(31 days)
The Sentinelle Breast MRI tabletop with 16 Channel Coil Array for Siemens 1.5T/3T MRI Systems is designed to provide magnetic resonance images of breast anatomy when used in conjunction with a Magnetic Resonance Scanner. These images are interpreted by a trained physician. When used with a disposable sterile plate (biopsy grid), the device permits access to breast anatomy for biopsy and localization procedures.
The Sentinelle Breast MRI Tabletop with 16 Channel Coil Array for Siemens 1.5/3T MRI Systems is a receive-only MRI imaging coil and interventional system for breast anatomy. The system consists of a tabletop which supports the patient and imaging coils which provide a means of enabling interventional device guidance. The tabletop, like other breast coils provides an aperture to admit the breasts and provides the physician access to the breast(s). This aperture enables the guidance of interventional devices (such as biopsy needles), when performing a biopsy. The tabletop's compression system facilitates immobilization of the breast for imaging and interventional procedures and serves to hold the individual imaging coils in proximity to the breast(s). Compression plates (also referred to as immobilization plates) provided with the system are held in frames, which may be positioned in the left-right and anteriorposterior directions and fixed in place to gently immobilize one or both breasts for interventional procedures. When performing a stereotactic interventional procedure (such as biopsy or wire localization), one or more compression plates may be interchanged for a sterile, single use, disposable fenestrated plate (also referred to as biopsy grid) cleared under FDA 510(k) Number: K060873. The biopsy grid contains apertures that permit the physician to access the breast for intervention, while minimizing tissue motion. When performing biopsy and/or imaging of a single breast, the system may be used with two compression plates immobilizing that breast. The contralateral breast support prevents the contralateral breast from interfering with medial-approach interventions. When imaging both breasts, a medial coil element is used between the breasts in conjunction with two lateral coils. The tabletop's receive-only coil system acts to passively collect RF emissions from the nuclei excited by the MRI. The Sentinelle phased array breast coil set consists of 2, 10 or 16 RF coil elements in a phased array design. The coil elements and electronics are enclosed in a rigid housing that is resistant to fluid ingress and is fire retardant. The coils are positioned close to the patient's breast during imaging. This receive-only coil is designed to give an improved signal-to-noise ratio, image resolution and image acquisition over that of a standard body coil.
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Device: Sentinelle Breast MRI Tabletop with 16 Channel Coil Array for Siemens 1.5/3T MRI Systems
1. Table of Acceptance Criteria and Reported Device Performance
The provided document defines acceptance criteria primarily through a comparison to a predicate device and extensive verification and validation testing, ensuring safety and performance are substantially equivalent. The acceptance criteria are implicit in the comparison to the predicate and the successful completion of a comprehensive set of tests. The reported device performance is indicated by the successful completion of these tests and a finding of substantial equivalence.
| Acceptance Criteria Category | Specific Acceptance Criteria (Inferred from Predicate and Testing) | Reported Device Performance (from Test Conclusion) |
|---|---|---|
| Intended Use | Provides magnetic resonance images of breast anatomy when used with a Magnetic Resonance Scanner; images are interpreted by a trained physician. Permits access for biopsy/localization with sterile plate. (Matches predicate) | The system performed as intended. |
| Design & Technology | Supports patient prone, receive-only antennas, compression plates for immobilization, non-ferrous materials. (Matches predicate) | Substantially equivalent to predicate. |
| Materials | Flame retardant Polycarbonate, Acetal Resin, Polyurethane; biocompatibility evaluated. (Matches predicate) | Substantially equivalent to predicate. |
| Coil Design | 16, 10, or 2 loop phased array, receive-only. (Matches predicate) | Substantially equivalent to predicate. |
| Decoupling | Active PIN Diode switching, passive blocking. (Matches predicate) | Substantially equivalent to predicate. |
| RF Burn Prevention | Cables cannot be looped. (Matches predicate) | Substantially equivalent to predicate. |
| RF Absorption | Receive-only coil, does not transmit RF power. Power deposition limited by SAR program of MRI magnet. (Matches predicate) | Substantially equivalent to predicate. |
| Resonant Loop Formation | Decoupling isolates coil elements from RF fields during transmission. (Matches predicate) | Substantially equivalent to predicate. |
