(48 days)
The intended use of the Performance package is to enable the permanent magnet based MRI systems designed by Paramed (MrJ and MrJ Inspire) to perform MR scan of the following districts: C-Spine one dedicated coil (code 01-2023), L-Spine two sizes of dedicated coils (codes 01-2021 and 01-2022), all other joints using a linear single channel coil named MP wrap (code 01-2024) which is not aimed to specific districts but can fit most joints (such as, for instance, knee, foot, ankle, elbow, wrist, hand ... ). The Performance package inherits the same limitations of the System to which it is applied which is: only joint pathologies ( no tumor, no angiography). The Performance package enables the MRI System to which it is applied to acquire images of the districts being diagnosed in transverse, sagittal, coronal and oblique cross-sectional directions. The images which are produced correspond to spatial distribution of protons (hydrogen nuclei) that check the magnetic resonance properties and depend upon MR parameters (spin-lattice relaxation time (T1), spin-spin relaxation time (T2), nuclei density, flow velocity and chemical shift). If interpreted by a medical expert, these images can provide diagnostically useful information.
The Performance Package for MrJ series (MrJ and MRJ Inpsire) permanent magnet based MRI tomographs is a set of receiving coils intended to increase patient comfort while performing the same district examinations already performed by previously marketed receiving coils. The two here proposed Kits differ only for what regards the connector to the magnet which for MrJ is flat and for MrJ Inspire it is round. The components of the Performance Package (for MrJ and MRJ Inpsire) are the following: C-Spine dedicated coil, L-Spine dedicated coils (Small size and Large size), MP_wrap multipurpose coil. The Proposed coils are receive coils. The images produced by the device, when Performance Package is employed reflect the spatial distribution of protons (hydrogen nuclei) exhibiting magnetic resonance. The MR parameters that determine image appearance are proton density, spin-lattice relaxation time (T1), spin-spin relaxation time (T2), chemical shift and flow velocity. When interpreted by a trained physician, these images can yield information that can be useful in the determination of a diagnosis.
Acceptance Criteria and Device Performance Study for Paramed Performance Package
This document describes the acceptance criteria and the study conducted to demonstrate that the Paramed Performance Package accessory for MRI systems meets these criteria.
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for the device are focused on the Signal-to-Noise (S/N) ratio, measured according to NEMA procedures.
| Item (Coil Model) | Acceptance Criteria (S/N values acceptable, NEMA procedures) | Reported Device Performance (Signal/Noise as measured through NEMA Standard) | S/N Accepted at Final Inspection (procedure limits)* |
|---|---|---|---|
| 01-2021-00 (L-Spine Small) | ≥ 16.5 | 18.68 | 31 |
| 01-2021-01 (L-Spine Small) | (No value reported, assumed similar to 01-2021-00) | (No value reported, assumed similar to 01-2021-00) | (No value reported, assumed similar to 01-2021-00) |
| 01-2022-00 (L-Spine Large) | ≥ 13.5 | 15.43 | 26 |
| 01-2022-01 (L-Spine Large) | (No value reported, assumed similar to 01-2022-00) | (No value reported, assumed similar to 01-2022-00) | (No value reported, assumed similar to 01-2022-00) |
| 01-2023-00 (C-Spine) | ≥ 17 | 18.14 | 40 |
| 01-2023-01 (C-Spine) | (No value reported, assumed similar to 01-2023-00) | (No value reported, assumed similar to 01-2023-00) | (No value reported, assumed similar to 01-2023-00) |
| 01-2024-00 (MP-Wrap) | ≥ 21 | 22.15 | 50 |
| 01-2024-01 (MP-Wrap) | (No value reported, assumed similar to 01-2024-00) | (No value reported, assumed similar to 01-2024-00) | (No value reported, assumed similar to 01-2024-00) |
*Note: The values accepted at final inspection are derived from those obtained according to NEMA procedure with scaling factors applied to take into account different sequence and FOV. The reported device performance (Signal/Noise as measured through NEMA Standard) meets or exceeds the specified acceptance criteria for all listed coils.
2. Sample Size Used for the Test Set and Data Provenance
The document indicates "test images performed both on phantoms and on healthy volunteers." However, specific sample sizes for the test set (number of phantoms and healthy volunteers) are not provided in the submitted summary.
The provenance of the data is implied to be from internal laboratory testing conducted by Paramed S.r.l. in Genova, Italy. The testing included both phantom studies and studies with healthy volunteers, suggesting a prospective data collection approach for at least the volunteer component.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document states that if images are "interpreted by a medical expert, these images can provide diagnostically useful information." However, the number of experts used to establish the ground truth for the test set and their specific qualifications are not explicitly stated within the provided text. The phrase "medical expert" is general and does not provide specific details on their background (e.g., radiologists, years of experience, subspecialty).
4. Adjudication Method for the Test Set
The document does not describe any specific adjudication method (e.g., 2+1, 3+1, none) for establishing ground truth from multiple experts. Given that the study primarily focuses on technical performance like SNR and general image quality assessment, formal expert adjudication of diagnostic outcomes may not have been deemed necessary or explicitly documented for this type of submission.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No Multi-Reader Multi-Case (MRMC) comparative effectiveness study is mentioned in the provided special 510(k) summary. The document does not discuss the effect size of how much human readers improve with AI vs. without AI assistance, as AI assistance is not the subject of this submission. The device is a set of receiving coils, an accessory for MRI systems, not an AI-powered diagnostic tool.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
No standalone (algorithm only) performance study was conducted or is applicable to this device. The Performance Package consists of MRI receiving coils, which are hardware accessories, not algorithms or software that operate independently without human interaction.
7. Type of Ground Truth Used
The ground truth for the device's performance was established through:
- Phantom studies: These evaluate objective technical parameters like Signal-to-Noise Ratio (SNR) under controlled conditions.
- Healthy volunteer images: These allow for the assessment of image quality in human subjects, likely evaluated subjectively by experts or internally against established standards for clear anatomical visualization.
The document emphasizes that clinical output is "documented at section Validation activities" and that "no clinical study is necessary" because the components are "well known in the clinical practice." This implies that the 'ground truth' for image diagnostic utility relies on the well-established principles of MRI and the visual interpretability of the acquired images rather than specific disease outcomes or pathology.
8. Sample Size for the Training Set
No sample size for a training set is provided. The device is a physical accessory (MRI coils), not a machine learning or AI algorithm that requires a training set.
9. How the Ground Truth for the Training Set Was Established
This question is not applicable as there is no training set for this 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.