(232 days)
bright CT is a computed tomography x-ray system intended to produce 3D, panoramic, and cephalometric diagnostic images of the maxillofacial areas for treatment planning for adult and pediatic patients. The device is operated and used by physicians, dentists, and x-ray technicians.
Rainbow 3D Image Viewer software functions for acquiring, saving, searching, displaying, diagnosing and sending digital X-ray image data in dental practices and clinics.
bright CT is a cone beam CT X-ray device for generating sectional images of dental images such as tooth, nasal cavity and temporomandibular joint. this is a medical diagnostic equipment designed to generate sectional images by placing X-ray source opposite to the imaging detector unit and rotating it around a patient. 2D images of the region of interest are reconstructed using a mathematical algorithm in 3 dimensional volumetric view and displayed on the computer monitor.
The system is composed of X-ray generator, X-ray detector, X-ray collimator, main frame, rotation unit, PC and Monitor, etc. in compliance with US performance standard and regulatory requirement.
Here's an analysis of the acceptance criteria and the study proving the "bright CT" device meets those criteria, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state formal "acceptance criteria" for the performance characteristics in the way one might typically see for a medical device (e.g., "The MTF for CBCT must be greater than X%"). Instead, the performance claims for the "bright CT" are evaluated against those of a predicate device, the "rainbow CT." The key criteria for substantial equivalence appear to be matching or improving upon the predicate's performance.
| Parameter | Acceptance Criteria (Predicate Device rainbow CT) | Reported Device Performance (bright CT) | Comment |
|---|---|---|---|
| CBCT Image Performance | |||
| MTF@ 1 lp/mm | 53% (C12820DK-40) | 54% (DTX1512), 53% (DTX1524) | Meets/Exceeds: The DTX1512 sensor in bright CT exceeds the predicate, while the DTX1524 matches. The document states "performed similar to or better than." |
| DQE @ 0.5 lp/mm | 85% (C12820DK-40) | 88% (DTX1512), 85% (DTX1524) | Meets/Exceeds: The DTX1512 sensor in bright CT exceeds the predicate, while the DTX1524 matches. The document states "performed similar to or better than." |
| Pixel Resolution | 2 lp/mm – 2x2 binning (C12820DK-40) | 2 lp/mm – 1-4 subsampling | Meets/Exceeds: The "1-4 subsampling" terminology for bright CT is slightly different from "2x2 binning" for the predicate, but the resolution of 2 lp/mm is maintained. The document states "similar or superior." |
| Pixel Size | 240 μm (2x2 binning) (C12820DK-40) | 200 μm (2x2 binning) | Exceeds: Smaller pixel size for bright CT (200 μm) compared to predicate (240 μm) indicates better resolution if other factors are equal. The document states "similar or superior to that of the reference device." |
| FOV | 5x5, 16x10, 16x18 cm | 5x5, 12x9.5, 17.5x9.5, 10x9.5, 5x9.5, 17.5x15 cm | Different: The FOV options are different. This is noted as a difference but deemed not to raise new questions about safety and effectiveness, implying the new FOVs are acceptable for the intended use. |
| Panoramic Image Performance | |||
| MTF@ 1 lp/mm | 53% (DTX1524), 53% (C12820DK-40) | 54% (DTX1512), 53% (DTX1524) | Meets/Exceeds: The DTX1512 sensor in bright CT exceeds the predicate, while the DTX1524 matches. |
| DQE @ 0.5 lp/mm | 85% (DTX1524), 85% (C12820DK-40) | 88% (DTX1512), 85% (DTX1524) | Meets/Exceeds: The DTX1512 sensor in bright CT exceeds the predicate, while the DTX1524 matches. |
| Pixel Resolution | 4 lp/mm | 4 lp/mm – 1x1 | Meets: Matches the predicate. The document states "similar or superior." |
| Pixel Size | 120 μm (C12820DK-40) | 100 μm | Exceeds: Smaller pixel size (100 μm) compared to predicate (120 μm) indicates better resolution if other factors are equal. The document states "similar or superior to that of the reference device." |
| Cephalometric Image Performance | |||
| MTF@ 1 lp/mm | 56% (C10502D-43) | 53% (DTX2906) | Does not meet: The bright CT's DTX2906 sensor has a lower MTF (53%) than the predicate's C10502D-43 (56%). The document broadly states "performed similar to or better than" regarding MTF, DQE, and pixel resolution for the subject device compared to the predicate, but this specific metric appears to be lower. However, the overall conclusion is still substantial equivalence, suggesting this difference was not considered clinically significant. |
| DQE @ 0.5 lp/mm | 60% (C10502D-43) | 80% (DTX2906) | Exceeds: Higher DQE (80%) compared to predicate (60%), indicating better image quality at lower doses. The document states "performed similar to or better than." |
