(172 days)
Vantage Galan 3T systems are indicated for use as a diagnostic imaging modality that produces crosssectional transaxial, coronal, sagittal, and oblique images that display anatomic structures of the head or body. Additionally, this system is capable of non-contrast enhanced imaging, such as MRA.
MRI (magnetic resonance imaging) images correspond to the spatial distribution of protons (hydrogen nuclei) that exhibit nuclear magnetic resonance (NMR). The NMR properties of body tissues and fluids are:
- Proton density (PD) (also called hydrogen density)
- Spin-lattice relaxation time (T1)
- Spin-spin relaxation time (T2)
- Flow dynamics
- Chemical Shift
Depending on the region of interest, contrast agents may be used. When interpreted by a trained physician, these images yield information that can be useful in diagnosis.
The Vantage Galan (Model MRT-3020) is a 3 Tesla Magnetic Resonance Imaging (MRI) System, previously cleared under K181593. This system is based upon the technology and materials of previously marketed Canon Medical Systems and is intended to acquire and display crosssectional transaxial, coronal, sagittal, and oblique images of anatomic structures of the head or body.
The provided text is a 510(k) summary for the Canon Medical Systems Corporation's Vantage Galan 3T, MRT-3020, V6.0 MRI System. This document focuses on demonstrating substantial equivalence to a predicate device, rather than providing a detailed study report with specific acceptance criteria and performance metrics for a novel AI device.
Therefore, the requested information elements (1, 2, 3, 4, 5, 7, 8, 9) regarding acceptance criteria, sample sizes, expert qualifications, ground truth establishment, and MRMC effectiveness studies cannot be fully extracted from this document as it is not a study report for an AI device.
However, based on the information provided regarding the "Compressed SPEEDER" feature, which is a new software functionality, I can deduce some aspects related to its evaluation.
Here's a breakdown of what can be extracted or inferred, and what cannot:
1. A table of acceptance criteria and the reported device performance
| Acceptance Criteria (Inferred from testing) | Reported Device Performance (Inferred from conclusion) |
|---|---|
| SNR (related to image quality) | Compressed SPEEDER met all acceptance criteria. |
| Unfolding error artifacts (related to image quality) | Compressed SPEEDER met all acceptance criteria. |
| Performance in all phase encode directions (related to image quality) | Compressed SPEEDER met all acceptance criteria. |
| Diagnostic quality of images (clinical utility) | Images were of diagnostic quality. |
| Image degradation assessment (clinical utility) | Positive assessment, indicating no significant degradation. |
| Lesion conspicuity (clinical utility) | Positive assessment, indicating maintained or improved conspicuity. |
| Clinical utility (overall usefulness) | Positive assessment, indicating clinical utility. |
2. Sample size used for the test set and the data provenance
- Sample Size:
- For technical image quality metrics (SNR, unfolding error, phase encode performance): Phantoms and volunteer images were used. The exact number of phantoms or volunteers is not specified.
- For clinical image quality assessment by radiologists: Representative images were obtained using the subject device. The exact number of images or cases is not specified.
- Data Provenance: Not explicitly stated, but given it's a medical device submission by a Japanese company with a U.S. agent, the volunteer imaging likely occurred either in Japan or the US. This was a prospective evaluation of the new software feature.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Number of experts: Not explicitly stated, but referred to as "American Board Certified Radiologists" (plural), indicating at least two.
- Qualifications of experts: "American Board Certified Radiologists." No specific experience level (e.g., "10 years of experience") is provided.
4. Adjudication method for the test set
- The document states that reviewers (radiologists) "provided detailed assessments." It does not specify an adjudication method (e.g., 2+1, 3+1, none) for reaching a consensus on the diagnostic quality or other assessments if multiple radiologists were involved. It simply says "reviewed by American Board Certified Radiologists."
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, an MRMC comparative effectiveness study was not explicitly mentioned or performed in the context of human reader improvement with AI assistance. The evaluation focused on the diagnostic quality of images produced by the device's new "Compressed SPEEDER" and "T2 Map" features, reviewed by radiologists, rather than comparing human reader performance with and without AI assistance from these features. The device's features (Compressed SPEEDER) are about image acceleration and quality, not necessarily AI for diagnostic assistance to humans.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Yes, a standalone evaluation of the "Compressed SPEEDER" algorithm's technical performance was done using phantoms and volunteer images to assess SNR, unfolding error artifacts, and performance in all phase encode directions. The algorithm's output (images) was then assessed for diagnostic quality by radiologists. This refers to the algorithm generating the images, which are then interpreted.
7. The type of ground truth used
- For the technical image quality metrics (SNR, unfolding error, phase encode performance), the ground truth was based on known phantom dimensions and electromagnetic properties, along with expected image characteristics from volunteer scans.
- For the clinical assessment by radiologists, the ground truth was expert consensus (implied, as radiologists reviewed and confirmed diagnostic quality). No mention of pathology or outcomes data as ground truth is made.
8. The sample size for the training set
- The document does not specify a training set size or methodology. It is a 510(k) summary for a software update to an MRI system, not a detailed algorithm development report. It is likely that the Compressed SPEEDER algorithm was developed and trained internally by Canon Medical Systems, but details are not provided here.
9. How the ground truth for the training set was established
- As the training set itself is not mentioned, the method for establishing its ground truth is not provided in this document.
§ 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.