(34 days)
S-scan is a Magnetic Resonance (MR) system that produces transversal, sagittal and coronal and oblique cross-section images of the limbs, joints and spinal column. It is intended for imaging portions of the upper limb, including the hand, wrist, forearm, elbow, arm and shoulder, imaging portions of the lower limb, including the foot, ankle, calf. knee. thigh and hip, imaging of the temporomandibular joint and imaging the cervical spine and the lumbar spine sections as portions of the spinal column.
S-scan images correspond to the spatial distribution of protons (hydrogen nuclei) that determine magnetic resonance properties and are dependent on the MR parameters, including spin-lattice relaxation time (T1), spin-spin relaxation time (T2), nuclei density, flow velocity and "chemical shift". When interpreted by a medical expert trained in the use of MR equipment, the images can provide diagnostically useful information.
The changes performed on the modified S-scan device, with respect to the cleared version – S-scan K110802 - are due to the improvement of the system performance. These modifications, which do not affect the intended use or alter the fundamental scientific technology of the device, are the following:
- A new step for patient positioning.
- A kit for patient positioning during hip examination using 4-channels lumbar spine coil 17 and 18.
- Geometric distortion correction.
- FSE parameters optimization
- FSE acceleration and improving.
- FSE sampling frequency management.
- Streaming acquisition performance increasing.
- Configurable send and export of XBONE echoes.
- Environment for the management of the virtual film.
- Data matching for patient coming from a worklist server.
- SpeedUp technique introduction, cleared via K120748.
- A new software version.
This 510(k) submission (K121650) for the S-Scan MR system describes modifications to an already cleared device (K110802), rather than a new device that requires extensive clinical validation to demonstrate its performance against acceptance criteria. Therefore, the information typically associated with acceptance criteria and a detailed study proving performance (e.g., specific metrics, ground truth establishment, sample sizes for training/testing datasets, expert qualifications, adjudication methods, or MRMC studies) is not explicitly provided in the document.
The submission focuses on demonstrating that the modifications to the S-Scan device do not affect its intended use or alter its fundamental scientific technology, and thus the device remains substantially equivalent to its predicate. The "acceptance criteria" here are implied to be that the improved system performance from the modifications does not negatively impact image quality or diagnostic utility against the baseline established by the predicate device.
However, based on the provided text, we can infer some aspects related to the device performance implicitly.
Here's an analysis based on the document, addressing as many of your points as possible:
1. A table of acceptance criteria and the reported device performance
Since this is a Special 510(k) for device modifications, explicit "acceptance criteria" for a new device's performance are not detailed in the provided text. The implicit acceptance criterion is that the modified device's performance is at least equivalent to, or improved compared to, the predicate device (K110802), specifically in areas where modifications were made, without compromising the overall diagnostic utility.
| Acceptance Criterion (Implicit) | Reported Device Performance (Implicit from modifications) |
|---|---|
| No degradation of image quality | |
| for diagnostic interpretation. | System performance improvements via: |
- Geometric distortion correction.
- FSE parameters optimization.
- FSE acceleration and improving.
- FSE sampling frequency management.
- Streaming acquisition performance increasing.
- SpeedUp technique introduction.
These modifications aim to enhance image quality and acquisition efficiency. |
| Maintenance of intended use and
fundamental scientific technology. | Stated: "These modifications, which do not affect the intended use or alter the fundamental scientific technology of the device."
The images "can provide diagnostically useful information" when interpreted by a medical expert. |
| Compliance with general controls
and relevant regulations. | Reviewed by FDA for substantial equivalence and allowed to market. |
2. Sample size used for the test set and the data provenance
The document does not specify a separate "test set" sample size or data provenance for a performance study. Since the modifications are for an already cleared device, it's likely that internal verification and validation activities were performed by the manufacturer, rather than a new clinical study with a distinct test set described in the 510(k). No information is provided regarding the country of origin or whether data was retrospective or prospective.
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. Given the nature of a Special 510(k) for modifications to an established MR system, it's improbable that a new, extensive ground truth establishment process for a clinical test set was required and detailed in this submission. The "ground truth" for the diagnostic utility of MR images, in general, is implicitly established by the experience and training of "a medical expert trained in the use of MR equipment."
4. Adjudication method for the test set
Not specified 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
An MRMC study is not mentioned. The device described is an MR system, not an AI-assisted diagnostic tool, so the concept of "human readers improve with AI vs without AI assistance" does not apply to this submission.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. The S-Scan is an MR imaging system, not a standalone algorithm. Its output, images, requires interpretation by a human expert.
7. The type of ground truth used
The ground truth is implied to be expert interpretation of MR images. The document states: "When interpreted by a medical expert trained in the use of MR equipment, the images can provide diagnostically useful information." There is no mention of pathology or outcomes data as direct ground truth for this submission, as the submission focuses on system modifications.
8. The sample size for the training set
Not applicable. This document describes modifications to an MR imaging system. It is not an AI/algorithm-based device that would typically have a "training set" in the context of machine learning.
9. How the ground truth for the training set was established
Not applicable, as there is no mention of a training set for an AI/algorithm.
§ 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.