(17 days)
Pediatric Population: The InkSpace Imaging Body Array is a receive-only coil, used for obtaining diagnostic images of pediatric cardiac and body in GE 3.0T magnetic resonance imaging systems. These images, when interpreted by a trained physician, yield information that may assist in diagnosis. Adult Population: The InkSpace Imaging Body Array is a receive-only coil, used for obtaining diagnostic images of general human anatomy in adults, such as spine, shoulder, elbow, knee, foot, and prostate resonance imaging systems. These images, when interpreted by a trained physician, yield information that may assist in diagnosis.
The InkSpace Imaging Body Array is a phased array, receive-only coil intended to work with GE 3.0T MRI scanners to provide optimal signal-to-noise ratio and uniformity for high resolution body MR imaging examinations. The size and layout of individual channels of the InkSpace Imaging Body Array were designed to fit the pediatric and adult populations for body imaging. The coil is comprised of 24 total channels, with two individual flexible pads, intended to be placed anterior and posterior to the patient, containing 12 individual elements. The elements are optimized to be flexible to conform to pediatric and adult patients' anatomies.
The document provided is a 510(k) premarket notification for a medical device called the "InkSpace Imaging Body Array," which is a receive-only coil for Magnetic Resonance Imaging (MRI) systems. The document focuses on demonstrating substantial equivalence to a predicate device (InkSpace Imaging Pediatric Body Array, K213397) rather than establishing novel acceptance criteria for a new device's performance.
Therefore, the acceptance criteria and study detailed in this document are primarily concerned with demonstrating that the modified device (InkSpace Imaging Body Array) functions as safely and effectively as its predicate device (InkSpace Imaging Pediatric Body Array). The "acceptance criteria" here are implicitly related to the performance characteristics of an MRI coil, and the "study" is a set of non-clinical tests and an assessment of acquired image quality.
Here's a breakdown of the requested information based on the provided text:
1. A table of acceptance criteria and the reported device performance
The document does not explicitly present a table of acceptance criteria with corresponding performance metrics for the InkSpace Imaging Body Array as if it were a new device needing to meet predefined thresholds. Instead, it states that the device had to demonstrate substantial equivalence to the predicate. The "performance criteria" referenced in the guidance document are general for MR receive-only coils, and the testing was done to ensure the modified device meets established specifications and does not raise different questions of safety or effectiveness compared to the predicate.
The table below summarizes the characteristics that were assessed for "performance" in the context of substantial equivalence:
| Characteristic Assessed | Acceptance Criteria (Implicit from Substantial Equivalence Goal) | Reported Device Performance (Summary) |
|---|---|---|
| Image Signal to Noise (SNR) | Consistent with or comparable to the predicate device and established specifications for MR receive-only coils. | Nonclinical testing demonstrating the device meets established specificationsnecessary for consistent performance. |
| Image Uniformity | Consistent with or comparable to the predicate device and established specifications for MR receive-only coils. | Nonclinical testing demonstrating the device meets established specificationsnecessary for consistent performance. |
| Surface Heating | Within safe limits, comparable to the predicate device, and meeting established specifications. | Nonclinical testing demonstrating the device meets established specifications for consistent performance and does not raise different questions of safety. |
| Decoupling Circuit | Functioning correctly and safely, comparable to the predicate device. | Nonclinical testing demonstrating the device meets established specificationsfor consistent performance and does not raise different questions of safety. |
| EMC Immunity, Electrostatic Discharge | Meeting regulatory standards and comparable to the predicate device. | Nonclinical testing demonstrating the device meets established specificationsfor consistent performance and does not raise different questions of safety. |
| General Electrical/Mechanical Safety | Meeting relevant safety standards and comparable to the predicate device. | Nonclinical testing demonstrating the device meets established specifications for consistent performance and does not raise different questions of safety. |
| Acquired Image Quality (Adult Patients) | Images of clinical quality, providing information that may assist in diagnosis by a trained physician (similar to predicate's indication). | Sample clinical images from adult patients were reviewed, and their clinical quality was confirmed by a board-certified radiologist. The general conclusion is that the device is "safe, effective, and performs at least as safely and effectively as the legally marketed predicate device." |
| Biocompatibility Testing | Meeting ISO 10993 standards for cytotoxicity, sensitization, and irritation, similar to the predicate device. | Performed (referenced as having been done on the predicate and still applicable, and also implied for the modified device). |
| Usability Testing | Demonstrating safe and effective use, comparable to the predicate device. | Performed (referenced as having been done on the predicate). |
| Transit Testing | Ensuring integrity and functionality after transport, comparable to the predicate device. | Performed (referenced as having been done on the predicate). |
2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)
- Sample Size for Acquired Image Quality: Not explicitly stated as a number. The document refers to "sample clinical images from adult patients" and an "analysis of acquired image quality... based on sample clinical images from adult patients." This implies a qualitative assessment on a subset of images rather than a large-scale, quantitatively defined test set.
- Data Provenance: Not specified for the "sample clinical images from adult patients." It does not mention country of origin, nor whether the 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
- Number of Experts: "a board-certified radiologist." This indicates one expert.
- Qualifications of Experts: "board-certified radiologist." No specific experience level (e.g., "10 years of experience") is provided, but board certification implies a high level of qualification in the field.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
- Adjudication Method: Not applicable or "none" in the typical sense of multiple readers adjudicating cases. The review of clinical quality was performed by "a board-certified radiologist" (singular), suggesting a single-reader assessment for clinical quality.
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
- MRMC Study: No. The device is a receive-only MRI coil, not an AI-assisted diagnostic tool. Therefore, a multi-reader multi-case comparative effectiveness study comparing human readers with and without AI assistance is not relevant to this device and was not conducted. The study was to establish substantial equivalence for the coil itself.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Standalone Performance: No. This device is an MRI coil, which is a hardware component that produces images. It is not an algorithm, and thus, "standalone" algorithmic performance without human-in-the-loop is not applicable. The performance is assessed on the quality of the images it produces for human interpretation.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- Type of Ground Truth: For the "acquired image quality" assessment, the ground truth was the expert opinion/review of a board-certified radiologist regarding the clinical quality of the images. For the more objective non-clinical tests (SNR, uniformity, heating, etc.), the "ground truth" would be engineering specifications and regulatory standards.
8. The sample size for the training set
- Training Set Sample Size: Not applicable. This document describes a medical device (MRI coil), not a machine learning or AI algorithm. Therefore, there is no "training set" in the context of algorithm development. The non-clinical testing and image review are for validation/verification, not training.
9. How the ground truth for the training set was established
- Ground Truth for Training Set: Not applicable, as there is no training set for this hardware 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.