Perfusion CT is an application software package that permits cerebral perfusion imaging based on dynamic CT images continuously acquired after the injection of contrast. The package allows visualization of apparent blood flow in brain tissue and pictorially illustrates perfusion related parameters (i.e. relative cerebral blood flow, relative cerebral blood volume, time to peak). By generating images of cerebral blood flow (CBF), cerebral blood volume (CBV), and local bolus timing (i.e. time to peak) from one set of dynamic CT images, Perfusion CT aids the physician in the assessment of the type and extent of cerebral perfusion disturbances. The software package also allows the calculation of mirrored regions of interest and the visual inspection of time density curves.

Device Description

Perfusion CT is a post-processing software package which runs on an Intel-based PC platform designed to post-process images acquired with SOMATOM CT scanners which meet certain minimal requirements (i.e. Siemens SOMATOM Plus 4, SOMATOM AR.STAR, SOMATOM Classic). It is a package containing evaluation software that supports the evaluation of Dynamic CT data gathered after the injection of a compact bolus of contrast media, where the contrast media acts as a pure intravascular tracer.

Perfusion CT calculates the parameters related to brain perfusion and cerebral blood flow (CBF) using a simple linear relationship between the detected change of signal and the actual concentration of contrast media.

AI/ML Overview

The Perfusion CT Software Package for SOMATOM CT Systems is a post-processing software package that aids physicians in assessing cerebral perfusion disturbances.

Here's an analysis of its acceptance criteria and the supporting study:

1. Table of Acceptance Criteria and Reported Device Performance:

The provided document does not explicitly state quantitative acceptance criteria (e.g., specific sensitivity, specificity, or error rates) or reported device performance metrics (e.g., 90% accuracy). Instead, it focuses on qualitative utility and equivalence to predicate devices.

Acceptance Criteria (Implied)	Reported (Qualitative) Device Performance
Functionality: Calculate and visualize cerebral perfusion parameters (CBF, CBV, time to peak).	The device calculates parameters related to brain perfusion and cerebral blood flow (CBF) using a simple linear relationship. It generates images of CBF, CBV, and local bolus timing from dynamic CT images. The software package also allows the calculation of mirrored regions of interest and the visual inspection of time density curves.
Aids in Diagnosis: Useful in assessing type and extent of cerebral perfusion disturbances and diagnosing ischemia.	Clinical studies showed that the Perfusion CT post-processing software package is useful in aiding physicians in diagnosing ischemia. It aids the physician in the assessment of the type and extent of cerebral perfusion disturbances.
Substantial Equivalence: Similar technological characteristics and intended use as predicate devices.	The Perfusion CT software package has the same technological characteristics as the predicate Xenon CT and Dynamic CT, except it provides additional post-processing information. Both require contrast medium, rapid image scanning, and physician intervention.

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

Sample Size for Test Set: Not specified. The document states "Clinical studies were carried out in Europe to collect cerebral images from individuals with suspected local ischemia." It does not provide the number of patients or cases.
Data Provenance: Europe. This was a clinical study. It does not specify whether the clinical studies were retrospective or prospective.

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

Not specified. The document states the software is "useful in aiding physicians in diagnosing ischemia," suggesting physician involvement in assessing the output, but it does not detail how ground truth was established or the number/qualifications of experts involved in the clinical studies.

4. Adjudication Method for the Test Set:

Not specified.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size:

Not specified. The document does not mention an MRMC study or any comparison of human readers with vs. without AI assistance, nor does it provide an effect size.

6. If a Standalone (Algorithm Only) Performance Study Was Done:

The description of the "Clinical Studies and Conclusion" focuses on the software's utility in aiding physicians. There is no explicit mention of a standalone algorithm-only performance study, nor are there quantitative metrics that would typically result from such a study (e.g., sensitivity, specificity, AUC). The device is described as a "post-processing software package" that "aids the physician," implying human-in-the-loop performance.

7. The Type of Ground Truth Used:

Not explicitly stated. Given that the software "aids the physician in the assessment of the type and extent of cerebral perfusion disturbances" and "diagnosing ischemia," it is implied that the ground truth for "diagnosing ischemia" would likely be through clinical diagnosis, potentially supported by other imaging modalities or follow-up clinical outcomes, rather than just expert consensus on the software's output alone. However, the exact reference standard is not detailed.

8. The Sample Size for the Training Set:

Not specified. The document focuses on performance evaluation rather than development.

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

Not specified. The document does not provide details about development or training data.

