(90 days)
BriefCase is a radiological computer aided triage and notification software indicated for use in the analysis of non-enhanced head CT and CTPA images. The device is intended to assist hospital networks and trained radiologists in workflow triage by flagging and communication of suspected positive findings of Intracranial Hemorrhage (ICH) and Pulmonary Embolism (PE) pathologies. For the PE pathology, the software is only intended to be used on single-energy exams.
BriefCase uses an artificial intelligence algorithm to analyze images and highlight cases with detected findings on a standalone desktop application in parallel to the ongoing standard of care image interpretation. The user is presented with notifications for cases with suspected findings. Notifications include compressed preview images that are meant for informational purposes only and not intended for diagnostic use beyond notification. The device does not alter the original medical image and is not intended to be used as a diagnostic device.
The results of BriefCase are intended to be used in conjunction with other patient information and based on their professional judgment, to assist with triage/prioritization of medical images. Notified clinicians are responsible for viewing full images per the standard of care.
BriefCase is a radiological computer-assisted triage and notification software device. The software system is based on an algorithm programmed component and is comprised of a standard off-the-shelf operating system, the Microsoft Windows server 2012 64bit, and additional applications, which include PostgreSQL, DICOM module and the BriefCase Image Processing Application. The device consists of the following three modules: (1) Aidoc Hospital Server (AHS); (2) Aidoc Cloud Server (ACS); and (3) Aidoc Worklist Application that is installed on the radiologist' desktop and provides the user interface in which notifications from the BriefCase software are received.
DICOM images are received, saved, filtered and de-identified before processing. Series are processed chronologically by running an algorithm on each series to detect suspected findings and then notifications on flagged series are sent to the Worklist desktop application, thereby prompting preemptive triage and prioritization.
The Worklist Application displays the pop-up text notifications of new studies with suspected findings when they come in. Notifications are in the form of a small pop-up containing patient name, accession number and the relevant pathology (e.g., PE). A list of all incoming cases with suspected findings is also displayed. Hovering over a notification or a case in the worklist pops up a compressed, small black and white, unmarked image that is captioned "not for diagnostic use" and is displayed as a preview function. This compressed preview is meant for informational purposes only, does not contain any marking of the findings, and is not intended for primary diagnosis beyond notification.
Presenting the radiologist with notification facilitates earlier triage by prompting the user to assess the relevant original images in the PACS. Thus, the suspect case receives attention earlier than would have been the case in the standard of care practice alone.
Here's an analysis of the acceptance criteria and the studies conducted for the BriefCase device, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance (PE Pathology)
The document does not explicitly state formal acceptance criteria with specific thresholds prior to the study. However, the "Pivotal Study Summary" mentions a "performance goal" of 80% for both sensitivity and specificity for identifying PE. We will use this as the implicit acceptance criteria.
| Metric | Acceptance Criteria (Performance Goal) | Reported Device Performance (Pivotal Study) | Confidence Interval (95% CI) |
|---|---|---|---|
| Sensitivity | ≥ 80% | 90.6% | 82.2% - 95.9% |
| Specificity | ≥ 80% | 89.9% | 82.2% - 95.1% |
2. Sample Size Used for the Test Set and Data Provenance
- Pivotal Study Test Set: 184 cases (approximately equal number of positive and negative cases)
- Data Provenance (Pivotal Study): Multicenter, multinational study from 3 clinical sites (2 US, 1 OUS). The study was retrospective and blinded.
- Time-to-Notification Study Test Set: 51 True Positive cases (sub-set of cases where both reviewers and BriefCase identified PE)
- Data Provenance (Time-to-Notification Study): 2 medical centers (1 US, 1 OUS). Retrospective analysis.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
The document does not explicitly state the number and qualifications of experts involved in establishing ground truth for the pivotal study test set. It only mentions:
- For the Pilot Study: "Ground truth was determined by a review of a single radiologist and the radiology report. Another radiologist was used to break ties between the report and the reviewer." No specific qualifications for these radiologists are provided.
- For the Pivotal Study: The ground truth is implied to be established through expert review since it compares against "True Positive cases (i.e. identified as positive both by the reviewers as well as the BriefCase device)" in the time-saving study. However, details on the specific number and qualifications of these "reviewers" for the ground truth of the main 184 cases are missing.
4. Adjudication Method for the Test Set
- For the Pilot Study: A 2-expert method was used ("a review of a single radiologist and the radiology report. Another radiologist was used to break ties between the report and the reviewer.").
- For the Pivotal Study: The specific adjudication method for establishing ground truth for the 184 cases is not detailed.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No formal MRMC comparative effectiveness study that measures human reader improvement with and without AI assistance (i.e., effect size) was explicitly described.
However, a secondary endpoint in the pivotal study evaluated the "potential clinical benefit of worklist prioritization" by comparing the BriefCase time-to-notification to the standard of care time-to-exam-open. This indirectly assesses the impact on workflow triage.
- Effect Size (Proxy): The mean difference in time was **60.2 minutes (95% CI 32.7-87.6, p
§ 892.2080 Radiological computer aided triage and notification software.
(a)
Identification. Radiological computer aided triage and notification software is an image processing prescription device intended to aid in prioritization and triage of radiological medical images. The device notifies a designated list of clinicians of the availability of time sensitive radiological medical images for review based on computer aided image analysis of those images performed by the device. The device does not mark, highlight, or direct users' attention to a specific location in the original image. The device does not remove cases from a reading queue. The device operates in parallel with the standard of care, which remains the default option for all cases.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Design verification and validation must include:
(i) A detailed description of the notification and triage algorithms and all underlying image analysis algorithms including, but not limited to, a detailed description of the algorithm inputs and outputs, each major component or block, how the algorithm affects or relates to clinical practice or patient care, and any algorithm limitations.
(ii) A detailed description of pre-specified performance testing protocols and dataset(s) used to assess whether the device will provide effective triage (
e.g., improved time to review of prioritized images for pre-specified clinicians).(iii) Results from performance testing that demonstrate that the device will provide effective triage. The performance assessment must be based on an appropriate measure to estimate the clinical effectiveness. The test dataset must contain sufficient numbers of cases from important cohorts (
e.g., subsets defined by clinically relevant confounders, effect modifiers, associated diseases, and subsets defined by image acquisition characteristics) such that the performance estimates and confidence intervals for these individual subsets can be characterized with the device for the intended use population and imaging equipment.(iv) Stand-alone performance testing protocols and results of the device.
(v) Appropriate software documentation (
e.g., device hazard analysis; software requirements specification document; software design specification document; traceability analysis; description of verification and validation activities including system level test protocol, pass/fail criteria, and results).(2) Labeling must include the following:
(i) A detailed description of the patient population for which the device is indicated for use;
(ii) A detailed description of the intended user and user training that addresses appropriate use protocols for the device;
(iii) Discussion of warnings, precautions, and limitations must include situations in which the device may fail or may not operate at its expected performance level (
e.g., poor image quality for certain subpopulations), as applicable;(iv) A detailed description of compatible imaging hardware, imaging protocols, and requirements for input images;
(v) Device operating instructions; and
(vi) A detailed summary of the performance testing, including: test methods, dataset characteristics, triage effectiveness (
e.g., improved time to review of prioritized images for pre-specified clinicians), diagnostic accuracy of algorithms informing triage decision, and results with associated statistical uncertainty (e.g., confidence intervals), including a summary of subanalyses on case distributions stratified by relevant confounders, such as lesion and organ characteristics, disease stages, and imaging equipment.