(99 days)
The CXR16 Computed Tomography system is an x-ray imaging device that produces cross-sectional images of the body at different angles. The system reconstructs, processes, displays, and stores the collected images. The device output can provide an aid to diagnosis when used by a qualified physician.
The CXR16 is a multi-slice computed tomography system that uses x-ray data to produce cross-sectional images of the body at various angles. The CXR16 system uses "third generation" CT technology, where the x-ray tube and detector assemblies are mounted on a frame that rotates continuously around the patient using slip ring technology. The solid-state detector assembly design collects up to 16 slices of data simultaneously. The x-ray sub-system features a high frequency generator, x-ray tube, and collimation system that produces a fan beam x-ray output. The system can operate in a helical (spiral) scan mode where the patient table moves during scanning. As the x-ray tube/detector assembly rotates around the patient, data is collected at multiple angles. The collected data is then reconstructed into cross-sectional images by a high-speed reconstruction sub-system. The images are displayed on a computer workstation, stored, printed, and archived as required. The workstation is based on current PC technology using the Windows™ operating system. The CXR16 system consisting of a gantry, operator's workstation, patient table, high-frequency x-ray generator, and accessories.
The provided text describes a 510(k) summary for the Hitachi CXR16 Computed Tomography X-ray System. This document focuses on demonstrating substantial equivalence to a predicate device, rather than providing detailed acceptance criteria and a study report as would be found for a novel device or AI/ML algorithm.
Therefore, many of the requested details about acceptance criteria, sample sizes, expert ground truth, and comparative effectiveness studies are not available in this specific document because the regulatory pathway for this type of device (a CT scanner) typically focuses on demonstrating that the new device performs similarly to an existing, legally marketed device through non-clinical evaluations rather than clinical trials with extensive reader studies.
Here's an analysis based on the provided text, indicating which information is present and which is not:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Stipulated in 21 CFR 1020.33(c)) | Reported Device Performance (CXR16) |
|---|---|
| Dose Profile | Comparable to predicate device |
| Image Noise | Comparable to predicate device |
| Modulation Transfer Function (MTF) | Comparable to predicate device |
| Slice Thickness and Sensitivity Profile | Comparable to predicate device |
| Slice Plane Location | Comparable to predicate device |
| CT Dose Index | Comparable to predicate device |
Explanation: The document states, "Because the CXR16 and the predicate device are both Hitachi designs, they were subjected to the same non-clinical evaluations as stipulated in 21 CFR 1020.33(c). Evaluations include: dose profile, image noise, modulation transfer function (MTF), slice thickness and sensitivity profile, slice plane location, and CT dose index. The evaluation results of the CXR16 were comparable to the predicate device and support our conclusion that the CXR16 CT system is substantially equivalent."
2. Sample size used for the test set and the data provenance
- Sample Size: Not specified. This would typically involve physical measurements and phantom studies, not a "test set" of patient data in the way an AI/ML algorithm would use.
- Data Provenance: Not applicable in the context of the described non-clinical evaluations. These are technical evaluations of the scanner's performance characteristics.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Not applicable. Ground truth for these physical performance metrics is established through standardized measurement methods using phantoms and test equipment, not human experts.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable. Adjudication methods are relevant for human interpretation of data, typically in diagnostic performance studies. The evaluations described are objective, quantitative technical measurements of the CT system's physical performance characteristics.
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. This is a traditional CT scanner, not an AI-assisted diagnostic tool. Therefore, no MRMC study or AI-related effectiveness study was performed or is relevant to this submission.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not applicable. This is a hardware medical device (CT scanner), not a standalone software algorithm. Its "performance" is its ability to acquire and reconstruct images with specific technical specifications.
7. The type of ground truth used
- Physical Measurements/Standards: The "ground truth" for the non-clinical evaluations (e.g., dose profile, image noise, MTF) would be derived from precisely calibrated equipment, phantoms, and standardized measurement techniques against established industry or regulatory standards for CT performance.
8. The sample size for the training set
- Not applicable. This is a hardware device; it does not have a "training set" in the context of AI/ML or image interpretation. The device itself is designed and built based on engineering principles and validated through physical testing.
9. How the ground truth for the training set was established
- Not applicable. As a hardware device, there is no "training set" for which ground truth would be established. The design and manufacturing processes are validated through engineering and quality control measures.
Summary of Device Performance Demonstration:
The Hitachi CXR16 demonstrates its performance by showing comparability to its predicate device (Hitachi Presto CT, K040902) across several non-clinical evaluation parameters stipulated in 21 CFR 1020.33(c). The key differences highlighted are the ability to acquire 16 slices simultaneously, reducing scan time, and "improvements in overall technology." The manufacturer asserts that these differences do not change the essential characteristics or safety/effectiveness compared to the predicate device, leading to a conclusion of substantial equivalence.
§ 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.