(27 days)
The 1.5T T/R Quad Extremity Coil is intended to be used in conjunction with a SIGNA Prime Magnetic Resonance Scanner to produce diagnostic images of the lower extremities that can be interpreted by a trained physician.
The 1.5T 8CH T/R Knee Coil is intended to be used in conjunction with a SIGNA Prime Magnetic Resonance Scanner to produce diagnostic images of the knee that can be interpreted by a trained physician.
The 1.5T T/R Quad Extremity Coil is quadrature Transmit and Receive coils. At 1.5T the coil can be used in 3 different operational modes: QuadKnee, QuadFoot and QuadAnkle. The coil is designed to image the Knee, Foot and Ankle, but can also be used for other parts of the lower extremities. The base of the coil is attached to a base plate and can be moved to scan either the Left or Right extremity. The coil is moved into position (Left to Right) and locked into place, the patient is then positioned in the base, the top section of the coil is placed over the patient and the latched closed. The fixed position of the coil and helps prevent the patient form moving, reducing artifact. This coil is used independently and can't be combined with any other coils. The 1.5T T/R Quad Extremity Coil is compatible with SIGNA Prime MRI Systems with P-Port Connector. It consists of a birdcage quadrature coil. During transmit phase, the coil is resonated by the RF power source of MR system, to excite hydrogen nuclei (protons) in the anatomy. The quadrature coil detects the magnetic resonance signals generated by hydrogen nuclei (protons) in the knee during the receive phase. The coil is tuned to transmit and receive RF frequency corresponding to the proton precession in a 1.5 tesla magnetic field, which is governed by the Larmor equation.
The 1.5T 8CH T/R Knee Coil is an 8 element phase array coil with a T/R quadrature birdcage shell, designed to image the knee. The base of the coil is attached to a base plate and can be moved to scan either the Left or Right Knee. The patient is positioned in the base, the top section of the coil is placed over the patient and the latched closed, which locks the position of the coil and helps prevent the patient form moving, reducing artifact. The transmit shell consist of a twist birdcage quadrature coil, resonated by the RF power source of MR system, to excite hydrogen nuclei (protons) in the anatomy. The coil receivers consist of 8 phased array elements that detect the magnetic resonance signals generated by hydrogen nuclei (protons) in the knee while blocking the high-frequency B1 field applied by the coil transmit shell at specified timings. The coil is tuned to transmit and receive RF frequency corresponding to the proton precession in a 1.5 tesla magnetic field, which is governed by the Larmor equation. This coil is used independently and cannot be combined with any other coils.
The 1.5T T/R Quad Extremity Coil and 1.5T 8CH T/R Knee Coil are compatible with SIGNA Prime MRI systems with a P-Port connector.
Here's an analysis of the acceptance criteria and study information provided for the 1.5T T/R Quad Extremity Coil and 1.5T 8CH T/R Knee Coil:
1. Table of Acceptance Criteria and Reported Device Performance
The provided document primarily focuses on demonstrating substantial equivalence to predicate devices and adherence to recognized standards. It doesn't explicitly list specific numerical acceptance criteria (e.g., minimum SNR values, specific image quality scores) prior to presenting performance results. Instead, the acceptance criterion for the clinical performance seems to be that the generated images are "of sufficient quality for diagnostic use."
| Category | Acceptance Criteria (Stated or Implied) | Reported Device Performance |
|---|---|---|
| Non-Clinical Safety & Performance | ||
| Electrical Safety | Compliance with ANSI/AAMI ES 60601-1 and IEC 60601-2-33 (General electrical/mechanical safety) | Testing conducted and results are stated to "meet the acceptance criteria." Implicitly, the device met these standards. |
| EMC Immunity | Compliance with IEC 60601-1-2 (EMC Immunity, electrostatic discharge testing) | Testing conducted and results are stated to "meet the acceptance criteria." Implicitly, the device met this standard. |
| Surface Heating | Compliance with NEMA MS 14 | Testing conducted and results are stated to "meet the acceptance criteria." Implicitly, the device met this standard. |
| Image Quality (SNR & Uniformity) | Compliance with NEMA MS-1, NEMA MS-3, NEMA MS-9 and IEC 62464-1 (Image Signal to Noise and Image Uniformity characterization) | Testing conducted and results are stated to "meet the acceptance criteria." Implicitly, the device demonstrated sufficient SNR and image uniformity. Results for image signal to noise and image uniformity were characterized, which implies they were measured and found acceptable. |
| Specific Absorption Rate (SAR) | Compliance with IEC 60601-2-33 and NEMA MS-8 | Testing conducted and results are stated to "meet the acceptance criteria." Implicitly, the device met these standards. |
| Biological Safety | Compliance with ISO 10993-1 | Testing conducted and results are stated to "meet the acceptance criteria." Implicitly, the device met this standard. |
| Cleaning & Disinfection | Compliance with ISO 17664 (Cleaning and disinfection validations to support reprocessing instructions) | Testing conducted and results are stated to "meet the acceptance criteria." Implicitly, the device's reprocessing instructions were validated. |
| Clinical Performance | Images produced are of "sufficient quality for diagnostic use" as interpreted by a trained physician. No adverse events reported during testing. | Sample clinical images for target anatomical locations (lower extremities for Quad Extremity Coil, knee for 8CH Knee Coil) were provided in DICOM format and reviewed by a US Board Certified radiologist, who provided a statement supporting the device's ability to generate diagnostic quality images. No adverse events were reported. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document does not specify a numerical sample size for the clinical test set (i.e., how many patients or images were used). It only mentions "Sample clinical images" were provided.
- Data Provenance: The document does not explicitly state the country of origin for the clinical data or whether it was retrospective or prospective. It only mentions the radiologist being "US Board Certified."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Number of Experts: One "US Board Certified radiologist" was used.
- Qualifications of Experts: A "US Board Certified radiologist." No information is provided regarding their years of experience.
4. Adjudication Method for the Test Set
- Adjudication Method: Not explicitly stated. Since only one radiologist is mentioned as evaluating the images and providing a statement, an adjudication method like 2+1 or 3+1 was likely not used. It appears to be a single-reader assessment of diagnostic quality.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No, an MRMC comparative effectiveness study was not done. The study's purpose was to demonstrate that the new coils produce diagnostic quality images, not to compare human reader performance with and without AI assistance (as this is a coil, not an AI device). Therefore, no effect size of human reader improvement with AI vs. without AI assistance is applicable or reported.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Yes, in spirit, a form of standalone performance was assessed for the device's output. The devices are MRI coils, which produce images. The "performance testing" of NEMA standards (SNR, uniformity) assessed the intrinsic image quality generated by the coils themselves (the "algorithm only" equivalent for hardware). The clinical performance involved a radiologist interpreting "images produced," implying a standalone evaluation of the image quality delivered by the coil system.
7. The Type of Ground Truth Used
- Expert Consensus (single expert): For clinical performance, the ground truth was established by the statement of a single "US Board Certified radiologist" who confirmed the images were of "sufficient quality for diagnostic use."
- Physical/Technical Standards: For non-clinical performance, the ground truth was adherence to recognized consensus standards (e.g., ANSI/AAMI ES 60601-1, IEC 60601-1-2, NEMA MS-1).
8. The Sample Size for the Training Set
- Not Applicable. The devices are physical MRI coils, not an AI algorithm that undergoes a "training set." Therefore, there is no training set sample size to report.
9. How the Ground Truth for the Training Set Was Established
- Not Applicable. As these are physical medical devices (MRI coils), there is no training set or ground truth establishment relevant to an AI/machine learning model. The devices are engineered and tested against established physical and safety standards.
§ 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.