The Siemens SOMATOM Definition Flash system is 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.

In addition the SOMATOM Definition Flash is able to produce additional image planes and analysis results by executing optional post processing features, which operate on DICOM images.

The images and results delivered by the system can be used by a trained physician as an aid in diagnosis.

(*spiral planes: the axial planes resulting from the continuous rotation of detectors and x-ray tube, and the simultaneous translation of the patient.)

Device Description

The Siemens SOMATOM Definition Flash is a Computed Tomography X- ray System, which features two continuously rotating tube-detector systems and functions according to the fan beam principle. The SOMATOM Definition Flash 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, SOMARIS/7 VA44, allows the reconstruction of images with a slice thickness of 0.5mm for SOMATOM Definition Flash systems equipped with Stellar Detector.

The computer system delivered with the CT scanner is able to run the post processing applications optionally. The Stellar Detector will be offered as an optional upgrade to the cleared SOMATOM Definition Flash CT systems.

AI/ML Overview

The provided text describes a 510(k) submission for the SOMATOM Definition Flash CT System, focusing on modifications introduced with software version SOMARIS/7 VA44. The key modification is the ability to reconstruct 0.5mm slices for systems equipped with Stellar Detector and SAFIRE, providing a z-axis resolution of 0.3mm. The submission details non-clinical testing to support these modifications.

However, the provided text does not contain a table of acceptance criteria or reported device performance metrics in the way typically expected for a detailed study report. Instead, it focuses on demonstrating substantial equivalence to predicate devices through technical characteristic comparisons and non-clinical testing.

Here's an attempt to answer the questions based on the available information, highlighting what is missing or not explicitly stated:

Acceptance Criteria and Device Performance

The document does not explicitly state quantitative acceptance criteria or a table of reported device performance values in the context of a clinical study or a formal validation report against specific performance targets (e.g., sensitivity, specificity for a diagnostic task).

Instead, the "acceptance criteria" appear to be implicit in the non-clinical testing performed, which aimed to confirm the technical capabilities of the new software feature (0.5mm slice reconstruction).

Implicit Acceptance Criteria and Reported Performance (from non-clinical testing):

Acceptance Criteria (Implied)	Reported Device Performance
Ability to reconstruct 0.5mm slices.	New software provides a mode allowing reconstruction of 0.5mm slices.
Z-axis resolution with 0.5mm slices.	Provides a z-axis resolution of 0.3mm.
Modulation Transfer Function (MTF) for 0.5mm slice thickness.	Assessed via Fourier sensitivity transformation of slice sensitivity profiles. (Specific values not provided)
Detectable spatial frequency in the z-direction.	Determined (Specific values not provided)
Lines per centimeter with respect to the z-axis.	Accessed (Specific values not provided)
Dual Energy Workflow enhancements (auto-reconstruction, 3D support).	Dual energy combined images can be automatically reconstructed. 3D reconstruction supports dual energy image data. (Qualitative)

Study Details

Sample size used for the test set and the data provenance:
- The document describes "phantom tests" to evaluate the 0.5mm slice width.
- Test Set Sample Size: Not specified. Phantom studies typically involve multiple acquisitions or varying phantom configurations, but the number of "samples" or "cases" is not quantified.
- Data Provenance: Phantom data (simulated/controlled environment). No human patient data is mentioned for this specific testing.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable/Not mentioned. Phantom studies typically do not involve human experts establishing ground truth in the same way clinical studies do. The "ground truth" for phantom measurements is based on the known physical properties and geometry of the phantom and the expected output based on theoretical understanding or established measurement techniques.
Adjudication method for the test set:
- Not applicable. As this was non-clinical phantom testing, no expert adjudication was involved. The measurements are objective physical assessments.
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. The document explicitly states "Nonclinical Testing" and describes phantom tests. There is no mention of an MRMC study or any assessment of human reader performance or AI assistance. This device is a CT scanner, and the modifications are about image reconstruction capabilities, not an AI-assisted diagnostic tool for human readers.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, to some extent. The non-clinical testing of the software focuses on the performance of the image reconstruction algorithm itself using phantom data (e.g., measuring MTF, spatial resolution). This can be considered a standalone assessment of the algorithm's capability to produce specific image characteristics.
The type of ground truth used:
- For the non-clinical phantom testing, the ground truth is derived from known physical properties and characteristics of the phantoms used (e.g., precisely manufactured structures for resolution assessment) and established measurement methodologies for CT performance.
The sample size for the training set:
- Not applicable/Not mentioned. This submission does not describe an AI model that requires a training set. The software update is for image reconstruction logic and hardware capabilities, not a machine learning algorithm in the typical sense that would necessitate a trained model.
How the ground truth for the training set was established:
- Not applicable. As no training set for an AI model is mentioned, there's no ground truth establishment for such a set.

Summary

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Special 510(k) Submission: SOMATOM Definition Flash CT System

MAY - 8 2012

510(K) SUMMARY FOR SOMATOM Definition Flash

Submitted by:

Siemens Medical Solutions USA, Inc.

51 Valley Stream Parkway Malvern, PA 19355

Date Prepared: May 4, 2012

This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR §807.92.

