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The Dual Energy System allows the system to acquire two CT images of the same anatomical location using distinct tube voltages and/or tube currents during two tube rotations. The x-ray dose will be the sum of the dose of each tube rotation at its respective tube voltage and current. Information regarding the material composition of various organs, tissues, and contrast materials may be gained from the differences in x-ray attenuation between these distinct energies.

This information may also be used to reconstruct images at multiple energies within the available spectrum, and to reconstruct basis images that allow the visualization and analysis of anatomical and pathological materials.

The visualization of the differentiation between uric acid and non-uric acid stones greater than 3mm and the visualization of uric acid presence within surrounding anatomical structures is provided with the Dual Energy system. When used by a qualified physician, a potential application is to determine the course of treatment.

Performance of this device may be affected by body size and motion artifacts.

Dual Energy System Package, CSDP-001A, consists of three software packages intended to be used on Toshiba CT systems which allows for the acquisition of two CT images of the same anatomical location using different tube voltages and/or tube currents during two tube rotations.

CSDP-001A/1 (Dual Energy System) allows the same region to be scanned at two different tube voltages and tube currents and permits the CT values and ratio in the selected region to be measured based on the two image data sets obtained, providing information that is useful for identifying materials.

CSDP-001A/2 (Dual Energy Raw Data Analysis) allows monochromatic images to be generated and permits images in which contrast enhancement is visualized to be generated based on the datasets acquired by scanning the same positions with different tube voltages, making it possible to perform analysis.

CSDP-001A/3 (Dual Energy Composition Analysis) reads data acquired by scanning the same positions with different tube voltages and extracts suspected uric acids from the acquired images.

Here's an analysis of the acceptance criteria and the study proving the Toshiba Dual Energy System Package, CSDP-001A, meets these criteria, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

2. Sample Sizes and Data Provenance

• Test Set Sample Sizes:
  • Kidney Stone Analysis (Clinical): 12 patients.
  • Uric Acid Analysis (Clinical): 1 patient.
  • Iodine Map (Clinical): 1 patient.
  • Phantom Studies: Not specified in terms of "sample size," but involved custom phantoms and vials with known materials.
  • Motion Study: "CT image data obtained from cases with and without breathing," but the number of cases is not specified.
• Data Provenance: Not explicitly stated, but the submission is from Toshiba America Medical Systems, Inc., suggesting the studies were conducted or overseen by them. The text does not specify the country of origin for clinical cases. The studies appear to be prospective for the clinical data collected for the purpose of this submission, and likely internal for the phantom studies.

3. Number and Qualifications of Experts for Ground Truth

• Number of Experts: Not explicitly stated.
• Qualifications of Experts: Not explicitly stated. The text mentions "qualified physician" in the Indications for Use, implying medical supervision, but doesn't detail the qualifications of those interpreting the images or establishing ground truth for the studies.

4. Adjudication Method for the Test Set

• The document does not describe a formal adjudication method (e.g., 2+1, 3+1) for the interpretation of test set images. For the clinical kidney stone analysis, it states "Stone analysis of the resultant images was performed," without specifying who performed it or if there was a consensus process.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

• No MRMC comparative effectiveness study is reported in this summary. The studies focus on the standalone performance of the device or a very limited number of clinical cases. There is no mention of comparing human readers with and without AI assistance or any effect sizes for such comparisons.

6. Standalone (Algorithm Only) Performance

• Yes, the non-clinical (phantom) testing and the methodology described for the clinical studies largely represent standalone performance of the algorithm. The device's ability to differentiate materials, reduce artifacts, improve CNR, and quantitatively measure features (like uric acid differentiation and iodine concentration) is assessed directly through image analysis and comparison to known ground truth (phantoms, pathology). The clinical studies evaluate the direct output of the system and compare it to confirmed ground truth.

7. Type of Ground Truth Used

• Pathology:
  • Uric Acid Analysis (Clinical): Surgically extracted tissue confirmed by polarized microscopy analysis.
  • Kidney Stone Analysis (Clinical): Stone compositions confirmed using polarized microscopy.
• Known Composition in Phantoms:
  • Water phantom with known regions of uric acid, calcium inserts, and monosodium urate.
  • Custom phantom designed for beam hardening simulation.
  • Custom phantom containing tubes filled with varying concentrations of water/iodine.
  • Representative abdominal phantom with kidney stones of known material.
  • Vials with pure and mixed kidney stones.
  • Phantom designed to imitate various human body sizes with known composition kidney stones.
  • Water phantom with tubes filled with diluted contrast medium of varying concentrations.
• Clinical Observation/Outcome Inferential Ground Truth:
  • Iodine Map (Clinical): "Visualization of the ischemic region is possible due to the lack of contrast enhancement in the lower perfusion region." This implies clinical diagnosis or a strong clinical indicator of ischemia was the ground truth.

8. Sample Size for the Training Set

• The document does not provide any information regarding the sample size of a training set. This summary is focused on verification and validation testing, not the development or training process of the software.

9. How Ground Truth for the Training Set Was Established

• Since no information about a training set is provided, there is also no information on how ground truth for any training data was established.

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