| Pixel Resolution | 4.5 lp/mm | 4.5 lp/mm – 1x1 | Meets: Matches the predicate. The document states "similar or superior." |
| Pixel Size | 100 μm | 100 μm | Meets: Matches the predicate. |
| General Device Characteristics | |||
| Indications for Use | Same as bright CT (K200271) | Same as predicate | Meets: Identical indications for use. |
| Imaging Software | Rainbow 3D ImageViewer | Rainbow 3D ImageViewer | Meets: Identical software. |
| Tube Voltage | 60~100 kV | 60~100kV | Meets: Identical range. |
| Tube Current | 4~12 mA | 4~12 mA | Meets: Identical range. |
| Focal Spot Size | 0.5 mm | 0.5 mm | Meets: Identical. |
| Total Filtration | 2.8 mm Al | 3 mm Al | Different: Slightly higher filtration for bright CT. This is a difference but not identified as a safety or effectiveness concern, likely due to common practices in X-ray systems. |
| Exposure Time | Max. 19 s | Max. 20 s (For Stitching: Max. 40S) | Different: Longer maximum exposure time for bright CT, especially for stitching. This difference is accepted. |
| Software | DICOM 3.0 compatible | DICOM 3.0 Format compatible | Meets: Identical compatibility. |
| Anatomical Sites | Maxillofacial | Maxillofacial | Meets: Identical. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not specify a "test set" in terms of patient images or specific clinical cases. The performance evaluation appears to be based on non-clinical data and performance testing directly on the device's physical components and imaging capabilities.
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Sample Size for performance tests: Not explicitly stated for each test (e.g., how many measurements for MTF/DQE).
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Data Provenance: The document does not describe the use of patient data for performance evaluation in a testing context. The testing instead involved established international and national standards:
- IEC 60601-1 (Electrical, mechanical, environmental safety)
- IEC 60601-1-3 (Radiation protection)
- IEC 60601-1-6 (Usability)
- IEC 60601-2-63 (Specific requirements for dental x-ray equipment)
- IEC 60601-1-2 (EMC)
- NEMA PS 3.1-3.18 (DICOM)
- FDA Guidance "Guidance for the submissions of 510(k)'s for Solid State X-ray Imaging Devices"
- IEC 61223-3-4 & IEC 61223-3-5 (Acceptance tests for diagnostic X-ray imaging equipment)
These tests typically involve physical phantoms and measurement equipment, not clinical patient data. Therefore, questions regarding country of origin or retrospective/prospective nature of data are not applicable to the described performance testing.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Experts
Not applicable. As noted above, the primary performance evaluation was based on non-clinical, objective measurements of the device's technical specifications against regulatory standards and comparison to a predicate device, not on expert interpretation of clinical images for ground truth.
4. Adjudication Method for the Test Set
Not applicable, as there was no test set requiring expert adjudication.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, and the effect size of how much human readers improve with AI vs without AI assistance
No MRMC comparative effectiveness study was done. The device, "bright CT," is a CT X-ray system for acquiring images, not an AI-powered diagnostic aide. Therefore, the concept of human readers improving with AI assistance is not relevant to this submission.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. The device is a hardware imaging system. There is no standalone algorithm being evaluated for diagnostic performance.
7. The Type of Ground Truth Used
The "ground truth" for evaluating the technical performance claims (MTF, DQE, pixel resolution, etc.) was established through objective physical measurements using standardized phantoms and measurement techniques as prescribed by the mentioned IEC and NEMA standards. For the safety and efficacy evaluation of the overall device, the ground truth was substantial equivalence to a legally marketed predicate device (rainbow CT), demonstrating that the differences do not raise new questions of safety or effectiveness.
8. The Sample Size for the Training Set
Not applicable. This device is an imaging acquisition system, not a machine learning algorithm that requires a training set of data.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set mentioned or implied for this device.
§ 892.1750 Computed tomography x-ray system.
(a)
Identification. A computed tomography x-ray system is a diagnostic x-ray system intended to produce cross-sectional images of the body by computer reconstruction of x-ray transmission data from the same axial plane taken at different angles. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.