(118 days)
This computed tomography system is intended to generate and process cross-sectional images by computed reconstruction of x-ray transmission data within a 26 cm field-of-view, for the head and neck.
The images delivered by the system can be used by a trained staff as an aid in diagnosis.
The SOMATOM On.site with software version syngo CT VB10 is a mobile computed tomography (CT) scanner system that will be offered in two variants:
- . SOMATOM On.site for Intensive Care Unit (ICU) Mobile CT scanner affixed to a motorized trolley for use in hospital situations. The scanner can be moved from patient bed to patient bed to perform scanning at the point of care. Although it might be used in other environments like emergency rooms or angiography labs, the main location where this scanner will be used, will be the intensive care unit (ICU).
- . SOMATOM On.site for Mobile Stroke Unit (MSU) Mobile CT Scanner that is mounted to the floor of a diagnostic room or vehicle. The system main place where the scanner will be mounted is in a mobile stroke unit (MSU), which is a specific type of ambulance.
The subject device SOMATOM On.site with SOMARIS/10 syngo CT VB10 is a mobile Computed Tomography X-ray Systems which features a continuously rotating tube-detector system and function according to the fan beam principle. The SOMATOM On.site with software SOMARIS/10 syngo CT VB10 produces CT images in DICOM format, which can be used by trained staff for postprocessing applications commercially distributed by Siemens Healthcare and other vendors as an aid in diagnosis and treatment preparation. The computer system integrated with the CT scanner is able to run optional post processing applications.
The Siemens SOMATOM On.site (SOMARIS/10 syngo CT VB10) is a computed tomography (CT) X-ray system. The provided text describes the non-clinical testing performed to demonstrate the device's performance and substantial equivalence to predicate devices. The study focuses on evaluating specific upgraded software features (FAST kV, CARE Dose4D, X-CARE, ADMIRE).
Here's an analysis of the acceptance criteria and study details:
1. Table of Acceptance Criteria and Reported Device Performance
| Feature/Metric | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| FAST kV | Image Quality (Contrast-to-Noise Ratio): CNR values at 80 kV and 120 kV should be consistent (deviations well below 15%). | |
| Radiation Dose Reduction: Dose levels should be reduced at 80 kV, especially for the 'vascular' setting. | For iodine and calcium contrast material inserts in a cylindrical 20 cm water phantom, CNR values at 80 kV and 120 kV are consistent (deviations well below 15%). | |
| Dose levels at 80 kV are slightly reduced (-5%) with the 'bone/calcium' setting and substantially reduced (-44%) with the 'vascular' setting compared to 120 kV. | ||
| CARE Dose4D | Comparable performance of CARE Dose4D in SOMATOM On.site to the predicate device SOMATOM go.Up. | |
| CARE Dose4D should lead to reduced dose levels at consistent image quality. | Evaluation showed equivalent performance results for CARE Dose4D in the subject device SOMATOM On.site and the predicate device SOMATOM go.Up with respect to radiation dose (CTDIvol) and image noise levels. Clinical publications (not detailed here) already demonstrate dose reduction potential of CARE Dose4D. | |
| X-CARE | Comparable performance of X-CARE in SOMATOM On.site to the predicate device SOMATOM go.Up. | |
| X-CARE should lead to reduced dose levels to the eye lenses at consistent image quality. | Evaluation showed equivalent performance results for X-CARE in the subject device SOMATOM On.site and the predicate device SOMATOM go.Up with respect to radiation dose (CTDIvol) and image noise levels. Clinical publications (not detailed here) already demonstrate organ dose reduction potential of X-CARE. | |
| ADMIRE | Reduces image noise without noticeable loss of sharpness. | |
| Mean CT values, including water value, should not vary when ADMIRE is used instead of a weighted filtered back-projection (WFBP). | Water value and CT value of PTFE object remain constant with increasing ADMIRE strength settings and compared to WFBP. | |
| Sharpness, demonstrated with edge MTF, is constant with increasing ADMIRE strength setting and WFBP. | ||
| Image noise decreases compared to WFBP and with increasing ADMIRE strength, while maintaining a Gaussian noise distribution for a natural image impression. |
2. Sample Size for the Test Set and Data Provenance
The document describes phantom-based measurements for the non-clinical testing. Specific numerical sample sizes (e.g., number of scans, number of phantoms) are not explicitly provided beyond mentioning "a cylindrical 20 cm water phantom" and "PTFE object" for ADMIRE. The data provenance is not explicitly stated as retrospective or prospective, but given it's "bench testing" performed "during product development," it implies a prospective non-clinical study design. The "country of origin of the data" is not specified but is likely internal to Siemens Healthineers.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
For non-clinical phantom studies, the concept of "experts establishing ground truth" as it would apply to clinical image interpretation is not directly applicable. The "ground truth" for these tests is established by:
- Physical properties of the phantoms: The known composition and dimensions of the water and PTFE phantoms.
- Established quantitative image quality metrics: Such as CNR, MTF, and noise measurements, which are objectively calculated by the system or analysis software based on internationally recognized standards.
- Comparison to predicate device performance: For CARE Dose4D and X-CARE, performance is compared to the established and cleared predicate device, SOMATOM go.Up.
Therefore, no external clinical experts are mentioned for establishing ground truth in these specific non-clinical tests.
4. Adjudication Method for the Test Set
Not applicable for non-clinical phantom studies based on objective quantitative measurements. The assessment is based on direct measurement results against pre-defined acceptance criteria.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. The provided text describes non-clinical bench testing using phantoms, not clinical studies involving human readers or cases. Therefore, no MRMC study was performed, and no effect size for human reader improvement with/without AI assistance is reported.
6. Standalone Performance Study
Yes, the studies reported are standalone (algorithm only) performance evaluations of specific software features (FAST kV, CARE Dose4D, X-CARE, ADMIRE) on the SOMATOM On.site CT scanner, using phantoms. This is a non-human-in-the-loop assessment of the technical performance of the algorithms and hardware.
7. Type of Ground Truth Used
The ground truth used is primarily based on:
- Known physical properties of phantoms: e.g., known dimensions, material composition (water, PTFE), and contrast agent concentrations.
- Objective quantitative measurements: Metrics like Contrast-to-Noise Ratio (CNR), Modulation Transfer Function (MTF) for sharpness, and noise levels.
- Performance of a predicate device: For CARE Dose4D and X-CARE, the performance of the predicate device (SOMATOM go.Up) serves as a benchmark for "comparable performance."
8. Sample Size for the Training Set
The document does not specify a separate "training set" or its size. The features being evaluated (FAST kV, CARE Dose4D, X-CARE, ADMIRE) are algorithmic components of the CT system. While these algorithms might have been developed using various data, the document focuses on the validation testing of their performance on the new device, not their initial development or training. It states that ADMIRE was "originally approved with K133646," indicating it's an existing algorithm that has been integrated.
9. How the Ground Truth for the Training Set Was Established
As no training set is explicitly mentioned or detailed in this document, the method for establishing its ground truth is also not provided. The focus is on the verification and validation of the integrated system.
§ 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.