(34 days)
The Wrist 3 MRI System is intended for use as a magnetic resonance imaging device for producing axial, sagittal, coronal, and oblique images of the internal structure of the Wrist and Hand. When interpreted by a trained physician, these images provide information that can be useful in determining a diagnosis.
The Wrist 3 MRI System is a 1Tesla Permanent MRI system producing MR images of the wrists and hands. During MRI scan, body parts to be imaged are held within a uniform static magnetic field, and are subject to sequences of RF pulses and gradient magnetic fields. The signal from the precession of the magnetization created by these fields is sampled and processed to produce image data.
The provided document is a 510(k) premarket notification for the Aspect Imaging Wrist 3 MRI System. It primarily focuses on demonstrating substantial equivalence to a predicate device (M2 Wrist 2 MRI System K130692) rather than presenting a detailed study with specific acceptance criteria and performance metrics for a novel diagnostic algorithm.
Therefore, much of the requested information cannot be extracted directly from this document. However, I can provide the available information:
1. Table of Acceptance Criteria and the Reported Device Performance:
The document does not explicitly state quantitative acceptance criteria or detailed performance metrics for the Wrist 3 MRI System in terms of diagnostic accuracy, sensitivity, specificity, or other outcome-based measures. The evaluation is based on demonstrating compliance with voluntary consensus standards and comparing technical specifications to the predicate device.
| Acceptance Criteria (Inferred from regulatory context) | Reported Device Performance (Summary of Technical Comparison) |
|---|---|
| Compliance with Safety and Performance Standards | Tested to comply with IEC/ES 60601-1, IEC 60601-1-2, IEC 60601-2-33, NEMA MS-1, NEMA MS-3, NEMA MS-2, NEMA MS-12, NEMA MS-5. System and Software verification and Validation testing performed. |
| Image Production Capability | Intended for producing axial, sagittal, coronal, and oblique images of the internal structure of the Wrist and Hand. This is an expansion of the predicate device's capability which listed only transverse, sagittal and coronal images of the wrist. |
| Diagnostic Utility | Images, when interpreted by a trained physician, provide information useful in determining a diagnosis. (This is a statement of intended use rather than quantitatively measured performance). |
| Substantial Equivalence to Predicate | Technology: Employs the same fundamental scientific technology (1 Tesla Permanent MRI system) as the predicate (M2 Wrist 2 MRI System K130692). |
| Intended Use/Indication for Use: Expanded to include "Hand" and "oblique" images in addition to "Wrist," "axial, sagittal, coronal." | |
| Patient Population: Expanded to "Wrist and Hand." | |
| Anatomical Sites: Expanded to "Wrist and Hand." | |
| Environment of Use: Hospital or clinical setting (same). | |
| Energy Used: Magnetic Resonance (same). | |
| Human Factors: Designed similar to other commercially available MRI Systems, user-friendly software interface (same claim). | |
| Hardware Changes (Wrist 3 vs. M2 Wrist 2): |
- Magnet Physical Dimensions: 138x87x82 cm (vs. 125x87x82 cm)
- Bore opening: 85x220 mm (vs. 76x200 mm)
- Weight: 1300 Kg (1700 with Trolley) (vs. 1050 Kg)
- Field Strength: 1 Tesla Permanent Magnet (same).
- Gradient Strength: 215 mT/m (vs. 190 mT/m)
- Gradient Rise Time: 0.200mSec (vs. 0.475mSec)
- Gradient Slew Rate: 1074 T/m/Sec (vs. 400 T/m/Sec)
- Computer Display: 15" Touch Display (vs. 24" LCD Desktop Display)
- RF Coils: 2 Coils: Small/Large (vs. 1 Coil)
- Coil Type: TX/RX (same)
- Coil Geometry: Oval (same)
- Inner Dimensions (mm): 60X100X169 / 75X135X192 (vs. 50X108X86)
- Coil Design: Linear Volume (same). |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):
The document states, "The subject of this premarket submission, Wrist 3 MRI System, did not require clinical studies to support substantial equivalence." It mentions "Sample clinical images" were part of the design controls activity, but does not provide details on their sample size, provenance, or whether they constituted a formal "test set" for performance evaluation against ground truth.
3. 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, as no formal clinical study with a detailed test set and ground truth establishment is described. The "sample clinical images" used were likely for qualitative assessment as part of design validation, but the ground truth establishment method and expert details are not provided.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:
Not applicable, as no formal clinical test set or adjudication process is 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 an MRI system, not an AI-assisted diagnostic tool for image interpretation. Therefore, an MRMC comparative effectiveness study comparing human readers with and without AI assistance is not relevant to this submission.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
Not applicable. This is a medical imaging device, not an image analysis algorithm designed for standalone performance.
7. The type of ground truth used (expert concensus, pathology, outcomes data, etc):
Not applicable, as no formal clinical study with ground truth establishment is described.
8. The sample size for the training set:
Not applicable, as this is an MRI system, not an AI model that requires a training set in the conventional sense.
9. How the ground truth for the training set was established:
Not applicable, as this is an MRI system, not an AI model that requires a training set.
§ 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.