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Vantage Orian 1.5T systems are indicated for use as a diagnostic imaging modality that produces cross-sectional transaxial, coronal, sagittal, and oblique images that display anatomic structures of the head or body. Additionally, this system is capable of non-contrast enhanced imaging, such as MRA.

MRI (magnetic resonance imaging) images correspond to the spatial distribution of protons (hydrogen nuclei) that exhibit nuclear magnetic resonance (NMR). The NMR properties of body tissues and fluids are:

·Proton density (PD) (also called hydrogen density) ·Spin-lattice relaxation time (T1) ·Spin-spin relaxation time (T2)

·Flow dynamics

·Chemical Shift

Depending on the region of interest, contrast agents may be used. When interpreted by a trained physician, these images yield information that can be useful in diagnosis.

The Vantage Orian (Model MRT-1550) is a 1.5 Tesla Magnetic Resonance Imaging (MRI) System. The Vantage Orian uses 1.4 m short and 3.8 tons light weight magnet. It includes the Pianissimo™ technology (scan noise reduction technology). The design of the gradient coil and the WB coil of the Vantage Orian 1.5T provides the maximum field of view of 55 x 50 cm. The Model MRT-1550/AC, AD, AG, AH includes the standard gradient system and Model MRT-1550/AK, AL, AO, AP includes the XGO gradient system.

This system is based upon the technology and materials of previously marketed Canon Medical Systems MRI systems and is intended to acquire and display cross-sectional transaxial, coronal, sagittal, and oblique images of anatomic structures of the head or body. The Vantage Orian MRI System is comparable to the current 1.5T Vantage Orian MRI System (K202767), cleared January 15th, 2021.

The provided document is a 510(k) summary for the Canon Medical Systems' Vantage Orian 1.5T MRI system, specifically for an extension of the Compressed SPEEDER (2D) maximum acceleration factor. The study described focuses on demonstrating that the extended acceleration factors (3.0 and 4.0) maintain equivalent performance to the previously cleared acceleration factor of 2.5.

Here's a breakdown of the requested information based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state quantitative acceptance criteria in numerical form for metrics like sensitivity, specificity, or image quality scores. Instead, the acceptance criterion for the study appears to be a qualitative equivalence between the higher acceleration factor images and the predicate 2.5 acceleration factor images.

Note: The document describes a preference study rather than a study assessing diagnostic accuracy directly. The acceptance criteria are therefore stated in terms of preference and equivalent performance.

2. Sample Size and Data Provenance

• Sample Size for Test Set: 34 studies
• Data Provenance: The document does not explicitly state the country of origin or whether the data was retrospective or prospective. It mentions "volunteer clinical imaging" which suggests prospective data collection.

3. Number of Experts and Qualifications for Ground Truth

• Number of Experts: Three board-certified radiologists per anatomy.
• Qualifications of Experts: Board-certified radiologists. (No mention of years of experience).

4. Adjudication Method

The document describes a "Human observer study" where radiologists assessed "preference." It does not specify a formal adjudication method (like 2+1 or 3+1 consensus) for establishing a single "ground truth" for the test set. Instead, it suggests individual preferences were aggregated to determine if there was a clinically relevant difference in preference. The phrasing "demonstrated no clinically-relevant difference in preference" implies that a consensus or aggregation of these preferences led to this conclusion.

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

No, a multi-reader multi-case (MRMC) comparative effectiveness study assessing human readers' improvement with AI vs. without AI assistance was not explicitly described. This study was a comparison of different acceleration factors using the same AI reconstruction (Compressed SPEEDER 2D). The AI (AiCE Reconstruction Processing Unit) is a component of the device, and the study assessed the impact of varying one of its parameters (acceleration factor) on image preference. It was not a comparison of human readers using AI versus not using AI.

6. Standalone (Algorithm Only) Performance

The study was a "Human observer study," meaning it involved human interpretation of the images produced by the algorithm. It does not explicitly mention a standalone (algorithm only) performance evaluation without human-in-the-loop. The focus was on how humans perceive the images generated by the different acceleration factors.

7. Type of Ground Truth Used

The "ground truth" in this context is indirect. It is not pathology, outcomes data, or a pre-established "correct diagnosis." Instead, the "ground truth" for the performance comparison was the preference of board-certified radiologists for one set of images (higher acceleration) compared to another (predicate 2.5 acceleration). The goal was to establish that there was no clinically relevant difference in preference, suggesting visual equivalence.

8. Sample Size for Training Set

The document does not provide information on the sample size used for the training set of the AiCE Reconstruction Processing Unit. The study described focuses on validating the extension of an existing feature (Compressed SPEEDER 2D) and implies no changes to the core AiCE software or hardware.

9. How Ground Truth for Training Set Was Established

The document does not provide information on how the ground truth for the training set of the AiCE Reconstruction Processing Unit was established.

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Vantage Orian 1.5T systems are indicated for use as a diagnostic imaging modality that produces cross-sectional transaxial, coronal, sagittal, and oblique images that display anatomic structures of the head or body. Additionally, this system is capable of non-contrast enhanced imaging, such as MRA.

MRI (magnetic resonance imaging) images correspond to the spatial distribution of protons (hydrogen nuclei) that exhibit nuclear magnetic resonance (NMR). The NMR properties of body tissues and fluids are:

·Proton density (PD) (also called hydrogen density)

• ·Spin-lattice relaxation time (T1)
• ·Spin-spin relaxation time (T2)
• ·Flow dynamics
• ·Chemical Shift

Depending on the region of interest, contrast agents may be used. When interpreted by a trained physician, these images yield information that can be useful in diagnosis.

