(92 days)
The NLS128 [NExCT 7] system is intended to be used for x-ray computed tomography applications that produce cross sectional images for anatomy that can be imaged in the system aperture. The NExCT 7 is intended to be used for both pediatric and adult imaging and as such has preset dose settings based upon weight and age.
The NExCT 7 system is essentially a higher slice, higher speed, stationary version of our predicate NL4000 BodyTom CT system. It has comparable detector coverage (80 mm), speed (0.25s) and features as the Toshiba Aquilion ONE Vision. It is a high resolution, 128 row, 78 cm aperture, 50cm field of view, Computed Tomography System. The stationary gantry consists of a rotating disk with a solid state x-ray generator, solid state detector array, collimator, control computer, communications link, power slip-ring, data acquisition system, reconstruction computer, power system, brushless DC servo drive system (disk rotation), and patient table with stepper drive translation system. The Power Distribution Unit is a UL listed device. The display/control console consists of a commercial off the shelf (COTS) computer and monitor. The system control software is a modification to the BodyTom software. The system has the necessary safety features such as emergency stop switch, x-ray indicators, interlocks, patient alignment laser, and 110 percent x-ray timer. In addition the system complies with the Medical Imaging Technology Alliance (MITA) Smart Dose standard to optimize and manage radiation dose delivery. This includes radiation protection measures such as the MITA Dose Check Standard and the MITA Access Control Standard.
This 510(k) summary does not contain the detailed information necessary to fully answer all parts of your request regarding acceptance criteria and performance studies. The document focuses on establishing substantial equivalence to predicate devices based on design, materials, functionality, and technology, rather than presenting a comprehensive clinical or standalone performance study of the NExCT 7.
Here's what can be extracted and what cannot:
1. A table of acceptance criteria and the reported device performance
The document mentions that "Image quality metrics such as noise, slice thickness, low and high contrast resolution, radiation metrics, and modulation transfer function were measured utilizing phantom image quality tests in accordance with the equipment performance standards for diagnostic x-ray systems administered by the FDA."
However, it does not provide specific numerical acceptance criteria for these metrics nor the reported performance values for the NExCT 7. It only states that these tests were conducted and that the system "performs as well in its intended use as devices currently on the market."
| Acceptance Criteria (e.g., max noise, min resolution) | Reported Device Performance |
|---|---|
| Not specified in the document | Not specified in the document |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document refers to "phantom image quality tests." This implies that the test set consisted of phantoms, not human patient data. Therefore, questions about country of origin and retrospective/prospective data are not applicable. The sample size for the test set (number of phantoms or scans performed) is not specified.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
For phantom studies, ground truth is typically established by physical measurements and the known properties of the phantom, not by expert human readers. Therefore, the number and qualifications of experts for ground truth establishment are not applicable to this type of study as described.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Since ghost data, the adjudication method is not applicable.
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
The document does not mention any MRMC comparative effectiveness study involving human readers or AI assistance. The study described is a technical phantom study to evaluate image quality. Therefore, this information is not provided.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
The document describes "phantom image quality tests" which suggests a standalone technical performance evaluation of the CT system itself (the NExCT 7). These tests are typically conducted without human interpretation as part of the primary measurement, focusing on intrinsic image quality metrics. However, it's not an "algorithm" in the sense of an AI algorithm, but rather the imaging system's performance. So, a standalone technical performance study was done for the imaging device, but not specifically for a separate AI algorithm within it.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
For the phantom studies, the ground truth would be based on the objective physical properties and known characteristics of the phantoms used for image quality assessment (e.g., a phantom designed to have a certain density, or containing objects of known size and contrast).
8. The sample size for the training set
This document describes a CT system (hardware). It is not an AI software algorithm that typically requires a "training set." Therefore, the concept of a training set sample size is not applicable.
9. How the ground truth for the training set was established
As there is no training set mentioned for this hardware device, this question is not applicable.
In summary:
This 510(k) summary primarily addresses the substantial equivalence of a new CT imaging system (NExCT 7) to existing predicate devices based on technical specifications and phantom image quality tests. It does not delve into clinical performance studies with human subjects, AI performance, or detailed acceptance criteria with specific numerical performance metrics. The evidence presented focuses on demonstrating that the device meets general safety standards and produces image quality comparable to predicate devices through technical evaluations.
§ 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.