrating equivalence. For others (e.g., increased gradient performance, higher RF amplifier power, increased receive bandwidth, additional imaging sequences), it shows improvement or enhancement while maintaining similarity in overall function and safety. For example:Computer subsystem: Same display/database computer, Ethernet, DICOM 3.0 compliant. Enhancements include additional options, single reconstruction processor (vs 16 parallel), and additional hard disk.Magnet subsystem: Iron C-arm magnet, improved ramp-up time (6 min vs 10 min), increased magnetic field stability.Gradient subsystem: Increased gradient performance with active shielded design (vs 12 mT/m and 20 T/m/s shielded).RF subsystem: RF amplifier max average power 500 W (vs 250 W), receive bandwidth ± 100 kHz (vs ± 50 kHz).Operating software: Same.Imaging Sequences: Same with enhancements to Inversion Recovery and Fast Spin Echo sequences.Acquisition and Reconstruction Techniques: Same with addition of Read Conjugate Symmetry, TrueRes, Keyhole.Receive Only Coils: Similar range, with "Brain" coil added and "Body" coil becoming "Body/Spine."Static Magnetic Field: Same (0.23 T).Time Varying Magnetic Field: Same (Normal mode $\le 40$ T/s, First level controlled mode $\le 60$ T/s).Radiofrequency Absorption: Same (Normal mode $\le 1.2$ W/kg, First level controlled mode $\le 3.2$ W/kg).Acoustic Noise: Same (A-weighted average |
| Performance (Imaging Quality) | Maintain diagnostic utility comparable to predicate devices. | While not explicitly quantified with metrics like SNR or resolution, the claim of "enhancements" to imaging sequences and acquisition/reconstruction techniques (e.g., TrueRes, Keyhole) implies improved or at least maintained image quality. The primary evidence is the substantial equivalence in other technical specifications, suggesting the diagnostic output remains equivalent or better. |
Study Details (As applicable to a 510(k) for an MR System Enhancement)
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Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):
- Not applicable for this type of submission. This 510(k) is based on engineering comparison and performance specifications, not a clinical study involving patient data. There is no "test set" of clinical images or patient data to evaluate. The "test" is the comparison of technical specifications against predicate devices.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience):
- Not applicable. There is no "ground truth" established by experts for a test set in this type of submission. The ground truth for substantial equivalence is the technical specifications and performance of the predicate device itself, which was already cleared by the FDA.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable. No test set or expert adjudication process was described or required for this type of 510(k).
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If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- Not applicable. This is an MRI system enhancement, not an AI-powered diagnostic tool. MRMC studies are not relevant here.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. This is hardware and software enhancement for an MRI system, not a standalone diagnostic algorithm. The device's "performance" is its ability to acquire images, not interpret them. Interpretation is explicitly stated to be "by a trained physician."
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- Not applicable in the conventional sense. The "ground truth" for this submission is the established safety and effectiveness profile of the predicate MR systems, as determined by their prior FDA clearances (K945827 and K964626). The applicant demonstrates that their new device either matches or improves upon these predicate specifications without raising new questions of safety or effectiveness.
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The sample size for the training set:
- Not applicable. There is no AI model or algorithm being "trained" with data in this submission. This is a hardware and software upgrade.
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How the ground truth for the training set was established:
- Not applicable. As no training set exists, no ground truth needed to be established for it.
§ 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.