(84 days)
Your MAGNETOM system is indicated for use as a magnetic resonance diagnostic device (MRDD) that produces transverse, sagittal, coronal and oblique cross sectional images and/or spectra, and that displays the internal structure and/or function of the head, body, or extremities. Other physical parameters derived from the images and/or spectra may also be produced. Depending on the region of interest, contrast agents may be used. These images and the physical parameters derived from the images and/or spectra, when interpreted by a trained physician, yield information that may assist in diagnosis.
Your MAGNETOM system may also be used for imaging during interventional procedures when performed with MR compatible devices such as in-room display and MR-Safe biopsy needles.
Software syngo MR E11E with Ischemic Heart Disease (HD) Workflow, when used with a gadolinium-based contrast agent (GBCA) approved for cardiac MRI (CMRI) is indicated for the acquisition and display of images of myocardial perfusion (stress, rest) and late gadolinium enhancement (LGE) during post-contrast CMRI examination in patients with known or suspected coronary artery disease (CAD).
MAGNETOM Aera and MAGNETOM Skyra with Software syngo MR E11E with IHD Workflow are the subject devices. The Software syngo MR E11E with IHD Workflow, when used with a gadolinium-based contrast agent (GBCA) approved for CMRI, extends the capability of the cleared Cardiac Dot Engine (K121434) for post-contrast CMRI exams for patients with known or suspected coronary artery disease (CAD). Software syngo MR E11E with IHD Workflow is available for MAGNETOM Aera and MAGNETOM Skyra excluding the 24-channel configuration.
A. The cleared Cardiac Dot Engine (syngo MR D13A, K121434) helps acquisition and display of cardiac morphology and function (noncontrast CMRI).
A comprehensive post-contrast CMRI exam includes stress/rest perfusion and late gadolinium enhanced (LGE) imaging. To accomplish post-contrast CMRI imaging, basic morphologic / functional imaging (noncontrast CMRI) is required. Therefore, the cleared Cardiac Dot Engine (syngo MR D13A, K121434) is a pre-requisite to the subject devices.
B. The Cardiac Dot Engine together with the IHD Workflow and a GBCA approved for post-contrast CMRI provides for a complete (pre- and post-contrast) examination.
The primary predicate devices are modified to include a new Dot Workflow named "Ischemic Heart Disease" (IHD) Workflow for a post-contrast CMRI exam using pulse sequences already cleared in the USA (syngo MR D13A, K121434). A new Dot Workflow "Ischemic Heart Disease" is added in Cardiac Dot Engine dropdown list, under the region "heart". This Dot Workflow includes the following: six new post-contrast CMRI measurement protocols and one workflow step:
New Measurement protocols:
- DynamicTest (test protocol for perfusion imaging without contrast agent)
- DynamicStress (protocol for perfusion imaging under stress conditions)
- DynamicRest (protocol for perfusion imaging under rest conditions)
- DE overview (protocol for delayed enhancement (DE) or LGE with low spatial resolution as an overview)
- DE_seg_high-res_LAX (protocol for DE or LGE with high spatial resolution in long axis view)
- DE seg high-res SAX (protocol for DE or LGE with high spatial resolution in short axis view)
New workflow step:
- Inject contrast agent. This step prompts the user to start the contrast agent injection for post-contrast CMRI exams.
This document describes the regulatory approval for the Siemens MAGNETOM Aera and MAGNETOM Skyra with Software syngo MR E11E with Ischemic Heart Disease (IHD) Workflow. The IHD Workflow is an extension to the cleared Cardiac Dot Engine, intended for post-contrast Cardiac MRI (CMRI) exams for patients with known or suspected Coronary Artery Disease (CAD).
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of acceptance criteria or quantitative performance metrics for the IHD Workflow. Instead, it refers to the efficacy results of two clinical studies (GadaCAD1 and GadaCAD2) to support the device's performance. The "acceptance criteria" can therefore be inferred as the successful demonstration of the device's ability to acquire and display myocardial perfusion and late gadolinium enhancement (LGE) images that adequately detect CAD when interpreted by qualified readers.
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| Ability to acquire and display images of myocardial perfusion (stress, rest) and late gadolinium enhancement (LGE) during post-contrast CMRI examination for interpretation by trained physicians. | The GadaCAD studies demonstrated that the device generated CMRI images (stress and rest perfusion and LGE) that were interpreted by qualified independent readers to adequately detect CAD. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: A total of 764 subjects were evaluated across two studies: 376 subjects in GadaCAD1 and 388 subjects in GadaCAD2. These subjects represent the test set for evaluating the post-gadobutrol CMRI capabilities.
- Data Provenance: The GadaCAD studies were prospectively controlled, multi-national, single-arm clinical studies. The document states that they were performed by Bayer HealthCare AG.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Experts
- Number of Experts: The document states that the CMRI images were "interpreted by qualified independent readers". While it doesn't specify an exact number, the use of "readers" (plural) across multi-center, multi-national studies implies multiple experts were involved in the interpretation process.
- Qualifications of Experts: The readers were described as "radiologists and cardiologists experienced in CMRI".
4. Adjudication Method for the Test Set
The document does not explicitly describe an adjudication method (e.g., 2+1, 3+1 consensus) for establishing the ground truth from the expert interpretations in the GadaCAD studies. It simply states that the images were "interpreted by qualified independent readers." The primary endpoint of the GadaCAD studies, as mentioned in the GADAVIST™ package insert, was likely the diagnostic accuracy of CMRI for CAD detection, which would have implicitly relied on these interpretations, but the specific consensus mechanism is not detailed.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- The document does not describe a multi-reader multi-case (MRMC) comparative effectiveness study designed to assess the improvement of human readers with AI vs. without AI assistance.
- The IHD Workflow is presented as a set of modified measurement protocols and a workflow step for image acquisition and display, extending the capabilities of the existing Cardiac Dot Engine. The clinical studies evaluated the efficacy of the imaging technique itself (using the IHD Workflow components) for CAD detection, not the comparative performance of human readers with and without AI assistance for interpretation.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
- The document does not present a standalone performance study for an algorithm without human-in-the-loop performance.
- The IHD Workflow focuses on image acquisition and display protocols. The interpretation of these images for diagnosis still relies on "trained physicians." The clinical studies validate the acquisition and display capabilities to produce images sufficient for expert interpretation.
7. Type of Ground Truth Used
The ground truth used in the GadaCAD studies was expert consensus / clinical interpretation by qualified independent readers (radiologists and cardiologists experienced in CMRI) for the detection of CAD. The document explicitly states: "The post-gadobutrol CMRI specific acquisition protocols supported adequate detection of CAD in two multi-center, multinational clinical studies."
8. Sample Size for the Training Set
The document does not provide information on the sample size used for the training set. The IHD Workflow's development and validation are largely described in terms of non-clinical software verification and validation, and clinical validation using the GadaCAD studies. The GadaCAD studies served as the validation set for the device's performance, not a training set for an AI/algorithm component requiring labeled data for learning. The IHD Workflow primarily introduces new measurement protocols and a workflow step, not necessarily a machine learning algorithm that requires a distinct training set in the conventional sense.
9. How Ground Truth for the Training Set Was Established
Since no training set is explicitly mentioned or relevant for the described IHD Workflow (which consists of acquisition protocols and workflow steps, not an AI model requiring a training phase), the method for establishing ground truth for a training set is not applicable/not provided in this document.
§ 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.