(263 days)
The device is a permanently installed diagnostic x-ray system for general radiographic x-ray imaging including tomography. This device also supports dual energy chest imaging. The tomography and dual energy features are not to be used for imaging pediatric patients.
The modified Carestream DRX-Evolution/Plus is a stationary x-ray system with expanded capability to be used for Dual Energy adult chest radiographs. The only hardware change to the system to incorporate the Dual Energy functionality is a change to the existing collimator filter wheel. The previously cleared x-ray system contains a collimator filter wheel with multiple filters. For the Dual Energy Feature, a 0.5mm silver (Ag) filter was added to the 1mm aluminum (Al) filter location. This modified collimator filter wheel can be used for both general radiography and Dual Energy examinations.
The Dual Energy Feature is an imaging technique that takes advantage of the differential, energy-dependent absorption properties of bone and soft tissue structures in human anatomy. The operation consist of capturing two radiographic images of a patient in rapid succession, one at a relatively lower energy X-ray exposure compared to the second at a relatively higher energy exposure. These images are then subject to a weighted subtraction that can remove structures and produce three processed images, a Standard-of-Care image, a bone image, and a soft tissue image.
The Dual Energy Feature software includes a motion compensation option to suppress artifact due to involuntary patient motion that can occur between image acquisitions.
The DRX-Evolution/Plus system was cleared for use with tomography in a previous submission.
The Carestream Health, Inc. DRX-Evolution/Plus with Dual Energy device was evaluated through non-clinical (bench) testing and a clinical reader study to demonstrate its performance and safety.
Here's a breakdown of the requested information:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Overall image quality and radiation exposure (evaluated with chest phantom) | Non-clinical testing using an anthropomorphic chest phantom (simulating medium-to-small sized adults and larger patients with added PMMA plates) demonstrated that the phantom imaging exposure levels represent routine imaging conditions intended for clinical use. Although specific quantitative acceptance criteria are not provided for image quality metrics, the text states, "Test results demonstrated that the phantom imaging exposure levels represent the routine imaging conditions intended for clinical use." |
| Diagnostic image quality of Dual Energy software with and without patient motion artifact reduction (evaluated through clinical reader study) | Rating: "The Dual Energy Feature delivers quality imaging performance that is rated diagnostic (3) or better when processed with or without patient motion artifact reduction." (on a 4-point RadLex rating scale where 1 is non-diagnostic and 4 is exemplary). |
| Comparable image quality of low KV and high KV images to a standard/conventional PA chest radiograph | "Clinical data was provided in this submission to demonstrate that the low KV and high KV images are of comparable image quality to a standard/conventional PA chest radiograph." |
| Overall safety and effectiveness | "Bench testing and clinical study results have demonstrated that the DRX-Evolution/Plus system with Dual Energy software feature is safe and effective." |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: 120 Dual Energy studies.
- Data Provenance: Not explicitly stated, but the "clinical reader study" implies human patient data. It is not specified if the data was retrospective or prospective, nor the country of origin.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Number of Experts: Three (3).
- Qualifications of Experts: Board-certified radiologists. No specific years of experience are mentioned.
4. Adjudication Method for the Test Set
- Adjudication Method: Not explicitly detailed as a formal adjudication process. The radiologists evaluated images using a graduated 4-point RadLex rating scale. It's implied that individual ratings contributed to the overall finding that the imaging performance was diagnostic or better, but a method like 2+1 or 3+1 for resolving disagreements is not described.
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
- MRMC Study: No, a multi-reader multi-case (MRMC) comparative effectiveness study evaluating human readers with and without AI assistance was not explicitly described or performed. The clinical reader study focused on evaluating the diagnostic image quality of the Dual Energy software itself, with and without its own patient motion artifact reduction feature, rather than comparing human reader performance with and without AI assistance for diagnosis.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Standalone Performance: The study primarily evaluated the imaging performance of the Dual Energy software, including its ability to produce diagnostic quality images and its motion artifact reduction feature. While the software processes images without human intervention, the ultimate "diagnostic image quality" was assessed by human radiologists. Therefore, a purely standalone diagnostic performance without any human interpretation is not the focus of the reported study.
7. The Type of Ground Truth Used (Expert Consensus, Pathology, Outcomes Data, etc.)
- Type of Ground Truth: The ground truth for the clinical reader study was based on the expert opinion/ratings of three board-certified radiologists. They rated the "diagnostic image quality" on a 4-point RadLex scale. There is no mention of pathology, clinical outcomes, or other objective ground truth used to determine the accuracy of diagnoses made from these images.
8. The Sample Size for the Training Set
- Training Set Sample Size: Not provided. The document describes tests and a clinical reader study used for evaluation and validation, but it does not specify the size or nature of any dataset used to train the Dual Energy software's algorithms (e.g., for image processing or motion compensation).
9. How the Ground Truth for the Training Set Was Established
- Training Set Ground Truth Establishment: Not provided, as the training set details are not mentioned in the submission.
§ 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.