| Performance Testing | Determined according to NEMA standards for MRI Coils as applicable to phased array coils. (Matches predicate) | The system performed as intended, demonstrating safety and effectiveness. |
| Safety and Effectiveness | No new safety and effectiveness issues introduced compared to predicate. | No new safety and effectiveness issues were introduced, and the device is safe and effective as the predicate. |
| Compatibility | Compatible with Siemens 1.5T (MAGNETOM Espree) and 3T (MAGNETOM TRIO) MRI Scanners. | Tests confirm compatibility and performance with specified Siemens MRI systems. |
| Specific Performance Metrics | (Implicit in various tests like SNR Evaluation, gMap, Heating & Performance Output, Passive Detuning, Field Distortions, RF Noise, Spike Noise, Switch-Over Tx-Rx, MR Signal from Housing, Body Scout, Voltage Stability) | All conducted tests showed acceptable results, supporting the conclusion of substantial equivalence. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state a numeric "sample size" in terms of patient cases for clinical studies for the "test set" in the traditional sense of AI/clinical trial studies. Instead, the testing involved:
- Phantoms: Used for various technical and performance evaluations (e.g., SNR, gMap, detuning, field distortions, noise).
- Volunteers: Used for "Volunteer Imaging" tests (VAR-02350 for 1.5T, VAR-02363 for 3T).
Data Provenance:
- The tests were conducted in-house by trained testing personnel.
- The use of contrast agent was not used in obtaining the images.
- The tests were performed on the proposed device.
- The nature of the testing (phantom and volunteer imaging for technical parameters) suggests this is prospective data collection specifically for device verification.
- Country of origin is not explicitly stated for individual tests but the manufacturer is based in Canada.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not mention the use of experts to establish "ground truth" for the test set in the context of diagnostic accuracy, as this is a device for image acquisition, not for diagnostic interpretation. The "ground truth" here is implied by objective physical measurements (e.g., signal-to-noise ratios, field distortions) and the observed performance of the device against engineering specifications and NEMA standards.
The phrase "These images are interpreted by a trained physician" in the Indications for Use refers to the subsequent clinical use of the images, not the validation of the device itself.
4. Adjudication Method for the Test Set
Given that the testing focuses on technical performance parameters of an MRI coil rather than diagnostic interpretation, an adjudication method for a diagnostic test set is not applicable and therefore not mentioned. The tests are objective measurements (e.g., SNR values, signal measurements, scout image quality).
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was Done
No, a Multi Reader Multi Case (MRMC) comparative effectiveness study was not done. This type of study focuses on the diagnostic performance of human readers and is not relevant for the type of device (an MRI coil) described in this submission, which is about image acquisition and quality, not interpretation assistance.
6. If a Standalone Study (i.e. algorithm only without human-in-the loop performance) was Done
The entire set of tests performed (Tables 4 and 5) can be considered a standalone study of the device's technical performance. These tests evaluate the coil directly, independent of a human interpreter's diagnostic ability. For example, "SNR Evaluation," "gMap," "Heating and Performance Output," "Passive Detuning Test," "Field Distortions Test," "RF Noise Test," etc., are all standalone performance metrics of the hardware.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
The "ground truth" for this device's validation is based on:
- Engineering Specifications/Standards: Performance measured against NEMA standards and internal functional requirements.
- Physical Measurements: Quantifiable data from phantoms (e.g., SNR ratios, field distortion measurements).
- Visual Assessment: For aspects like "Body Scout" images and "Volunteer Imaging," the "ground truth" is the expected image quality and appearance generated by a properly functioning MRI coil.
No pathology or outcomes data is used as the device is for imaging and intervention guidance, not for diagnosis itself.
8. The Sample Size for the Training Set
The document does not mention a "training set" in the context of an AI algorithm because the device is a hardware component (an MRI coil) and not an AI-powered diagnostic algorithm.
9. How the Ground Truth for the Training Set Was Established
As there is no AI algorithm or training set discussed in the document, this question is not applicable.
§ 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.