(54 days)
The Medrad Quadrature CTL Coil is a receive only coil intended to be used with the General Electric Superconducting MRI Scanners. This coil is intended to facilitate complete MR imaging of the cervical, thoracic and lumbar regions of the spine without need of patient repositioning of the device.
The Medrad Quad CTL Array Coil is intended for use only under the supervision of a Physician trained in the use of Diagnostic Magnetic Resonance Imaging.
The Medrad Quad CTL Array Coil is a receive only coil designed to enhance the MR Imaging of the thoracic and lumbar regions of the spine anatomy.
The provided document describes a 510(k) premarket notification for the Medrad Quadrature CTL Array Coil, a receive-only coil designed for MRI imaging of the spine. The evaluation focuses on demonstrating substantial equivalence to predicate devices rather than proving specific performance against predefined acceptance criteria for a new clinical indication or algorithm. Therefore, many standard elements of an AI/algorithm acceptance study are not applicable or explicitly mentioned.
Here's an analysis of the available information:
1. Table of Acceptance Criteria and Reported Device Performance
Formal, quantifiable acceptance criteria (e.g., sensitivity, specificity, accuracy thresholds) are not defined in this 510(k) submission. The performance evaluation is primarily comparative and qualitative, focusing on physical and image quality characteristics relevant to an MRI coil.
| Performance Parameter | Acceptance Criteria (Implied/Compared) | Reported Device Performance |
|---|---|---|
| Signal to Noise Ratio (SNR) | Comparable to predicate devices, or sufficient for intended diagnostic use (not explicitly quantified). | An SNR study was conducted to generate the SNR of the proposed Medrad 1.0T QUADRATURE CTL ARRAY Coil. Direct comparison to predicate devices was not possible due to different platforms. |
| Image Uniformity | Meets NEMA Standards for non-uniformity. | The Medrad Quad CTL Array Coil was evaluated using NEMA Standards to characterize the non-uniformity. Contours of axial and sagittal images were constructed. (Implies it met NEMA standards as no non-compliance is reported). |
| Geometric Distortion | None observable. | None. "No observable distortion of the static magnetic field is present." (This device contains slightly magnetic materials, but their placement prevents distortion.) |
| Transmit RF Field [B1] Distortion | No artifacts observed; no significant induced currents. | "No artifacts of any type were observed during imaging." (Analysis of electrical design showed no significant currents are induced.) |
| Resolution, Slice Thickness, Contrast | Not affected by surface coil. | "These performance parameters are not affected by the use of a surface coil and were not separately tested..." |
| Clinical Effectiveness | Produces similar clinical image results to predicate devices. | "Clinical images for the proposed 1.0T Quad CTL Array Coil have been provided... to demonstrate the clinical effectiveness." "Based on these results, and the SNR results... Medrad concludes that the 0.5T and 1.0T Quad CTL Array Coils will produce similar clinical image results." |
| Safety and Durability | Demonstrated in predicate devices, and implied for the proposed device through substantial equivalence claim and material comparison (housing, comfort pad). | Extensively conducted on predicate devices (K954952, K902663, K960901). The proposed device's materials were compared to predicates. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: Not explicitly stated. The "Clinical Evaluation" mentions "Clinical images" were provided, implying a small set of images, but the number of patients or images is not quantified.
- Data Provenance: Not specified. It's likely prospective data for the clinical evaluation, as the intent is to showcase the new device. The country of origin is not mentioned but assumed to be the United States, given the FDA submission.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This information is not provided. The clinical evaluation seems to rely on the general "clinical effectiveness" demonstrated by the provided images, likely assessed by the manufacturer's internal team, but no details on expert review or ground truth establishment are given.
4. Adjudication Method for the Test Set
This information is not provided. Given the nature of an MRI coil and the 510(k) submission, formal adjudication methods like 2+1 or 3+1 for diagnostic accuracy are typically not relevant here. The "clinical evaluation" would likely involve visual assessment for image quality and utility.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC comparative effectiveness study was not done. The study conducted was primarily a technical and basic image quality assessment of the device itself, leading to a claim of substantial equivalence. The document does not describe human reader performance or improvements with or without AI assistance, as this is an MRI coil, not an AI diagnostic algorithm.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, in essence. The "Performance Test Data" section describes evaluations of the coil itself (SNR, image uniformity, geometric distortion, B1 distortion) without human interpretation as part of the primary test. The "Clinical Evaluation" section then presents images, which are inherently "standalone" output of the device, for visual assessment of "clinical effectiveness."
7. The Type of Ground Truth Used
The ground truth for the performance test data is based on physical measurements and NEMA standards (for SNR and image uniformity). For "clinical effectiveness," it's based on the visual assessment of images produced by the coil, implicitly compared to expected clinical image quality from existing devices. There's no mention of pathology or outcomes data being used as ground truth for a diagnostic claim.
8. The Sample Size for the Training Set
This information is not applicable as this is not an AI/machine learning algorithm. The coil design and testing do not involve a "training set" in that context.
9. How the Ground Truth for the Training Set Was Established
This information is not applicable as there is no training set for this medical 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.