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The 31P/1H headcoil for MAGNETOM Allegra is a transmit/receive birdcage type headcoil double resonant on phosphorus (31P) and proton (1H) frequencies.

Used in the Allegra system it is indicated for use as a diagnostic imaging device to produce 1H images and 1H spectra of the internal structures of the head. In addition, 31P spectra can be obtained within the same session without changing the coil.

The images produced reflect the spatial distribution of protons exhibiting magnetic resonance. Spectra allow the molecules, in which the nucleus under investigation is contained, to be distinguished. The NMR properties that determine the image and spectra appearance are spin density, spin-lattice relaxation time (T1), spin-spin echo time (T2) and resonance frequency of the corresponding nucleus.

When interpreted by a trained physician, these images and spectra provide information that can be useful in determining diagnosis.

The 31P/1H headcoil for MAGNETOM Allegra is a transmit/receive birdcage type quadrature headcoil double resonant on phosphorus (31P) and proton (1H) frequencies. It is optimized for the main application: 31P spectroscopy potentially including also proton decoupling.

The coil consists of the resonator and an electronic box, which serves for switching transmit/receive, quadrature splitting, preamplifying and lowpass filtering in the receive pathway. The latter being essential for proton decoupling.

The provided text describes a 510(k) submission for a medical device, a 31P/1H headcoil for a MAGNETOM Allegra MRI system. This document focuses on establishing substantial equivalence to previously cleared devices rather than presenting a study with specific acceptance criteria and detailed performance metrics as one might find for a novel diagnostic algorithm.

Therefore, much of the requested information regarding "acceptance criteria" and "device performance" in the context of a study analyzing diagnostic accuracy (e.g., sensitivity, specificity, AUC) is not explicitly detailed in the provided content. The clearance for this device is based on its similarity to existing, cleared devices for performing MR imaging and spectroscopy.

Here's an analysis based on the available information:

1. Table of Acceptance Criteria and Reported Device Performance

Formal, quantifiable acceptance criteria in the sense of diagnostic performance metrics (e.g., specific sensitivity or specificity thresholds) are not provided in this 510(k) summary. The "acceptance" here is the FDA's determination of substantial equivalence to predicate devices. The performance is implicitly accepted as being similar to that of the predicate devices.

2. Sample Size Used for the Test Set and Data Provenance

This document does not describe a clinical study with a "test set" in the context of evaluating a diagnostic algorithm's performance on a specific dataset. The evaluation is based on technical specifications and comparison to predicate devices, not on a dataset of patient scans used for performance metrics.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

Not applicable. As there is no "test set" for diagnostic performance evaluation of an algorithm, there are no experts establishing ground truth for such a set described in this document.

4. Adjudication Method for the Test Set

Not applicable. There is no test set or adjudication method described.

5. 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 device is a hardware component (MRI coil), not an AI algorithm. Therefore, an MRMC study comparing human readers with and without AI assistance is irrelevant to this submission.

6. If a Standalone (i.e. algorithm only, without human-in-the-loop performance) was done

Not applicable. This is a hardware component, not a standalone AI algorithm.

7. The Type of Ground Truth Used

Not applicable in the typical sense of a diagnostic algorithm validation. The "ground truth" for this device's functionality would be its ability to produce technically sound 1H images and 31P spectra that are consistent with known physics and expected in vivo results, as assessed through engineering tests and comparison to established predicate devices.

8. The Sample Size for the Training Set

Not applicable. This is a hardware component, not an AI algorithm requiring a training set.

9. How the Ground Truth for the Training Set was Established

Not applicable. As above, this is a hardware device.

Summary of the Study that Proves the Device Meets Acceptance Criteria:

The "study" in this context is the 510(k) premarket notification process for substantial equivalence. Instead of a clinical trial demonstrating specific performance metrics against a "ground truth," the manufacturer, Bruker BioSpin MRI GmbH (and initial importer Siemens Medical Systems, Inc.), demonstrated that the 31P/1H headcoil for MAGNETOM Allegra is substantially equivalent to three previously cleared predicate devices:

• Siemens Medical Solutions 31P/1H heart/liver coil for Clinical Phosphorus Spectroscopy Option MAGNETOM Vision (K962627, cleared March 04, 1997)
• Siemens Medical Solutions 31P/1H heart/liver coil included in syngo MR 2002B (K020991, cleared June 13, 2002)
• GE Medical Systems Signa 1.5T Phosphorus Transmit/Receive Flex Coil (K983139, cleared February 19, 1999)

The basis of this equivalence is that the new device shares the same intended use (diagnostic imaging of the head for 1H images and spectra, and 31P spectra) and similar technological characteristics (transmit/receive birdcage type headcoil, double resonant on 31P and 1H frequencies) as the predicate devices. The submission likely included technical specifications, engineering test results, and a comparison of performance characteristics (e.g., coil geometry, resonant frequencies, image quality metrics) to demonstrate that the new coil performs similarly to the predicate devices and raises no new questions of safety or effectiveness. The FDA's review and clearance (K042617) signify their agreement with this claim of substantial equivalence.

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