(192 days)
The CT Dual Energy Image View application accepts CT images acquired using different tube voltages and/or tube currents of the same anatomical location. The material composition of body regions may be determined using the energy dependence of the attenuation coefficients of different materials. This approach enables images to be generated at multiple energies within the available spectrum to visualize and analyze information about anatomical and pathological structures.
The Vitrea® CT Dual Energy Image View is a post-processing software application which functions on the Vitrea® Platform, cleared by K150258.This application allows you to load and combine two CT images, acquired from a Toshiba CT scanner with a Dual Energy protocol, of the same anatomical location; one obtained with low kV tube voltage and one obtained with high kV tube voltage. Vitrea® computes a Blended and an Enhanced image with adjustable virtual energy levels, a Virtual Non-Contrast (VNC) image, an lodine Map overlaid on one of the original or derived images, a CT graph, and a best Contrast-to-Noise Ratio (CNR) image. For the Raw Data Analysis workflow, Vitreally calculates a Monochromatic image.
The software supports Toshiba dual-energy studies containing image-based and projection-based reconstruction techniques.
- lmage-based reconstructed data consists of a standard image reconstruction of the two ● scans. Use the Dual Energy Image Domain (Two Volumes) workflow for these datasets.
- Projection-based reconstructed data consists of special material image reconstruction where . the two scans are combined to create two sets of images where a predefined material is defined, typically lodine/Water and/or Calcium/Water. Use the Dual Energy Raw Data Analysis (Four or Six Volumes) workflow for these datasets.
- NOTE: It is important that a description of the material is contained in the DICOM Image Comments tag (0020, 4000) for each dataset at the time of the scan. For lodine/Water projection-based reconstruction, the lodine material image should be labeled "I/H20," and the corresponding Water material image should be labeled "H20/1." For the Calcium/Water projection-based reconstruction, the Calcium material image should be labeled "Ca/H20," and the corresponding Water material image should be labeled "H20/Ca."
NOTE: The dual-energy datasets must be coincident with the same frame of reference UID.
NOTE: Available with Toshiba datasets only.
Here's a summary of the acceptance criteria and the study conducted for the Vital Images, Inc. Vitrea® CT Dual Energy Image View device, based on the provided text:
Important Note: The provided document is a 510(k) summary, which focuses on demonstrating substantial equivalence to a predicate device rather than presenting a detailed independent study with specific numerical acceptance criteria and performance metrics for the new device. Therefore, the "acceptance criteria" discussed are largely qualitative and relate to the device functioning as intended and being comparable to the predicate, rather than precise quantitative thresholds. Similarly, "reported device performance" is described qualitatively as meeting those intentions.
Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Qualitative) | Reported Device Performance (Qualitative) |
|---|---|
| Software operates according to defined requirements (functional, performance, and safety). | All external validation testing passed with each expert confirming the Vitrea® CT Dual Energy Image View software fulfills the intended use and meets the needs of the user. |
| Functionality (e.g., Iodine maps, Virtual Non-Contrast, Monochromatic images, Best CNR, Blended images, Enhanced images at different energy levels) is present and works as intended. | The clinical radiologist rated the quality and performance of each feature as establishing equivalence to the predicate device. |
| User interface and usability are acceptable to trained professionals. | Two Radiological Technologists provided positive feedback regarding performance and usability of each feature. |
| Safety risks are reduced as low as possible, and benefits outweigh residual risks. | All risks for this feature were collectively reviewed to determine if the benefits outweigh the risk, and it was assessed that the benefits do outweigh the risks. |
| Substantial equivalence to the predicate device (K132813) in terms of intended use, indications for use, principle of operation, and technological characteristics. | The device was found substantially equivalent to the predicate device across all these criteria, with noted minor differences not raising new safety/effectiveness questions. |
Study Details
2. Sample size used for the test set and the data provenance:
-
Test Set (External Validation):
- Clinical Radiologist: Evaluated "multiple test cases." The exact number of cases is not specified.
- Radiological Technologists (2): Provided feedback on "a series of questions."
- Data Provenance: The document does not explicitly state the country of origin or whether the data was retrospective or prospective. Given the context of comparing to a predicate device, it's likely existing data or a simulated environment was used, but this is not confirmed.
-
Test Set (Internal Validation / Phantom Testing):
- Sample Size: "Various phantoms." The exact number or types are not specified.
- Data Provenance: Not specified, but likely generated internally for phantom testing.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Number of Experts: Three experienced clinical experts were involved in the external validation of the software's features. Specifically, one clinical radiologist and two radiological technologists.
- Qualifications: "Experienced clinical experts," "clinical radiologist," and "Radiological Technologists." Specific years of experience or board certifications are not provided.
4. Adjudication method for the test set:
- The document does not describe a formal adjudication method (like 2+1 or 3+1 consensus).
- Instead, it states that the clinical radiologist evaluated test cases comparing the subject device to the predicate device and rated "quality and performance." The two radiological technologists provided feedback on performance and usability.
- The conclusion states that "All external validation testing passed with each expert confirming the Vitrea® CT Dual Energy Image View software fulfills the intended use and meets the needs of the user," implying individual expert agreement rather than a formal consensus process between them for ground truth.
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 MRMC comparative effectiveness study was done in the sense of evaluating human reader performance with and without AI assistance to quantify improvement.
- The study involved comparing the new device's output and usability to a predicate device by expert users. It was a comparison of tool equivalence rather than an assessment of human performance augmentation.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- The device is a "post-processing software application."
- "Internal Validation (Phantom Testing)" included "side-by-side visual comparisons of dual energy algorithm outputs with Toshiba Display Console as the predicate device using phantom data." This indicates some form of standalone evaluation against a reference/predicate system, but it's not explicitly framed as an "algorithm-only" performance study in isolation from any human interpretation. However, the direct comparison of "algorithm outputs" suggests an assessment of the algorithm's results themselves.
7. The type of ground truth used:
- For the external validation, the ground truth was effectively the expert opinion/comparison of the clinical radiologist against the output of the predicate device (Toshiba Dual Energy System Package K132813). The experts assessed whether the new device's features produced images of comparable "quality and performance" and fulfilled the "intended use."
- For internal validation (phantom testing), the "Toshiba Display Console" served as the reference for "side-by-side visual comparisons of dual energy algorithm outputs," implying its output was considered the reference or "ground truth" for comparison.
8. The sample size for the training set:
- The document does not mention a training set or any machine learning/AI model training. The Vitrea® CT Dual Energy Image View is described as a "post-processing software application" that "computes" various images based on acquired CT data. It does not appear to be an AI/ML device that requires a training set in the conventional sense. The "algorithm" mentioned refers to the computational methods for generating the dual-energy derived images, not a learned model.
9. How the ground truth for the training set was established:
- As no training set is mentioned (see point 8), this information is not applicable.
§ 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.