(322 days)
The Discovery MR750w 3.0T is a whole body magnetic resonance scanner designed to support high resolution, high signal-to-noise ratio, and short scan times. It is indicated for use as a diagnostic imaging device to produce axial, sagittal, coronal, and oblique images, spectroscopic images, parametric maps, and/or spectra, dynamic images of the structures and/or functions of the entire body, including, but not limited to, head, neck, TMJ, spine, breast, heart, abdomen, pelvis, joints, prostate, blood vessels, and musculoskeletal regions of the body. Depending on the region of interest being imaged, contrast agents may be used. The images produced by the Discovery MR750w 3.0T reflect the spatial distribution or molecular environment of nuclei exhibiting magnetic resonance. These images and/or spectra when interpreted by a trained physician yield information that may assist in diagnosis.
The Discovery MR750w 3.0T features a superconducting magnet operating at 3.0 Tesla. The data acquisition system accommodates up to 32 independent receive channels in various increments, and multiple independent coil elements per channel during a single acquisition series. The system uses a combination of time-varying magnetic fields (gradients) and RF transmissions to obtain information regarding the density and position of elements exhibiting magnetic resonance. The RF technology of the Discovery MR750w system integrates an RF transmit architecture designed to improve the overall image uniformity. This technology, called Multi-drive, optimizes RF transmit by adjusting the amplitude and phase of the RF output depending on the anatomy being scanned. In order to support Multi-Drive, the RF Transmit (Tx) chain is changed from MR750 and both Tx lines are divided into 2 lines with Dual output Exciter, Dual output RF amp, Dual Transmit/Receive Switch (DTRSW), dual UPM and a 70cm-wide patient bore RF body coil. The system can image in the sagittal, coronal, axial, oblique and double oblique planes, using various pulse sequences and reconstruction algorithms. The Discovery MR750w 3.0T is designed to conform to NEMA DICOM standards (Digital Imaging and Communications in Medicine).
Here's a breakdown of the requested information based on the provided 510(k) summary for the Discovery MR750w 3.0T.
1. Table of Acceptance Criteria and Reported Device Performance
The 510(k) summary for the Discovery MR750w 3.0T primarily focuses on demonstrating substantial equivalence to predicate devices and adherence to established standards for safety and performance testing for Magnetic Resonance Imaging (MRI) systems. It does not provide specific numerical acceptance criteria with corresponding reported performance values in a direct table format. Instead, it states that various parameters "have been measured and documented through testing to NEMA, IEC or ISO standards" and that these tests were "executed with acceptable results."
Performance Parameters Tested:
| Acceptance Criteria (Implied by NEMA, IEC, ISO Standards) | Reported Device Performance (Stated as "Acceptable Results") |
|---|---|
| Signal-to-noise ratio (SNR) | Met standards |
| Geometric distortion | Met standards |
| Image uniformity | Met standards |
| Slice thickness | Met standards |
| Spatial resolution | Met standards |
Safety Parameters Tested:
| Acceptance Criteria (Implied by NEMA, IEC, ISO Standards) | Reported Device Performance (Stated as "Acceptable Results") |
|---|---|
| Static field strength | Met standards |
| Acoustic noise | Met standards |
| dB/dt | Met standards |
| RF heating (SAR) | Met standards |
| Biocompatibility | Met standards |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state a specific sample size for a "test set" in the context of clinical studies where individual cases are evaluated for device performance against a ground truth. Instead, it refers to "clinical images and clinical results summary" used to demonstrate imaging performance.
- Sample Size: Not explicitly stated. The summary refers to "clinical images and clinical results summary" but does not quantify the number of patients or images.
- Data Provenance: The manufacturing entity is GE Healthcare, (GE Healthcare Japan Corporation) and the contact person is in Japan. However, the document does not specify the country of origin of the clinical data (e.g., patient demographics, where the scans were acquired). It does not explicitly state whether the data was retrospective or prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not detail the process of establishing ground truth for a clinical test set in the way one might expect for an AI/CAD device. It states, "These images and/or spectra when interpreted by a trained physician yield information that may assist in diagnosis." This implies that the interpretation by trained physicians (plural) constitutes the clinical reference standard or ground truth.
- Number of Experts: The document does not specify the number of experts. It generally refers to interpretation by "a trained physician" (singular in the Indications for Use, but "physicians" is implied for general clinical practice).
- Qualifications of Experts: The document only states "trained physician." No specific qualifications (e.g., specialty, years of experience) are provided.
4. Adjudication Method for the Test Set
The document does not describe any specific adjudication method (e.g., 2+1, 3+1, none) for a test set. This type of detail is typically found in studies for AI-powered diagnostic devices, where disagreements among readers about ground truth or device performance are resolved. For this MRI system, the primary focus is on technical performance and equivalence to predicates, rather than a diagnostic performance study with specific adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not explicitly described or reported in this 510(k) summary. The document does not discuss human reader performance, with or without AI assistance. The summary's focus is on the device's technical performance and safety, and its substantial equivalence to predicate MRI systems.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
The Discovery MR750w 3.0T is a Magnetic Resonance Imaging System, not an algorithm or AI-powered diagnostic tool in the typical sense that would have "standalone performance" evaluated for diagnostic accuracy. It's a hardware system that generates images. Therefore, the concept of "standalone performance" as it applies to an algorithm without human-in-the-loop is not relevant here. The device's performance is inherently tied to the quality of the images it produces, which are then interpreted by a human physician.
7. The Type of Ground Truth Used
The ground truth for clinical evaluation is implicitly based on expert consensus/interpretation by trained physicians using the images produced by the device. The document states that "images and/or spectra when interpreted by a trained physician yield information that may assist in diagnosis." This suggests the clinical utility is assessed through conventional medical diagnostic workflows. There is no mention of pathology, long-term outcomes data, or other objective ground truth methods.
8. The Sample Size for the Training Set
The concept of a "training set" is not applicable in the context of this 510(k) submission. The Discovery MR750w 3.0T is an MRI system, a hardware device, not a machine learning or AI algorithm that requires a training set of data. Its design and performance are based on engineering principles, physics, and established medical imaging standards, rather than learned patterns from a dataset.
9. How the Ground Truth for the Training Set Was Established
Since the device is an MRI system and not an AI algorithm, there is no "training set" or corresponding ground truth establishment process in the machine learning sense. The device's operational parameters and image quality are validated against physical phantoms, engineering specifications, and established industry standards (NEMA, IEC, ISO).
§ 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.