(203 days)
The Faxitron VisionCT is a Cabinet x-ray system that is used to provide two and three dimensional digital x-ray images of harvested specimens from various anatomical regions in order to provide rapid verification that the correct tissue has been excised during the biopsy procedure. Doing the verification directly in the same room or nearby enables cases to be completed faster, thus limiting the time the patient needs to be under examination. Specimen radiography can potentially limit the number of patient recalls.
The Faxitron VisionCT is specially designed for high detail radiographic imaging of surgically excised medical specimens. It is a fully shielded Cabinet X- ray System that has been designed to comply with 21 CFR 1020.40. It allows up to 4.0 times geometric magnification of excised specimens with minimal geometric distortion through the use of a focal spot size that is less than 15 microns. With optimized cabinet geometry and the superior contrast available from the low kV capability. the VisionCT provides enhanced image performance. It is configured to acquire high resolution digital images up to 15 x 15 cm in size, through the use an integrated detector and Faxitron Vision Specimen Radiography software. The Faxitron Software supports the DICOM Store, Print and Modality Worklist services.
Here's an analysis of the provided text to extract information about the acceptance criteria and the study proving device performance:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state formal acceptance criteria in a quantitative table format for the device's diagnostic performance (e.g., sensitivity, specificity for detecting specific tissue types). Instead, it focuses on technical specifications and comparability to predicate devices. The "reported device performance" is primarily descriptive of its capabilities rather than a set of performance metrics against specific targets.
However, based on the non-clinical testing data mentioned, we can infer some "performance" aspects:
| Acceptance Criteria (Inferred/Implicit) | Reported Device Performance (from text) |
|---|---|
| Ability to provide 2D digital X-ray images of harvested specimens for rapid verification of excised tissue. | Demonstrated through sample clinical images of various anatomical regions (breast tissue, femoral head, other tissues such as fallopian tube, prostate, nasal polyp, and heart valve). |
| Ability to provide 3D digital X-ray images (CT Reconstruction). | Stated as a major difference and progression in technology from predicate devices. Sample clinical and phantom images provided. |
| Compliance with technical specifications. | All technical specifications (Focal spot size, kV, mA, power, beryllium window thickness, X-ray beam divergence, target material) are listed and implicitly met by the device. |
| Image quality for characterizing CT X-ray system contrast and detail imaging performance. | Data obtained from artifact analysis on sample clinical and phantom images with embedded test objects provided. |
| Compliance with electrical safety standards. | Successfully tested per IEC 61010-1, IEC 61010-2-091, and IEC 61010-2-101. |
| Compliance with electromagnetic compatibility standards. | Demonstrated through compliance with IEC 61326-1 and IEC 61326-2-6. |
| Compliance with cabinet X-ray system regulations. | Complies with 21 CFR 1020.40. |
| DICOM compliance. | Complies with NEMA PS 3.1 - 3.20 (DICOM). |
| Software functionality (GUI, 3D imaging support). | Faxitron Vision Software upgraded and thoroughly tested, including added capability for 3D X-ray images. |
2. Sample Size Used for the Test Set and Data Provenance
The document states: "The non-clinical performance testing data provided in this submission includes detector Xineos 1515 imaging performance data and sample clinical images to demonstrate the capability of the VisionCT to image various anatomical regions (breast tissue, femoral head, other tissues such as fallopian tube, prostate, nasal polyp, and heart valve)."
It also mentions: "The phantom images include those provided to compare the 2D images from the predicate device and 3D images from the subject device. In addition, a uniform phantom and phantom with embedded test objects with ranges of sizes and contrasts designed to characterize CT x-ray system contrast and detail imaging performance, are also provided."
- Test Set Sample Size:
- Clinical Images: The exact number of "sample clinical images" is not specified. It's described generally as "sample clinical images... to image various anatomical regions." This implies a limited set of images from different tissue types.
- Phantom Images: Not specified, but includes a "uniform phantom and phantom with embedded test objects."
- Data Provenance: Not specified in the provided text. It does not mention the country of origin or whether the data was retrospective or prospective for the clinical images. Given the context of a 510(k) summary, these are likely internal validation studies.
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 used or their qualifications for establishing ground truth on the "sample clinical images." The ground truth for these images would likely involve pathology or surgical confirmation of tissue excision, but this is not detailed.
4. Adjudication Method for the Test Set
The document does not describe any adjudication method (e.g., 2+1, 3+1, none) for a diagnostic interpretation of the test set. The focus is on the device's ability to provide images and its technical performance, not on a human interpretation study.
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
- No MRMC study was performed or described.
- The device is a specimen X-ray system providing 2D and 3D images for rapid verification of excised tissue during biopsy. It is not an AI-assisted diagnostic device, and therefore, no comparison of human readers with or without AI assistance is mentioned or relevant to this submission.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
- A standalone performance evaluation of the imaging system was done. The "non-clinical performance testing data provided" focuses on the device's technical specifications, imaging capabilities (2D and 3D), image quality using phantoms, and artifact analysis. This testing demonstrates the algorithm's (and hardware's) ability to produce images and reconstruct 3D data independently.
- However, it's crucial to distinguish this from an "algorithm only" performance for a diagnostic task. The device itself provides images; the human still performs the "verification that the correct tissue has been excised." The standalone performance here refers to the system's ability to generate high-quality images, not its ability to make a diagnostic call itself.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
- For the "sample clinical images," the implicit ground truth for verifying "correct tissue has been excised" would likely be pathology results or surgical confirmation that the specimen indeed represents the intended tissue. However, this is not explicitly stated.
- For the phantom images, the ground truth is the known characteristics of the phantom (e.g., sizes and contrasts of embedded test objects).
- For electrical safety and EMC, the ground truth is compliance with established international standards (IEC 61010 series, IEC 61326 series).
8. The Sample Size for the Training Set
The document does not mention a training set in the context of machine learning or AI. The Faxitron VisionCT is an imaging device, not an AI-based diagnostic algorithm that requires a separate training set. The "Faxitron Vision Software" mentioned is an operating software for the device, upgraded from a predicate, and was "thoroughly tested," but not in the sense of a machine learning training process.
9. How the Ground Truth for the Training Set Was Established
As no training set (for machine learning) is discussed, this question is not applicable.
§ 892.1680 Stationary x-ray system.
(a)
Identification. A stationary x-ray system is a permanently installed diagnostic system intended to generate and control x-rays for examination of various anatomical regions. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II (special controls). A radiographic contrast tray or radiology diagnostic kit intended for use with a stationary x-ray system only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.