Summary

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NOV 24 1998

ATTACHMENT 8

510(K) SUMMARY

Perfusion CT Software Package for the SOMATOM CT Systems

Submitted by:

Siemens Medical Systems, Inc. 186 Wood Avenue South Iselin, NJ 08830

November 23, 1998

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

1. Contact Person:

Ms. Malgorzata Stanek Phone: (732) 321-3950 Fax: (732) 321-4841

2. Device Name and Classification:

Trade Name:	Perfusion CT Software Package
Classification Name:	Computed Tomography X-ray System
CFR Section:	21 CFR §892.1750, Class II
Device Code:	90JAK

3. Substantial Equivalence:

The Perfusion CT software package designed for post processing images that have been continuously acquired with computed tomography (CT) imaging systems meeting certain minimal requirements (i.e. Siemens SOMATOM Plus 4, SOMATOM AR.STAR, SOMATOM Classic), is substantially equivalent to the following devices:

SIEMENS Device Name	FDA Clearance Number	FDA Clearance Date
Xenon CT	K875088	6/26/88
Dynamic CT option(Somatom AR)	K910859	5/15/91
(Somatom Plus)	K880965	3/28/88

Perfusion CT images, as compared with Xenon CT images and Dynamic CT images, are acquired in the same manner: injection of contrast media followed by CT scanning. In addition, like the predicate devices, Perfusion CT is a postprocessing evaluation package and as such do not affect the dosage characteristics or the imaging performance parameters of the Siemens CT scanners.

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4. Device Description:

5. Intended Use of the Device:

6. Summary of Technological Characteristics of the Device Compared to the Predicate Device:

The Perfusion CT software package has the same technological characteristics as the predicate Xenon CT and Dynamic CT, except that Perfusion CT provides the user with additional post-processing information related to brain perfusion. They both require the use of a contrast medium, rapid image scanning, and the intervention of a physician in setting necessary parameters and in assessing resultant images.

7. Clinical Studies and Conclusion:

Clinical studies were carried out in Europe to collect cerebral images from individuals with suspected local ischemia. The results from the studies showed that the Perfusion CT post-processing software package is useful in aiding physicians in diagnosing ischemia.

Kathleen Rutherford

Kathleen Rutherford Manager, Regulatory Submissions Siemens Medical Systems, Inc.

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Image /page/2/Picture/0 description: The image shows the seal of the Department of Health & Human Services USA. The seal is circular and contains the words "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" around the top half of the circle. In the center of the seal is an abstract image of an eagle with its wings spread. The eagle is facing to the right.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

NOV 24 10988

Malgorzata Stanek Technical Specialist Regulatory Submissions Siemens Medical Systems, Inc. 186 Wood Avenue South Iselin, NJ 08830

Re: K982536

Perfusion CT Software Package Dated: November 17. 1998 Received: November 18, 1998 Regulatory class: II 21 CFR 892.1750/Procode: 90 JAK

Dear Mr. Stanek:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to 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). 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 either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (OS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

This letter will allow you to begin marketing your device as described in your 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 Part 801 and additionally 809.10 for in vitm diagnostic devices), please contact the Office of Compliance at (301) 594-4613. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, piense note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address "https://www.fda.gov/cdr/dsmardsmamain.html".

Sincerely yours,

Lillian Yin, Ph.D.

Director, Division of Reproductiv Abdominal, Ear, Nose and Thro and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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ATTACHMENT 9

INDICATIONS FOR USE

510(k) Number (if known):	K982536
Device Name:	Perfusion CT Software Package

Indications for Use:

Perfusion CT is an application software package that permits cerebral perfusion imaging based on dynamic CT images continuously acquired after the injection of contrast. The package allows visualization of apparent blood flow in brain tissue and pictorially illustrates perfusion related parameters (i.e. relative cerebral blood flow, rclative cerebral blood volume, time to peak). By generating images of cerebral blood flow (CBF), cerebral blood volume (CBV), and local bolus timing (i.e. time to peak) from one set of dynamic CT images, Perfusion CT aids the physician in the assessment of the type and extent of cerebral perfusion disturbances. The software package also allows the calculation of mirrored regions of interest and the visual inspection of time density curves.

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Concurrence of the CDRH, Office of Device Evaluation (ODE)

Prescription Use
OR Over-The-Counter Use
	(Per 21 CFR 801.109)

(Division Sign-Off)

Division of Reproductive, Abdominal, ENT,

and Radiological Devices

510(k) Number	K982536
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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.