(82 days)
To be used in conjunction with a Magnetic Resonance Scanner to produce diagnostic images of Carotid structures that can be interpreted by a trained physician. The Machnet Carotids Coil is designed to provide coverage of the carotid arteries and associated vasculature from the aortic arch through the Circle-of-Willis. Anatomic Regions: Head and Neck Vasculature. Nuclei Excited: Hydrogen The indications for use are the same as for standard imaging: The GE Signa system is indicated for use as an NMR device that produces images that: (1) correspond to the distribution of protons exhibiting NMR signal, (2) depend upon the density, spin lattice relaxation time Tl, spin-spin relaxation time T2) and (3) and (2) tissue. When interpreted by a trained physician, these images of the head and neck regions specifically the carotid arteries and association can be useful in the determination of a diagnosis.
The Carotids Coil Array Assembly is a receive only coil array which consists of a dual set of coils electrically connected to a quick disconnect box which interfaces the assembly to the MR scanner. Each half of the coil assembly consists of two overlapping coils to buck out the mutual inductance between the coils. Active decoupling is achieved by PIN diodes which turn the coils to a high impedance state at transmit time. A pair of fast switching crossed diodes is installed in each coil segment acting as passive switches detuning the coils to further improve the safety of the Carotids Coil Array Assembly. Each transmission line has so called "bazooka baluns" installed to minimize the outer braiding currents on the coaxial cables. Coil diameter have been chosen to optimize sensitivity at distances to about 35 mm from the coil surface while a sharp cutoff beyond 40 mm from the surface minimizes the noise from volumes outside the region of interest. This ensures maximum signal ratio from the region of the carotids arteries.
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Safe and effective operation | Testing performed according to internal company procedures. Test results support the conclusion that actual device performance satisfies the design intent. The device is substantially equivalent to the predicate device. |
| Compatible with MRI scanners | Compatible with SignaTM (1.5Tesla) MRI scanner manufactured by GE Medical Systems, Inc., specifically Signa Advantage 1.5T and 1.0T, and Signa Horizon LX 1.5T and 1.0T. |
| Provides diagnostic images of carotid structures | The device produces diagnostic images of carotid structures that can be interpreted by a trained physician, covering carotid arteries and associated vasculature from the aortic arch through the Circle-of-Willis. |
| Minimizes noise from outside region of interest | Coil diameter chosen to optimize sensitivity at distances to about 35 mm from the coil surface while a sharp cutoff beyond 40 mm from the surface minimizes the noise from volumes outside the region of interest. This ensures maximum signal ratio from the region of the carotid arteries. |
2. Sample size used for the test set and the data provenance:
The provided document (K012491 510(k) Summary) does not explicitly detail the sample size or provenance of data used for testing. It generally states that "Testing was performed according to internal company procedures" and that "Test results support the conclusion that actual device performance satisfies the design intent." This suggests that the testing was likely conducted in-house by Machnet BV. Given the submission date of 2001, it is highly probable that the testing, if it involved patient data, was retrospective, but this is not explicitly stated.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
This information is not provided in the document. The document mentions that images "can be interpreted by a trained physician," implying the eventual use by medical professionals, but it does not describe who established the ground truth for validating the device's performance during testing.
4. Adjudication method for the test set:
This information is not provided in the document.
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:
No. This document describes a medical device (a coil array for MRI) and its substantial equivalence to a predicate device, not an AI or algorithm-driven diagnostic tool. Therefore, an MRMC study comparing human readers with and without AI assistance is not applicable and was not performed.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
No. This document concerns a physical medical device (an MRI coil), not a standalone algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
The document does not explicitly state the type of ground truth used for testing. Given the nature of an MRI coil, "ground truth" would likely relate to image quality parameters such as signal-to-noise ratio, spatial resolution, and artifact levels, assessed against established benchmarks or comparative images from the predicate device. However, specifics are not provided beyond "Test results support the conclusion that actual device performance satisfies the design intent."
8. The sample size for the training set:
Not applicable. As this is a physical medical device (an MRI coil) and not an AI or machine learning algorithm, there is no "training set."
9. How the ground truth for the training set was established:
Not applicable, as there is no training set for this type of device.
§ 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.