(28 days)
The SIGNA 7.0T system is a whole-body magnetic resonance scanner designed to support high signal-tonoise ratio, and short scan times. It is indicated for use as a diagnostic imaging device to produce axial, sagittal, coronal, and oblique images, spectroscopic images, parametric maps, and/or spectra, dynamic images of the structures and/or functions of the head and extremities.
The images produced by the SIGNA 7.0T system reflects the spatial distribution or molecular environment of nuclei exhibiting magnetic resonance. These images and/or spectra when interpreted by a trained physician yield information that may assist in diagnosis.
The device is intended for patients > 20 kg / 44 lb.
SIGNA 7.0T is a high performance magnetic resonance imaging system designed to support high resolution imaging at 7.0T in particular anatomical regions determined by the available RF coils. The system includes a 7.0T superconducting magnet and an ultra-high performance gradient coil with a 60 cm patient bore, supporting scanning in axial, coronal, sagittal, oblique, and double oblique planes using a variety of pulse sequences, imaging techniques, acceleration methods, and reconstruction algorithms.
This 510(k) submission is for the SIGNA 7.0T MR System, and has been triggered by the addition of the AIR Recon DL software feature and inclusion of installed base magnet system upgrades.
The provided text describes a 510(k) submission for the GE SIGNA 7.0T MRI system, specifically focusing on the addition of the AIR Recon DL software feature. While it discusses performance testing and a reader study, it does not explicitly define specific numerical acceptance criteria for the device's performance in a table format, nor does it provide detailed quantitative results against such criteria. The document states that "The nonclinical testing passed the defined acceptance criteria," but these criteria are not enumerated.
However, based on the provided text, we can infer and report on the study details as much as possible:
1. A table of acceptance criteria and the reported device performance
As stated above, no explicit numerical acceptance criteria table is provided in the document. The text broadly states:
- "The nonclinical testing passed the defined acceptance criteria, and did not identify any adverse impacts to image quality or other concerns related to safety and performance."
- "The nonclinical testing demonstrated that AIR Recon DL does improve SNR and image sharpness while maintaining low contrast detectability."
- "Objective measures of in vivo images were analyzed to confirm that AIR Recon DL improves SNR and image sharpness for typical clinical use cases."
- "This study showed that AIR Recon DL feature provides images with better SNR and equivalent or better sharpness."
- "The radiologists uniformly preferred the AIR Recon DL images for clinical evaluation."
2. Sample size used for the test set and the data provenance
- Test Set Sample Size: Not explicitly stated for either the non-clinical or clinical tests. The text mentions "in vivo images" for clinical analysis and "typical clinical use cases," implying a dataset was used, but the size is absent.
- Data Provenance: Not explicitly stated (e.g., country of origin, retrospective/prospective).
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Number of Experts: "Radiologists" (plural), but the exact number is not specified.
- Qualifications of Experts: Only stated as "trained physician" for general image interpretation within the Indications for Use, and "Radiologists" for the reader study. No specific experience levels (e.g., years of experience) are provided for the radiologists in the study.
4. Adjudication method for the test set
- Adjudication Method: Not explicitly stated. The text says "Radiologists were asked to rate the images, and to comment on any notable aspects related to image quality," and that they "uniformly preferred" the AIR Recon DL images. This implies a consensus or preference-based evaluation rather than a formal adjudicated ground truth establishment process for specific findings.
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: Yes, a reader study was performed comparing images "with and without AIR Recon DL feature."
- Effect Size: No quantitative effect size (e.g., magnitude of improvement in diagnostic accuracy, AUC, or other metrics) is provided for how much human readers improved. The improvement is described qualitatively: "The radiologists uniformly preferred the AIR Recon DL images for clinical evaluation." and that images had "better SNR and equivalent or better sharpness."
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
- Standalone Performance: The document describes "nonclinical testing" and "objective measures of in vivo images" where AIR Recon DL's impact on SNR and sharpness was evaluated. This implies an algorithmic evaluation independent of human readers, where the algorithm processes images and its output is analyzed for objective metrics (SNR, sharpness, low contrast detectability). However, specific performance metrics for this standalone performance (e.g., a specific SNR improvement percentage, or sharpness metric) are not quantified in the text.
7. The type of ground truth used
- Clinical Study: For the reader study, the ground truth appears to be based on the radiologists' preference and qualitative assessment of image quality (SNR, sharpness, low contrast detectability) for clinical evaluation. It's not explicitly stated as a definitive "diagnosis" ground truth derived from pathology or outcomes data.
- Non-Clinical/Objective Measures: For objective measures, the "ground truth" aligns with quantifiable physical properties like Signal-to-Noise Ratio (SNR) and image sharpness, which are inherent characteristics of the image output itself. Low contrast detectability was also assessed.
8. The sample size for the training set
- Training Set Sample Size: Not specified in the provided text. The text mentions that "AIR Recon DL has been previously cleared for use with GE Healthcare's 3T SIGNA Premier system through K193282" and that "Due to the technical similarities, SIGNA Premier (K193282) is used as a reference device for this submission." This implies that the algorithm was likely trained on a separate dataset prior to this specific submission, but details of that training set are not in this document.
9. How the ground truth for the training set was established
- Training Set Ground Truth Establishment: Not specified in the provided text.
§ 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.