(445 days)
Your MAGNETOM system is indicated for use as a magnetic device (MRDD) that produces transverse, sagittal, coronal, and oblique cross sectional images, spectroscopic images 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/or spectra 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.
The subject devices, MAGNETOM Vida with software syngo MR XA31A, and MAGNETOM Vida with syngo MR XA20A, with the new pulse sequence MR Fingerprinting (MRF) consists of slightly modified software that are similar to what is currently offered in the predicate devices, MAGNETOM Vida with syngo MR XA31A (K203443) and MAGNETOM Vida with syngo MR XA20A (K192924) respectively.
The subject devices MAGNETOM Vida with software syngo MR XA31A, and MAGNETOM Vida with synqo MR XA20A includes features that were cleared under K203443 and K192924 respectively. In addition to these features, the subject devices include a new pulse sequence type called MR Fingerprinting (MRF), a method that permits the simultaneous non-invasive quantification mapping of MRF-derived T1 and T2 relaxation times of brain tissue. The MRF is not intended to yield the ground truth T1 and T2 relaxation times of brain tissue.
The document describes the Siemens MAGNETOM Vida MRI system with a new pulse sequence called MR Fingerprinting (MRF). The acceptance criteria for this device and the study proving it meets these criteria are outlined as follows:
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Confirmation of successful MRF execution | MRF T1 and T2 maps from volunteers were acquired, confirming successful execution and absence of obvious artifacts or degradations. |
| Quantitative performance (precision): repeatability and reproducibility of MRF T1 and T2 values | Repeated MRF T1 and T2 maps acquired in phantom and healthy volunteers showed quantitative performance in terms of precision (repeatability and reproducibility). MRF T1 and T2 maps confirmed results were stable and parametric values reproducible across different systems within specified ranges. |
| Software verification and validation | Systematic testing according to MRF test specifications was performed, confirming stability and reproducibility of parametric values. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 3 healthy volunteers were scanned multiple times using multiple systems. Additionally, several clinical patient cases demonstrating a longitudinal use case scenario (repeated scans from the same subject over time) were provided.
- Data Provenance: The document does not explicitly state the country of origin. The study appears to be prospective, as it involved actively scanning volunteers and collecting clinical patient cases for demonstration.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number of experts or their qualifications for establishing ground truth for the provided clinical patient cases or for interpreting the volunteer scans. It states that the device provides "information that may assist in diagnosis" when interpreted by a trained physician, but this is in the general "Indications for Use" and not directly about the ground truth establishment for the performance study.
4. Adjudication Method for the Test Set
The document does not describe any specific adjudication method (e.g., 2+1, 3+1) for the test set.
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 explicitly mentioned as being done to compare human readers with and without AI assistance. The study focuses on the technical performance of the MRF sequence itself.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance evaluation of the MRF sequence was performed. The "Performance bench test" and "Software verification and validation" involved quantitative evaluation of MRF-derived T1 and T2 values in phantoms and volunteers, and testing to confirm stable and reproducible parametric values across systems. This assessment of the algorithm's output without human interpretation is a standalone evaluation.
7. The Type of Ground Truth Used
The ground truth used for the quantitative evaluation of T1 and T2 values came from:
- Quantitative Phantom: For confirming stability and reproducibility of parametric values.
- Healthy Volunteers: For evaluating quantitative performance in terms of precision (repeatability and reproducibility) for T1 and T2 maps.
- The document implies that for the "Sample clinical images" and "clinical patient cases," the assessment was based on whether the sequence executed successfully and produced images free of artifacts, rather than comparing against an external, independent "ground truth" for diagnosis. The MRF itself is described as "not intended to yield the ground truth T1 and T2 relaxation times of brain tissue."
8. The Sample Size for the Training Set
The document does not provide information on the sample size used for the training set for the MRF pulse sequence.
9. How the Ground Truth for the Training Set Was Established
The document does not provide information on how the ground truth for the training set was established, as details about a training set are not included.
§ 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.