(199 days)
The various materials of an anatomical region of interest have different attenuation coefficients, which depend on the used energy. These differences provide information on the chemical composition of the scanned body materials. syngo. CT Dual Energy combines images acquired with low and high energy spectra to visualize this information. Depending on the region of interest, contrast agents may be used.
The general functionality of the syngo.CT Dual Energy application is as follows:
- · Monoenergetic 1)
- · Brain Hemorrhage 1)
- · Gout Evaluation 1)
- · Lung Vessels 1)
- · Heart PBV
- · Bone Removal
- · Lung Perfusion 1)
- · Lung Mono 1 )
- · Liver VNC 1)
- · Monoenergetic Plus 1)
- · Virtual Unenhanced 1)
- Bone Marrow
- · Hard Plaques
- Rho/Z
- · Kidney Stones 1) 2)
- · SPR (Stopping Power Ratio)
- · SPP (Spectral Post-Processing Format) 1)
- · Optimum Contrast 1)
The availability of each feature depends on the Dual Energy scan mode.
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This functionality supports data from Siemens Healthineers Photon-Counting CT scanners acquired in QuantumPlus modes.
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Kidney Stones is designed to support the visualization of the chemical composition of kidney stones and especially the differentiation between uric acid stones. For full identification of the kidney stone, additional clinical information should be considered such as patient history and urine testing. Only a well-trained radiologist can make the final diagnosis upon consideration of all available information. The accuracy of identification is decreased in obese patients.
Dual energy offers functions for qualitative and quantitative post-processing evaluations. syngo.CT Dual Energy is a post-processing application consisting of several post-processing application classes that can be used to improve the visualization of the chemical composition of various energy dependent materials in the human body when compared to single energy CT. Depending on the organ of interest, the user can select and modify different application classes or parameters and algorithms.
Different body regions require specific tools that allow the correct evaluation of data sets. syngo.CT Dual Energy provides a range of application classes that meet the requirements of each evaluation type. The different application classes for the subject device can be combined into one workflow.
Here's an analysis of the acceptance criteria and study details for the syngo.CT Dual Energy device, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Feature/Application Class | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| DE Brain Hemorrhage (PCCT) | Visualization of iodine and identification of hemorrhage, iodine staining, or mixed features. | Demonstrated complementary visualization of iodine and overlay maps. In a two-reader study of 28 features, 24 were identified by both readers. Of these, 19 were pure hemorrhage, 6 pure iodine staining, and 3 a mix. |
| Lung Mono for Dual Source Dual Energy | Adequate agreement between obstructing clots and perfusion defects in Lung Mono maps. | Demonstrated adequate agreement between the position of obstructing clots and the location of perfusion defects in the Lung Mono maps. |
| Lung Analysis (Lung PBV, Lung Mono, Lung Vessels) for PCCT | Visualization of reduced local iodine content in lung parenchyma or arteries. | Shown to visualize reduced local iodine content, either in the lung parenchyma or in the lung arteries, based on obstructing clots identifiable in conventional CT by trained radiologists. |
2. Sample Size Used for the Test Set and Data Provenance
- DE Brain Hemorrhage (PCCT): 28 features (implicitly, from patient cases). Data provenance not specified (retrospective/prospective, country of origin).
- Lung Mono for Dual Source Dual Energy: 20 cases (of suspected pulmonary embolisms). Data provenance not specified.
- Lung Analysis (Lung PBV, Lung Mono, Lung Vessels) for PCCT: 33 cases (of suspected pulmonary embolisms). Data provenance not specified.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
- DE Brain Hemorrhage (PCCT): Two readers. Qualifications not specified beyond "readers."
- Lung Mono for Dual Source Dual Energy: Not explicitly stated for ground truth, but a "two-reader study" was performed for testing. Implicitly, radiologists are involved in identifying obstructing clots.
- Lung Analysis (Lung PBV, Lung Mono, Lung Vessels) for PCCT: Not explicitly stated for ground truth, but a "two-reader study" was performed for testing. Implicitly, "trained radiologists" identify obstructing clots in conventional CT images.
4. Adjudication Method for the Test Set
Not specified. The studies mention "two-reader study," but whether there was an adjudication for discrepancies (e.g., 2+1, 3+1) is not provided.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance
It appears standalone studies were performed for the "DE Brain Hemorrhage," "Lung Mono," and "Lung Analysis" features. There is no mention of a comparative effectiveness study evaluating the improvement of human readers with AI assistance versus without AI assistance. The studies assess the device's ability to provide information; they do not quantify a human reader's performance change with the device.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
The performance data described are related to the device output's ability to visualize certain conditions effectively, implying a standalone (or heavily algorithm-driven) assessment of the generated images/maps. For example, for "DE Brain Hemorrhage," it "demonstrated complementary visualization." For "Lung Mono," it "demonstrated adequate agreement." However, the mention of "two-reader studies" suggests human interpretation of the images generated by the device, rather than a purely algorithmic output without any human involvement in the evaluation of the results. It's an assessment of the utility of the device's output.
7. The Type of Ground Truth Used
The ground truth implicitly relies on:
- Follow-up data: For DE Brain Hemorrhage, comparing reading results "with later follow-up data."
- Expert Consensus/Clinical Standard: For Lung Mono and Lung Analysis, the identification of obstructing clots in conventional CT images by "trained radiologists" serves as the reference, suggesting a clinical gold standard interpreted by experts.
8. The Sample Size for the Training Set
The document does not provide details regarding the training set size for any of the features. The performance data section focuses entirely on validation studies.
9. How the Ground Truth for the Training Set Was Established
Since no information is provided on the training set, how its ground truth was established is also not detailed in this document.
§ 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.