(91 days)
The Optima CT660 is intended to produce cross-sectional images of the body by computer reconstruction of x-ray transmission data taken at different angles and planes, including Axial, Cine, Helical (Volumetric), Cardiac, and Gated acquisitions. These images may be obtained either with or without contrast. This device may include signal analysis and display equipment, patient and equipment supports, components and accessories.
This device may include data and image processing to produce images in a variety of transaxial and reformatted planes. Further the images can be post processed to produce additional imaging planes or analysis results.
The system is indicated for head, whole body, cardiac and vascular X-ray Computed Tomography applications in patients of all ages.
The device output is a valuable medical tool for the diagnosis of disease, trauma, or abnormality and for planning, guiding, and monitoring therapy.
The Optima CT660 v2 CT system is composed of a gantry, patient table, operator console, computer, power distribution unit (PDU), and interconnecting cables. The system includes image acquisition hardware, image acquisition, reconstruction software, associated accessories, and connections/interfaces to accessories.
The current system configuration/package names are: Optima CT660, Optima CT660 Pro, Optima CT660 s, Optima CT660 sPro, Optima CT660SE, Optima CT660 FREEdom.
The system generates images through the computer reconstruction of data acquired at different angles and planes of the rotating gantry. The gantry can rotate at up to 0.35 seconds per rotation, and can acquire up to 64 slices/rows of data per rotation with a maximum total collimation coverage of 40mm in the z direction. The system can be operated in Axial, Cine, Helical, Cardiac and Gated acquisition modes.
The system is designed as an evolutionary modification to the Optima CT660 CT Scanner System (K110227). Most of hardware is identical to the predicate system, however some has undergone changes due to the need to meet IEC60601-1 Ed. 3 and RoHS regulation and also for reducing costs while maintaining performance, compliance, and specifications. The software has been updated in accordance with GE's quality management system procedures that incorporate the software development life cycle to introduce the new features discussed in this submittal. Software updates were also made for quality (bug) fixes and to meet the new requirements of IEC 60601-2-44 Ed. 3.0.
The Optima CT660 v2 uses virtually the same materials and identical operating principle as our existing marketed product, except in the case of using the compensatory ROHS compliant materials. The image chain components (tube, collimator, detector, DAS) are virtually identical to the predicate device.
The changes do not affect the intended use, the indications for use, patient population nor fundamental operating principles of the currently commercially available predicate system and are the identical or similar to other GE CT systems and features previously cleared.
The Optima CT660 v2 CT system is intended to be a head and whole body CT system incorporating the same basic fundamental operating principles and the same indications for use as the predicate device. Materials and construction are equivalent to our existing marketed products which are compliant with ES 60601-1. IEC 60601-1 and associated collateral and particular standards, 21 CFR Subchapter J, and NEMA XR-25. The accompanying documents also contain the information in support if IEC61223-3-5 and IEC61223-2-6 for acceptance and constancy testing. All changes have been tested and certified by a NRTL and continue to meet all applicable IEC/UL safety standards.
The modified system has been developed under the same GE quality system and has completed all design controls, including risk management, verification and validation.
Here's a breakdown of the acceptance criteria and study information for the Optima CT660 v2, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Feature | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Organ Dose Modulation (ODM) | Maintain diagnostic image quality while reducing radiation dose in superficial tissues. | "Tests on phantoms confirmed that ODM enables reducing radiation dose in the superficial tissues while maintaining diagnostic image quality." |
| Maintain equivalent mean CT number accuracy and uniformity. | "Tests were also conducted on phantoms that confirmed the ODM enables equivalent mean CT number accuracy and uniformity." | |
| Ultra Kernel (UK) | Improve visual spatial resolution. | "Phantoms were used to test and demonstrate that Ultra kernel improves visual spatial resolution..." |
| Maintain pixel noise standard deviation. | "...while maintaining pixel noise standard deviation..." | |
| Maintain level of image artifacts. | "...and level of image artifacts." | |
| High Pitch Helical (HPH) | Meet GE's existing helical image quality specifications. | "Performance tests on phantoms were conducted and demonstrated that the helical pitch 1.531 meets GE's image quality specifications for lower pitch acquisitions." |
| Overall Device (with new features) | Perform as intended and in a substantially equivalent manner to the unmodified predicate device, with diagnostic results obtained. | "The image quality assessment on the sample clinical CT exam images... demonstrated that diagnostic results (and actual diagnoses) were obtained for all 47 subject exams." |
| Not introduce new potential safety risks. | "The Optima CT660 v2 does not raise any new potential safety risks..." | |
| Perform as well as devices currently on the market. | "...and performs as well as devices currently on the market." |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: 47 subject clinical exams.
- Data Provenance: The document does not explicitly state the country of origin or if the data was retrospective or prospective. It mentions "sample clinical exams were collected and reviewed," suggesting these were existing exams.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Number of Experts: Two independent radiologists.
- Qualifications of Experts: The document states "two independent radiologists" but does not provide specific details on their years of experience or subspecialties.
4. Adjudication Method for the Test Set
- There is no explicit mention of an adjudication method (e.g., 2+1, 3+1). The assessment was performed by "two independent radiologists" using a 5-point Likert scale. It's unclear how disagreements, if any, were resolved.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done in the context of human readers improving with AI vs. without AI assistance. The study described is an assessment of image quality by human readers on images generated by the new features of the CT system. The device features are designed to improve image acquisition and reconstruction, not to directly assist human readers in their interpretation (e.g., by providing CAD).
6. If a Standalone Study Was Done (Algorithm Only Without Human-in-the-Loop Performance)
- Yes, standalone performance was tested extensively using phantoms for the new features (ODM, Ultra Kernel, HPH). These tests assessed the technical performance of the algorithms in terms of dose reduction, spatial resolution, noise, artifacts, and image quality specifications.
7. The Type of Ground Truth Used
- For the phantom tests, the ground truth would be the known physical properties and measurements within the phantoms (e.g., known dose values, resolution patterns, CT number accuracies).
- For the clinical image assessment, the ground truth was "diagnostic quality" as assessed by two independent radiologists, leading to "diagnostic results (and actual diagnoses)." This is a form of expert consensus/reader assessment.
8. The Sample Size for the Training Set
- The document does not report a specific sample size for a training set. This device is an evolutionary modification to an existing CT system, and the new features (ODM, UK, HPH) are primarily related to image acquisition and reconstruction algorithms, which might not be "trained" in the same way a deep learning AI model is. The development heavily relied on engineering verification and validation.
9. How the Ground Truth for the Training Set Was Established
- As a training set is not explicitly mentioned or quantified, how its ground truth was established is not provided in the document. The development processes involve adherence to standards, risk analysis, design reviews, and various levels of testing (module, integration, performance, safety, simulated use), which collectively ensure the device's technical performance and safety, rather than relying on a labeled training dataset for an AI model.
§ 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.