The Vantage Orian (Model MRT-1550) is a 1.5 Tesla Magnetic Resonance Imaging (MRI) System. The Vantage Orian uses 1.4 m short and 3.8 tons light weight magnet. It includes the Pianissimo™ technology (scan noise reduction technology). The design of the gradient coil and the WB coil of the Vantage Orian 1.5T provides the maximum field of view of 55 x 50 cm. The Model MRT-1550/AC, AD, AG, AH includes the standard gradient system and Model MRT-1550/AK, AL, AO, AP includes the XGO gradient system.

AiCE is an optional noise reduction algorithm that improves image quality and reduces thermal noise by employing Deep Convolutional Neural Network methods. AiCE is designed to remove Gaussian distributed noise in MR images for reducing contributions of thermal noise. In order to train a DCNN that can learn a model that represents thermal noise, the training datasets are created by adding Gaussian noise of different amplitudes to high-SNR images acquired with large number of averages. The device is targeted for Brain and knee regions. This software and its associated hardware are used on Canon MRI systems that are designed to communicate with the AiCE Reconstruction Processing Unit for MR.

This system is based upon the technology and materials of previously marketed Canon Medical Systems MRI systems and is intended to acquire and display cross-sectional transaxial, coronal, sagittal, and oblique images of anatomic structures of the head or body. The Vantage Orian 1.5T, MRT-1550, V6.0 with AiCE Reconstruction Processing Unit for MR is comparable to the current 1.5T Vantage Orian MRI System (K193021), cleared June 3rd, 2020 with the following modifications.

The provided text describes the Canon Medical Systems Corporation's Vantage Orian 1.5T, MRT-1550, V6.0 with AiCE Reconstruction Processing Unit for MR. Here's a breakdown of the acceptance criteria and the study details:

1. Acceptance Criteria and Reported Device Performance

The document doesn't explicitly state "acceptance criteria" in a tabulated format with specific numerical targets. Instead, it describes performance goals and how the device performed against them. The key performance goals for AiCE are:

• Improved Image Quality and Reduced Thermal Noise: Achieved by employing Deep Convolutional Neural Network methods.
• Maintained or Improved Low Contrast Detectability: Verified through a model observer study.
• Increased Signal-to-Noise Ratio (SNR) and Maintained Contrast: Demonstrated through measurements on clinical brain and knee images.
• Performance at or Above Predicate Device: Indicated by the human observer study's finding of a statistical preference for AiCE.

2. Sample Size Used for the Test Set and Data Provenance

• Sample Size for Test Set: 160 image data sets for the human observer study.
• Data Provenance: Not explicitly stated, but the mention of "volunteer clinical imaging" suggests it was likely prospective data collected from volunteers. The regions targeted were "Brain and knee regions." Given the manufacturer is based in Japan, and the U.S. agent is in California, the data could originate from various geographical locations. The document does not specify the country of origin or if it was retrospective.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications

• Number of Experts: 6 board certified radiologists.
• Qualifications of Experts: Board certified radiologists. The document does not specify their years of experience.

4. Adjudication Method for the Test Set

• The document does not specify an adjudication method like 2+1 or 3+1 for establishing ground truth from the expert readers. It states the human observer study "demonstrated a statistical preference of AiCE when compared to other performance filters," implying a comparative assessment rather than a consensus-driven ground truth establishment for a diagnostic task.

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

• Yes, a human observer study was done. The document states: "Additionally, a human observer study was conducted with 6 board certified radiologists and 160 image data sets that demonstrated a statistical preference of AiCE when compared to other performance filters."
• Effect Size: The document mentions "a statistical preference of AiCE" and that AiCE performed "either at the same level or above the performance of the commercially available predicate device." However, it does not provide a specific quantitative effect size (e.g., AUC difference, sensitivity/specificity improvement, or change in reader confidence scores) for how much human readers improved with AI vs. without AI assistance. The study seems to have focused on whether AiCE images were preferred or performed better, implying an improvement or at least equivalence.

6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study

• Yes, a standalone study was done in the form of a "model observer study" and direct measurements.
  • "AiCE deep learning reconstruction underwent performance (bench testing) using a model observer study to determine that image low contrast detectability was maintained or improved."
  • "In order to quantify the increase in SNR with AiCE over standard protocols, SNR measurements of sample clinical brain and knee images were obtained. Additionally, contrast was measured using the absolute signal intensity differences between two tissues." These are measurements of the algorithm's direct output on image quality metrics.

7. Type of Ground Truth Used

• For the standalone tests (model observer, SNR/contrast measurements): The ground truth was based on objective image quality metrics (low contrast detectability, SNR, contrast). For training the DCNN, high-SNR images acquired with a large number of averages were considered the "high quality" reference from which noisy images were created.
• For the human observer study: The "ground truth" was the "statistical preference" of the 6 board-certified radiologists when comparing AiCE images to images from other performance filters. This isn't a traditional diagnostic ground truth (like a biopsy result) but rather a preference-based assessment of image quality and clinical utility from experienced readers.

8. Sample Size for the Training Set

• The document states: "In order to train a DCNN that can learn a model that represents thermal noise, the training datasets are created by adding Gaussian noise of different amplitudes to high-SNR images acquired with large number of averages."
• The specific sample size (number of images or cases) for the training set is not provided.

9. How the Ground Truth for the Training Set Was Established

• The ground truth for the training set was established through a synthetic process:
  • "High-SNR images acquired with large number of averages" were used as the reference "clean" images.
  • "Gaussian noise of different amplitudes" was then "added" to these high-SNR images to create noisy counterparts.
  • The DCNN was trained to learn how to transform the noisy images back to the high-SNR (ground truth) images, effectively modeling and removing the noise.

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