(85 days)
The Medrad Phased Array 1.5T Shoulder Imaging Surface Coil is for use only with the GEMS family of Super Conductor MR Systems. An anterior loop pair is combined with a posterior loop. The coil is designed to receive RF excitation from the protons of the hydrogen nuclei as a result of the scanner exciting these protons. The coil is designed for anatomical imaging of either the right or left shoulder region with a specific size and shape to facilitate placement on the anatomy area of interest. This placement results in a higher Signal To Noise Ratio(SNR) in the region near the surface coil. The greater SNR permits more effective imaging through the use of a smaller FOV and thinner slices,
The intended ROI for imaging includes the anterior and posterior musculoskeletal area of the shoulder. This includes the rotator cuff, humeral head, glenoid, glenoid labrum and glenoid cavity. The region runs superior through the clavicle and acromion and inferior through the infraspinatus. It also extends posterior to the lateral marqin.
The Medrad Phased Array 1.5T Shoulder Imaging Surface Coil is intended for use in physician diagnosis of impingement syndrome, glenoid labrum tendon tears, rotator cuff tears, edema secondary to the aforementioned, retraction of the supraspinatus muscle and trauma of the long head of the biceps tendon.
Patient fitness and suitability for MRI must be determined by the individual physician trained in the field of Diagnostic Magnetic Resonance Imaging.
The Medrad Phased Array 1.5T Shoulder Imaging Surface Coil is a rigid RF receive only magnetic field pickup coil that is designed to enhance imaging of the human shoulder and associated anatomic region. It consist of an anterior loop contoured to comfortably fit the anterior aspect of the right or left shoulder. The anterior loop cable interfaces with the multi-coil port on the GEMS Signa System. The coil is intended for use in all imaging planes, with a field of view(FOV) of at least 12 centimeters and less than 25 centimeters.
The Medrad Phased Array 1.5T Shoulder Imaging Surface Coil is designed to provide high resolution diagnostic images under the supervision of a physician who is trained in the field of Diagnostic Resonance Imaging.
The ABS outer housing of the coil has been designed to provide an enduring enclosure for the coil electrical components. Durability tests are conducted to verify the integrity of the coil structure. Additionally, the coil will not contain any ferrous nickel, ferrite or other magnetic materials which would negatively impact coil performance. The coil is also designed to assure that the components of the coil that come into contact with the patient will not have surface temperatures exceeding 41 degrees Celsius as a result of heating due to dielectric losses.
In summary, the Medrad Phased Array 1.5T Shoulder Imaging Surface Coil utilizes a combination of the proven phased array technology of previous MRI surface coils such as the predicate Signa Phased Array 1.5T Breast Imaging Surface Coil, and the equivalent anatomical region surface imaging as demonstrated with the predicate Signa Linear 1.5T Shoulder Coil.
This document is a 510(k) premarket notification for a medical device, which typically focuses on demonstrating substantial equivalence to a predicate device rather than presenting a full clinical study with acceptance criteria and detailed performance metrics as would be seen in a more extensive clinical trial or research paper. Therefore, the information provided is limited in these aspects.
Here's an attempt to populate the requested information based on the provided text, with explicit notes where information is not available:
Acceptance Criteria and Device Performance for Medrad Phased Array 1.5T Shoulder Imaging Surface Coil
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Criteria (Implicitly based on predicate device & NEMA) | Reported Device Performance |
|---|---|---|
| Signal-to-Noise Ratio (SNR) | Increased SNR compared to the predicate Linear Surface Coil (K892235) | "Increased SNR" verified (specific numeric increase not provided) |
| Image Non-Uniformity | Characterized non-uniformity per NEMA standards | Contours constructed for axial, sagittal, and coronal images (specific non-uniformity metrics not provided) |
| Temperature Rise (Safety) | Surface temperatures not exceeding 41 degrees Celsius | "Temperature rise test results under moderate duty cycle scan conditions" conducted (specific results not provided, but implicitly met the criteria). |
| Dielectric Strength (Safety) | Meet IEC 601-1 dielectric strength standards | "IEC 601-1 dielectric strength test results" produced (specific results not provided, but implicitly met the criteria). |
| Morphological Detail | Improved morphological detail compared to the predicate Linear Surface Coil (K892235) | "Improved morphological detail" substantiated |
| Image Clarity | Improved image clarity compared to the predicate Linear Surface Coil (K892235) | "Image clarity" demonstrated |
| Durability | Integrity of the coil structure verified | "Durability tests are conducted to verify the integrity of the coil structure." (specific results not provided, but implicitly met the criteria). |
| Material Composition | No ferrous nickel, ferrite or other magnetic materials negatively impacting performance | "The coil will not contain any ferrous nickel, ferrite or other magnetic materials which would negatively impact coil performance." (statement of design, not test result) |
2. Sample size used for the test set and the data provenance
- Sample Size (Test Set): Not explicitly stated numbers for human subjects. The text mentions "Images were obtained for both the proposed Medrad Phased Array 1.5T Shoulder Imaging Surface Coil and the predicate Linear 1.5T Shoulder Coil". It also refers to "a loaded phantom" for SNR evaluation. This implies a very limited number of human subjects, if any, for comparison and possibly a single phantom for engineering tests.
- Data Provenance: Not explicitly stated (e.g., country of origin). The studies appear to be internal tests conducted by Medrad.
- Retrospective or Prospective: Not explicitly stated, but given the context of a 510(k) submission and "clinical testing" without a large-scale trial, it's likely a small prospective series of image acquisitions for comparison purposes rather than a robust retrospective or prospective observational study.
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.
- Qualifications of Experts: Not explicitly stated. The device is intended for use "under the supervision of a physician who is trained in the field of Diagnostic Resonance Imaging," suggesting that such qualified radiologists would be involved in assessing image quality, but specific details are absent.
4. Adjudication method for the test set
- Adjudication Method: Not explicitly stated. The comparisons appear to be direct qualitative assessments of "increased SNR" and "improved morphological detail." It is not described whether multiple readers were involved or if there was a formal adjudication process beyond a qualitative statement.
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, an MRMC study was NOT done. This device is a hardware component (MRI surface coil), not an AI algorithm. Therefore, the concept of "human readers improve with AI vs without AI assistance" is not applicable.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Standalone Performance Test: Not applicable. This is a hardware device (MRI surface coil), not an algorithm. Its "performance" is inherent to the image acquisition process, which always involves a human operator and physician interpretation. The "algorithm" here would be the MR scanner's reconstruction algorithms, which are not the subject of this 510(k).
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- Type of Ground Truth: The "ground truth" for evaluating the coil's performance is primarily qualitative assessment of image quality by experts (presumably radiologists) and quantitative measurements of physical properties like SNR, non-uniformity from phantoms, and safety parameters (temperature, dielectric strength). It is not pathology or outcomes data, as the coil itself doesn't provide a diagnosis but rather improves the quality of images from which a diagnosis can be made.
8. The sample size for the training set
- Sample Size (Training Set): Not applicable in the context of this hardware device. The concept of a "training set" typically applies to AI algorithms that learn from data. This device is an engineered product, not a learned model.
9. How the ground truth for the training set was established
- Ground Truth for Training Set: Not applicable (see point 8).
§ 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.