1. Contact Person:
  Mrs. Kimberly Mangum Technical Specialist, Regulatory Affairs Submissions Siemens Médical Solutions, Inc. USA 51 Valley Stream Parkway D02 Malvern, PA 19355-1406 Phone: (601) 448-1772 Fax: (610) 448-1778 Email: kimberly.mangum@siemens.com

2. Device Name and Classification

Product Name:	SOMATOM Definition Flash
Propriety Trade Name:	SOMATOM Definition Flash
Classification Name:	Computed Tomography X-ray System
Classification Panel:	Radiology
CFR Section:	21 CFR §892.1750
Device Class:	Class II
Product Code:	90JAK

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Substantial Equivalence: 3.

Siemens SOMATOM Definition Flash Computed Tomography X-ray systems, configured with software version SOMARIS/7 VA44 is substantially equivalent to the following medical device in commercial distribution:

Predicate Device Name	FDA Clearance Number	FDA Clearance Date
Siemens SOMATOM Definition Flash(with SOMARIS7/ VA40)	K082220	10/10/2008
Siemens SOMATOM Definition Flash(with Stellar Detector)(with SOMARIS7/ VA40)	K113342	12/29/2011

4. Device Description:

5. Summary of Technical Characteristics of the Subject Device as Compared with the Predicate Device:

The modified SOMATOM Definition Flash CT Systems configured with software version SOMARIS/7 VA44 will be marketed under the trade name SOMATOM Definiton Flash. The modifications introduced with software version SOMARIS/7 VA 44 are as follows:

o Within the Dual Energy Workflow it is now possible to automatically reconstruct dual energy combined images. Furthermore the 3D reconstruction will now

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support dual energy image data.

For systems using Stellar Detector (cleared in Premarket Notification K113342 on o 12/29/2011) and SAFIRE (cleared in Premarket Notification K103424 on 11/22/2011) the new software provides a mode, which allows the reconstruction of 0.5mm slices without using UHR option Using a reconstruction of 0.5mm slices provides a z-axis resolution of 0.3mm.
The modified SOMATOM Definition Flash CT Systems configured with software version SOMARIS/7 VA44 as described in this premarket notification has similar intended use and fundamental scientific technical characteristics as the predicate devices.

Q. Nonclinical Testing:

SIEMENS

The modifications described in this premarket notification were supported with verification/validation testing as well as phantom tests to evaluate 0.5 mm slice width. Fourier sensitivity transformation of the slice sensitivity profiles with respect to the z-coordinate was assessed to determine the modulation transfer function for 0.5 mm slice thickness. Phantom testing was also performed to determine the detectable spatial frequency in the z-direction, and access the lines per centimeter with respect to the z-axis.

7. Indications for Use:

The Siemens SOMATOM Definition Flash system is intended to produce crosssectional 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.

In addition the SOMATOM Definition Flash is able to produce additional image planes and analysis results by executing optional post processing features, which operate on DICOM images.

The images and results delivered by the system can be used by a trained physician as an aid in diagnosis.

(* spiral planes: the axial planes resulting from the continuous rotation of detectors and x- ray tube, and the simultaneous translation of the patient.)

General Safety and Effectiveness Concerns: 8.

The device labeling contains instructions for use and any necessary cautions and warnings, to provide for safe and effective use of the device.

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SIEMENS

Risk management is ensured via a hazard analysis, which is used to identify potential hazards. These potential hazards are controlled during development, verification and validation testing. To minimize electrical, mechanical, and radiation hazards, Siemens adheres to recognized and established industry practice and standards.

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Image /page/4/Picture/0 description: The image shows the logo for the Department of Health & Human Services - USA. The logo features a stylized eagle with its wings spread, and the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular pattern around the eagle. The logo is black and white.

DEPARTMENT OF HEALTH & HUMAN SERVICES

Public Health Service

Food and Drug Administration 10903 New Hampshire Avenue Document Control Room - WO66-G609 Silver Spring, MD 20993-0002

MAY - 8 2012

Ms. Kimberly Mangum Regulatory Affairs Specialist Siemens Medical Systems. Inc. 51 Valley Stream Parkway MALVERN PA 19355

Re: K121072

Trade/Device Name: SOMATOM Definition Flash Regulation Number: 21 CFR 892.1750 Regulation Name: Computed tomography x-ray system Regulatory Class: II Product Code: JAK Dated: March 23, 2012 Received: April 9, 2012

Dear Ms. Mangum:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into class II (Special Controls), it may be subject to such additional controls. Existing major regulations affecting your device can be found in Title 21, Code of Federal Regulations (CFR), Parts 800 to 895. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean I hat FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must or any i vith all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of

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medical device-related adverse events) (21 CFR 803); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820). This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Parts 801 and 809), please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (301) 796-5450. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to

http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely Yours. Janine M. Morris

Acting Director Division of Radiological Devices Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

. Enclosure

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510(k) Number (if known): K12|072

Device Name:

SOMATOM Definition Flash

Indications for Use:

In addition the SOMATOM Definition Flash is able to produce additional image planes and analysis results by executing optional post processing features, which operate on DICOM images.

The images and results delivered by the system can be used by a trained physician as an aid in diagnosis.

(*spiral planes: the axial planes resulting from the continuous rotation of detectors and x-ray tube, and the simultaneous translation of the patient.)

Prescription Use AND/OR (Part 21 CFR 801 Subpart D)

Over-The-Counter Use (21 CFR 801 Subpart C)

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE OF NEEDED)

Concurrence of CDRH, Office of In vitro Diagnostic Device (OIVD)

Arshad D'Okhai

vision Sign-Off Office of In Vitro Diagnostic Device Evaluation and Safety

K121672

Regulation Number and Section

§ 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.