(260 days)
AcculCAS is software intended to be used for performing calculations in X-ray angiographic images of the intracranial vessels. AcculCAS enables neurointerventionalists to obtain quantifications of one or more lesions in the analyzed intracranial vessel segment. In particular, AccuICAS provides:
Quantitative results of intracranial vessel segments based on a 3D reconstructed model;
Dimensions of the intracranial vessels and lesions;
Quantification of the pressure gradient (PG) and pressure ratio (PR) in intracranial vessels.
AccuICAS is indicated for use in clinical settings where validated and reproducible quantified results are needed to support the assessment of intracranial vessels in X-ray angiographic images.
When the quantified results provided by AccuICAS are used in a clinical setting on X-ray images of an individual patient, the results are only intended for use by the responsible clinicians.
ArteryFlow AcculCAS is designed as a stand-alone software package to run on a PC. This software can read traditional x-ray angiographic images with DICOM format from the local file directory.
AcculCAS is composed of the following analysis workflows: Image Loading, Frame Selection, Vessel Reconstruction and Hemodynamics Calculation for visualization of the target intracranial vessel segment, quantification of morphological parameters and pressure drop of the intracranial vessel segment. AcculCAS is only for quantitative imaging output but not for diagnosis.
AcculCAS calculates the pressure gradient (PG) and pressure ratio (PR) value for the intracranial vessel. To obtain these values for a specific lesion in an intracranial vessel, the user needs to start with Frame Selection using the same vessel under different angulation. In each of these images, a classic 2D intracranial vessel contour detection is performed, after which a reconstruction of the intracranial vessel segment is obtained in 3D space. Based on the 3D reconstruction and patients' mean arterial pressure, the corresponding pressure gradient (PG) and pressure ratio (PR) value at each position can be calculated.
AcculCAS enables neurointerventionalists to obtain accurate anatomical quantifications of one or more lesions in the analyzed intracranial vessel segment, and to assess the best viewing angles which can be helpful for optimal visualization of the lesion.
AcculCAS's outputs mainly include quantitative dimension results of intracranial vessel and lesions segments based on a 3D reconstructed model and quantification of the pressure gradient (PG) and pressure ratio (PR) in intracranial vessels. Besides, other information provided to the end user also belongs to the outputs, such as display of reference vessels and lesions, display of target vessel lumen contour, 3D reconstructed model of intracranial vessels, the diameter stenosis distribution and PG/PR distributions.
Here's a breakdown of the acceptance criteria and study details for the AccuICAS device, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of acceptance criteria with numerical targets. Instead, it describes a qualitative acceptance: that "All of these tests met the predefined criteria, indicating that the AccuICAS algorithm is accurate, and the device is clinically acceptable." The performance is described by the successful validation of various outputs and calculations.
| Acceptance Criterion (Implied) | Reported Device Performance |
|---|---|
| Software Requirements Met | All requirements are tested, and all results of the tests performed are summarized in the software test report, providing traceability between requirements, design, and successfully executed tests. |
| Segmentation and Reconstruction Accuracy | Verified through the verification of the lumen and reference lumen contours and the verification of the 3D model. (Implies visual and/or quantitative assessment of accuracy, though specific metrics like Dice/IoU are not provided). |
| Morphological Parameters Accuracy | Verified using three brass phantoms and a dozen clinical data. (Implies the device's measurements for dimensions, etc., were accurate against known phantom values and clinical observations, though specific metrics like mean absolute error or agreement are not provided). |
| Diameter Stenosis & PG/PR Distributions Accuracy | Verified using data from several clinical patients with stenosis lesions. (Implies the calculated distributions aligned with clinical findings, though specific metrics for correlation or agreement are not provided). |
| Hemodynamics Calculation (PG/PR) Accuracy | Validated by comparing the calculated results with measured results. The comparison showed good correlation and agreement between the calculated and measured pressure gradients (PG) and pressure ratios (PR). (Implies high statistical correlation and agreement, though specific correlation coefficients, Bland-Altman agreement limits, or specific "measured results" are not detailed). The document also notes it was compared to "measured results," which implies a gold standard rather than expert consensus on images. |
| Overall Clinical Acceptability / Accuracy of Algorithm | All validation tests met the predefined criteria. |
| Safety and Effectiveness Equivalence to Predicate | AccuICAS is "as safe and effective as its predicate device." Differences do not raise new questions of safety and effectiveness. |
2. Sample Sizes Used for the Test Set and Data Provenance
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Sample Size:
- Morphological parameters: "three brass phantoms and a dozen clinical data." (A dozen typically means 12, so 15 total, 12 clinical data points).
- Diameter stenosis distribution, PG/PR distributions: "several clinical patients with stenosis lesions." (The exact number is not specified but is less precise than "a dozen").
- Hemodynamics calculation: "calculated results with the measured results." (Implies the testing involved a dataset that had both device-calculated and independently measured PG/PR values, but the sample size is not stated beyond "results").
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Data Provenance: The document does not explicitly state the country of origin for the clinical data or whether it was retrospective or prospective. Given the submitter's address (Hangzhou, CHINA), it is possible the clinical data originated from China, but this is not confirmed. The nature (retrospective/prospective) is also not specified.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
The document does not specify the number of experts used or their qualifications for establishing ground truth for the test set. The ground truth for hemodynamics validation seems to have come from "measured results" rather than expert consensus on images.
4. Adjudication Method for the Test Set
The document does not describe any adjudication method (e.g., 2+1, 3+1) for the test set. The validation seems to rely on comparisons against phantoms, "measured results," and unspecified clinical data outcomes.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done, What was the Effect Size of how much human readers improve with AI vs without AI assistance
No MRMC comparative effectiveness study involving human readers with and without AI assistance is mentioned or described in the provided text. The device is for "quantitative imaging output but not for diagnosis" and the validation focuses on the accuracy of its calculations.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was Done
Yes, the performance data presented appears to be a standalone (algorithm only) evaluation. The validation described tests the accuracy of the algorithm's outputs (segmentation, reconstruction, morphological parameters, hemodynamics calculations) against established references (phantoms, measured results), not against human interpretation assisted by the AI.
7. The Type of Ground Truth Used
- Phantoms: For morphological parameters (brass phantoms).
- "Measured Results": For hemodynamics calculations (PG and PR values). This suggests an independent, possibly invasive or highly accurate, method of obtaining these measurements, rather than clinical consensus readings from images.
- Clinical Data/Patient Observations: For diameter stenosis and PG/PR distributions, and implicitly for the "dozen clinical data" for morphological parameters. The exact nature of how this "ground truth" was established for clinical data is not specified (e.g., expert consensus, other imaging modalities, surgical findings, pathology reports, or long-term outcomes). However, the phrasing "compared the calculated results with the measured results" for PG/PR strongly implies an objective, independent measurement was the ground truth for that specific aspect.
8. The Sample Size for the Training Set
The document does not provide any information about the sample size used for the training set.
9. How the Ground Truth for the Training Set Was Established
The document does not provide any information about how the ground truth for the training set was established.
§ 892.1600 Angiographic x-ray system.
(a)
Identification. An angiographic x-ray system is a device intended for radiologic visualization of the heart, blood vessels, or lymphatic system during or after injection of a contrast medium. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.