(276 days)
The Siemens SOMATOM Definition AS Open systems are intended to produce cross-sectional images of the body by computer reconstruction of x-ray transmission data from either the same axial plane taken at different angles or spiral planes* taken at different angles.
(*spiral planes: the axial planes resulted from the continuous rotation of detectors and x-ray tube, and the simultaneous translation of the patient.)
The Siemens SOMATOM Definition AS Open is a whole body X-ray Computed Tomography System. The SOMATOM Definition AS Open produces CT images in DICOM format, which can be used by post-processing applications commercially distributed by Siemens and other vendors.
The system software is a command-based program used for patient management, data management, X-ray scan control, image reconstruction, and image archive/evaluation. The new version of system software, syngo® CT 2013B (SOMARIS/7 VA46A), supports the following features:
- MARIS (Metal Artifact Reduction in Image Space) A image . reconstruction mode designed to reduce image artifacts caused by metal
- HD FoV Pro (HD FoV 2.0) Designed to enable a more reliable . visualization of the skin line of human body parts located outside of the standard field of view
- t-MIP -- Image manipulation method for arithmetic operations which allows . the calculation of temporal Maximum or Minimum Intensity Projection (MIP) images from a set of series.
Here's a breakdown of the acceptance criteria and the study information for the SOMATOM Definition AS Open configured with software version syngo® CT 2013B (SOMARIS/7 VA46A), based on the provided text:
Important Note: The provided document is a 510(k) summary for a medical device which is largely about demonstrating "substantial equivalence" to a predicate device. This type of submission often focuses on verifying that new features don't introduce new safety or effectiveness concerns, rather than conducting a full-scale clinical trial to prove a specific level of diagnostic performance against a robust ground truth. As such, some of the requested information (especially about specific performance metrics tied to acceptance criteria, MRMC studies, and detailed ground truth establishment for clinical effect) might not be explicitly present or as detailed as in a typical in vitro diagnostic (IVD) or AI-only software submission.
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria / Feature | Reported Device Performance (as described in the document) |
|---|---|
| MARIS (Metal Artifact Reduction in Image Space) Effectiveness | Validated through clinical tests in different clinical scenarios. Designed to reduce image artifacts caused by metal. |
| HD FoV Pro (HD FoV 2.0) Visualization Range | Designed to enable a more reliable visualization of the skin line of human body parts located outside of the standard field of view. Allows visualization of up to 80 cm. |
| t-MIP (Temporal Maximum or Minimum Intensity Projection) Capability | Allows the calculation of temporal Maximum or Minimum Intensity Projection (MIP) images from a set of series. |
| Software Specifications | All software specifications have met the acceptance criteria (general statement from risk analysis and V&V). |
| Substantial Equivalence (General) | No new potential safety risks; performs as well as the predicate devices. |
| Conformance to Standards (e.g., IEC 60601-1-4, IEC 62304, ISO 14971, DICOM, IEC 60601-2-44, IEC 61223-3-5, IEC 61223-2-6) | Designed to fulfill the requirements of these standards. Performance data demonstrates continued conformance with special controls for medical devices containing software. |
| EMC/Electrical Safety | Evaluated according to IEC Standards; Siemens certifies conformance to Voluntary Standards covering Electrical and Mechanical Safety. |
| Risk Mitigation | Risk analysis completed and risk control implemented to mitigate identified hazards. |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size (Clinical Tests): Not specified. The document states "Clinical tests were performed... to validate the performance of the MARIS algorithm" and "These tests include testing of the metal artifact reduction capabilities of MARIS in different clinical scenarios." However, the number of patients, scans, or images is not provided.
- Data Provenance: Not explicitly stated (e.g., country of origin). The tests were "clinical tests," implying real patient data. It is highly likely to be retrospective clinical data, as typical for 510(k) submissions focusing on software improvements, but this is not explicitly confirmed.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications:
- The document mentions "clinical tests" for MARIS validation, but it does not specify how ground truth was established for these tests, nor does it mention the number or qualifications of experts involved in any ground truth assessment. In the context of metal artifact reduction, "ground truth" might be subjective visual assessment by radiologists if not compared to a gold standard imaging modality.
4. Adjudication Method for the Test Set:
- The document does not specify any adjudication method (e.g., 2+1, 3+1). Given the lack of detail on expert involvement, it's unlikely a formal adjudication process was described for the submission.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done:
- No, an MRMC comparative effectiveness study was not done (or at least not described in this summary). The studies mentioned focus on validating the performance of features (MARIS, HD FoV Pro) in the device itself, not on comparing human reader performance with and without AI assistance from this specific device.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was Done:
- The document describes "bench tests were performed to verify and validate the performance of the MARIS and HD FoV Pro (HD FoV 2.0) features," which are likely standalone algorithm evaluations using phantoms or controlled datasets.
- "Clinical tests" were also performed for the MARIS algorithm, which would involve the algorithm processing clinical data. While these involve physicians interpreting the output of the CT system, the focus of the "clinical tests" was on validating the algorithm's performance (e.g., artifact reduction), rather than a human reading study. So, in terms of the algorithm itself, yes, standalone performance was assessed.
7. The Type of Ground Truth Used:
- For the "bench tests" of MARIS and HD FoV Pro, the ground truth would likely be phantom-based measurements and technical specifications. Phantoms provide a known, controlled environment to assess image quality, artifact reduction, and field of view accuracy.
- For the "clinical tests" of MARIS, the document does not explicitly state the type of ground truth used. In the context of artifact reduction, it could involve visual assessment by clinicians comparing images with and without MARIS, or a comparison to an established 'gold standard' image if available (e.g., a non-metallic scan of the same area if feasible). However, no specifics are provided.
8. The Sample Size for the Training Set:
- The document does not specify the sample size for any training set. This is not uncommon for 510(k) submissions where the software updates are incremental and rely on established engineering practices, rather than a deep learning model requiring a distinct, large training dataset. The MARIS algorithm is described as an "image reconstruction mode," implying an algorithmic approach rather than a machine learning model that undergoes explicit "training" on a labeled dataset.
9. How the Ground Truth for the Training Set Was Established:
- As the document does not mention a training set in the context of machine learning, there is no information on how its ground truth was established. For algorithmic development, the "training" (design and tuning) is based on engineering principles, image science, and potentially smaller, internally-derived datasets with known properties or simulated artifacts.
§ 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.