(24 days)
GBrain MRI is a post processing medical device software intended for analyzing and quantitatively reporting signal hyperintensities in the brain on T2w FLAIR MR images and T1w post contrast images in the context of diagnostic radiology.
GBrain MRI is intended to provide automatic segmentation, quantification, and reporting of derived image metrics. It is not intended for detection or specific diagnosis of any disease nor for the detection of signal hyperintensities.
GBrain MRI should not be used in-lieu of a full evaluation of the patient's MRI scans. The physician retains the ultimate responsibility for making the final patient management and treatment decisions.
GBrain MRI is a non-invasive MR imaging post-processing medical device software that aids in the volumetric quantification of hyperintensities in T2-weighted Fluid Attenuated Inversion Recovery (T2w FLAIR), and in post contrast T1-weighted (T1c) brain MR images. It is intended to aid the trained radiologist in quantitative measurements.
The input to the software are the T2w FLAIR and the T1w post contrast brain MR images.
The outputs are volume measurements in Secondary Capture DICOM format, a DICOM Encapsulated pdf file, as well as a DICOM SR. More specifically, the total volume of hyperintensities in the input T2w FLAIR and the T1c are shown in two new secondary capture image series, called GBrain T2 FLAIR & GBrain T1 CE respectively, with a segmentation overlay on the hyperintensities that were used to measure the total volumes. These volume measurements are summarized in the DICOM encapsulated pdf and DICOM SR files.
The outputs are provided in standard DICOM format that can be displayed on most third-party DICOM workstations and Picture Archive and Communications Systems (PACS).
The software is suitable for use in routine patient care as a support tool for radiologists in assessment of structural adult brain MRIs, by providing them with complementary quantitative information.
The GBrain MRI processing architecture includes a proprietary automated internal pipeline that performs skull stripping, signal normalization, segmentations, volume calculations, and report generation.
From a workflow perspective, GBrain MRI is packaged as a computing appliance that is capable of supporting DICOM file transfer for input, and output of results. The software is designed without the need for a user interface after installation. Any processing errors are reported either in the output series report, or in the system log files.
GBrain MRI software is intended to be used by trained personnel only and is to be installed by trained technical personnel.
Quantitative reports and derived image data sets are intended to be used as complementary information in the review of a case.
The GBrain MRI software does not have any accessories or patient contacting components.
The GBrain MRI device is intended to be used for the adult population only.
Here's a summary of the acceptance criteria and the study that proves the device meets them, based on the provided FDA 510(k) Clearance Letter.
Acceptance Criteria and Device Performance
1. Table of Acceptance Criteria and Reported Device Performance
| Metric | Acceptance Criteria (Lower Bound of 95% CI) | Reported Device Performance (Lower Bound of 95% CI) |
|---|---|---|
| Volume Measurement (R²) | N/A (explicit value not stated, but implied by "passed planned acceptance criteria") | 0.94 (Contrast Enhancement) |
| Segmentation Overlap (Dice Similarity Coefficient) | N/A (explicit value not stated, but implied by "passed planned acceptance criteria") | 0.81 (Contrast Enhancement) |
| Reproducibility (R²) | N/A (explicit value not stated, but implied by "passed planned acceptance criteria") | 0.92 |
Note: While explicit acceptance values for R² and Dice were not provided in the document, the statement "passed the planned acceptance criteria" indicates that the reported performance values met the internal thresholds set by the manufacturer.
Study Details
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size (Test Set): 131 patient cases for Contrast Enhancement measurements.
- Data Provenance:
- Country of Origin: United States (collected from four separate hospital systems in Alabama, Florida, Kentucky, and California).
- Retrospective/Prospective: Not explicitly stated, but "collected from four separate hospital systems" and "external dataset used for validation was independent from the internal training datasets" typically implies a retrospective collection of existing data.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
- Number of Experts: Three independent experts.
- Qualifications: US board-certified, experienced neuroradiologists.
4. Adjudication Method for the Test Set
- Method: Simultaneous Truth and Performance Level Estimation (STAPLE) algorithm was used to generate a consensus ground truth from the three expert-labeled segmentations. This effectively acts as an automated adjudication method.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
- No. The document describes a "standalone" performance evaluation of the algorithm against expert-derived ground truth, not a comparative effectiveness study involving human readers with and without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
- Yes. The performance testing described focuses on comparing the software's segmentations to expert segmentations, indicating a standalone evaluation of the algorithm's accuracy.
7. The Type of Ground Truth Used
- Type: Expert consensus, specifically using the STAPLE algorithm to combine three independent expert-labeled segmentations.
8. The Sample Size for the Training Set
- Not explicitly stated. The document mentions the validation dataset was "independent from the internal training datasets" but does not specify the size of the training datasets.
9. How the Ground Truth for the Training Set Was Established
- Not explicitly stated. The document mentions "internal training datasets" but does not detail the method for establishing their ground truth. Given the validation approach, it's highly probable that similar expert-derived ground truth methods were used for training data, but this is an inference rather than a direct statement.
§ 892.2050 Medical image management and processing system.
(a)
Identification. A medical image management and processing system is a device that provides one or more capabilities relating to the review and digital processing of medical images for the purposes of interpretation by a trained practitioner of disease detection, diagnosis, or patient management. The software components may provide advanced or complex image processing functions for image manipulation, enhancement, or quantification that are intended for use in the interpretation and analysis of medical images. Advanced image manipulation functions may include image segmentation, multimodality image registration, or 3D visualization. Complex quantitative functions may include semi-automated measurements or time-series measurements.(b)
Classification. Class II (special controls; voluntary standards—Digital Imaging and Communications in Medicine (DICOM) Std., Joint Photographic Experts Group (JPEG) Std., Society of Motion Picture and Television Engineers (SMPTE) Test Pattern).