(70 days)
The Signa Contour 2 System is indicated for use as a diagnostic imaging device to produce transverse, sagittal, coronal and oblique images of the internal structures of the head or body. The images produced 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 determining a diagnosis.
The Signa Contour 2 System utilizes a superconducting magnet to acquire 2D single-slice and multi-slice, and 3D volume images. A wide variety of pulse sequences is provided to the operator, including inversion recovery, spin echo, gradient recalled, and steady state, free precession acquisitions. Imaging options such as cardiac gating, peripheral gating, flow compensation and fathwater suppression are provided to suppress artifacts due to physiological motion and improve image quality. The system can be used as a stationary or mobile system.
The provided text is for a 510(k) premarket notification for a medical device, the "Signa Contour 2 Magnetic Resonance System." This type of submission is for demonstrating substantial equivalence to a predicate device, not for proving clinical efficacy or diagnostic performance in the same way a new drug or a novel AI-driven diagnostic device would.
Therefore, the document does not contain the detailed information required to answer your questions regarding acceptance criteria, device performance, ground truth, expert involvement, or sample sizes for clinical studies. The summary focuses on comparing the new device's technical specifications and safety standards to a previously cleared product.
Here's why each of your requested points cannot be addressed with the provided text:
- A table of acceptance criteria and the reported device performance: The document states the device "was evaluated to the appropriate NEMA performance standards as well as the IEC 601-1 International medical equipment safety standard." However, it does not list specific imaging performance metrics (e.g., resolution, signal-to-noise ratio, diagnostic accuracy for specific conditions) as acceptance criteria or report actual performance values against those criteria.
- Sample size used for the test set and the data provenance: There is no mention of a "test set" in the context of diagnostic performance or clinical outcomes. The evaluation was primarily against technical and safety standards.
- Number of experts used to establish the ground truth for the test set and the qualifications of those experts: As no clinical "test set" for diagnostic performance is described, there's no mention of experts establishing ground truth for such a set. The device is for image acquisition, and interpretation is done by a "trained physician," but this is a general statement about usage, not a study design detail.
- Adjudication method (e.g., 2+1, 3+1, none) for the test set: Not applicable, as no clinical test set for diagnostic performance is described.
- 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 an MRI scanner, not an AI-driven image analysis tool. There's no mention of AI or assistance to human readers.
- If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This is an MRI scanner, not an algorithm.
- The type of ground truth used (expert consensus, pathology, outcomes data, etc.): Not applicable. The device's evaluation was against technical and safety standards, not clinical diagnostic accuracy with a "ground truth."
- The sample size for the training set: Not applicable. There is no mention of a training set as this is not an AI algorithm being validated.
- How the ground truth for the training set was established: Not applicable.
In summary, the provided document from a 1997 510(k) submission for an MRI scanner focuses on demonstrating technical and safety equivalence to a predicate device. It does not contain the type of clinical study design and performance data typically associated with the evaluation of diagnostic efficacy or AI-driven medical devices.
§ 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.