The device is a diagnostic imaging system for fixed or mobile installations that combines Positron Emission Tomography (PET) and X-ray Computed Tomography (CT) systems. The CT subsystem produces cross-sectional images of the body by computer reconstruction of x-ray transmission data. The PET subsystem produces images of the distribution of PET radiopharmaceuticals in the patient body (specific radiopharmaceuticals are used for whole body, head, heart and other organ imaging). Attenuation correction is accomplished by CTAC. The device also provides for list mode, dynamic, and gated acquisitions.

Image processing and display workstations provide software applications to process, analyze, display, quantify and interpret medical images/data. The PET and CT images may be registered and displayed in a "fused" (overlaid in the same spatial orientation) format to provide combined metabolic and anatomical data at different angles. Trained professionals use the images in:

The evaluation, detection and diagnosis of lesions, disease and organ function such as but not limited to cancer, cardiovascular disease, and neurological disorders.
The detection, localization, and staging of tumors and diagnosing cancer patients.
Treatment planning and interventional radiology procedures.

Cardiac imaging software provides functionality for the quantification of cardiology images and datasets including but not limited to myocardial perfusion for the display of wall motion and quantification of left-ventricular function parameters from gated myocardial perfusion studies and for the 3D alignment of coronary artery images from CT coronary angiography onto the myocardium.

Both subsystems (PET and CT) can also be operated independently as fully functional, diagnostic imaging systems including application of the CT scanner as a radiation therapy simulation scanner.

Device Description

The device is a hybrid diagnostic imaging system that combines Positron Emission Tomography (PET) and X-ray Computed Tomography (CT) scanners that can be utilized in fixed installations or mobile environments. The device is comprised of the following system components/subsystems: Positron Emission Tomography (PET), X-ray Computed Tomography (CT), a patient table, gantry separation unit, and the acquisition and processing workstations.

AI/ML Overview

The provided 510(k) summary (K051170) is for the Philips Medical Systems Gemini GXL, a hybrid PET/CT imaging system. However, it does not contain explicit acceptance criteria or a detailed study description with specific performance metrics such as sensitivity, specificity, or accuracy for diagnosing disease.

Instead, the submission focuses on demonstrating substantial equivalence to predicate devices based on safety, intended use, technological comparison, and compliance with recognized industry standards. The "study" mentioned is primarily a verification of compliance with these standards, not a comparative clinical performance study in the way modern AI/CAD device submissions typically require.

Here's an attempt to answer your questions based on the available information, noting where information is absent:

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria (Inferred from regulatory context)	Reported Device Performance (from K051170)
Safety: Compliance with Ionizing Radiation Emitting Products standards (21 CFR 1020.30 & 1020.33) and Electrical/Mechanical safety (IEC 60601-1 series).	Device adheres to recognized and established industry practice. Radiation safety assured by compliance and certification to 21 CFR 1020.30 & 1020.33. Electrical and mechanical safety assured by adherence and certification to IEC 60601-1 series.
Performance: Measurement in accordance with NEMA NU-2 standard for PET performance.	Device performance was measured in accordance with the NEMA-NU2 standard.
Substantial Equivalence: Similar intended use, technological characteristics, and system performance as predicate devices (`Philips Plus` CT Scanner (K0333326) and `Gemini System` (K042935)).	The device is substantially equivalent to the predicate devices based upon similar intended use, technological comparison, and system performance. Key differences noted: option for a 64-slice CT subsystem, and addition of Syntermed NeuroO Software Application.

2. Sample Size for Test Set and Data Provenance

Sample Size: Not explicitly stated in terms of patient or image data for clinical performance evaluation. The "test" mentioned refers to engineering and radiation safety performance testing.
Data Provenance: Not applicable in the context of clinical data performance testing as described in the summary. The performance tests would have been conducted internally by Philips Medical Systems.

3. Number of Experts Used to Establish Ground Truth and Qualifications

Not Applicable. The submission does not detail a study involving expert readers establishing ground truth for diagnostic accuracy, as it's primarily about demonstrating safety and technical performance standards.

4. Adjudication Method for the Test Set

Not Applicable. No clinical test set with adjudicated ground truth is described.

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

No. This type of study was not conducted or reported in this 510(k) summary. The device pre-dates the widespread use of AI/CAD for which such studies are now common. The Syntermed NeuroO Software Application is mentioned, but its performance metrics or a human-in-the-loop study with it are not provided.

6. Standalone (Algorithm Only) Performance Study

No. A standalone algorithm performance study as understood for AI/CAD devices was not reported. The "device" itself is the imaging system, not a specific autonomous algorithm for diagnosis.

7. Type of Ground Truth Used

Not Applicable (for clinical performance). For the technical performance aspects, the "ground truth" would be established by physical measurements and adherence to engineering specifications and regulatory standards (e.g., NEMA NU-2 protocols). There's no clinical ground truth (like pathology or outcomes) reported for diagnostic accuracy.

8. Sample Size for the Training Set

Not Applicable. This submission is for an imaging device, not a machine learning model requiring a specific training set of clinical images.

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

Not Applicable. (See point 8)

Summary of Device and Approval Context:

This 510(k) (K051170) is from 2005 for a PET/CT scanner. At that time, 510(k) clearances for imaging devices primarily focused on demonstrating safety (radiation, electrical, mechanical) and technical performance (e.g., image quality metrics defined by standards like NEMA NU-2) against established predicate devices. The "study" mentioned is a verification of compliance with these engineering and regulatory standards. It is not a clinical study designed to measure diagnostic accuracy (sensitivity, specificity, AUC) against a clinical ground truth, which is a common requirement for AI/CAD devices today. The mention of Syntermed NeuroO Software Application hints at post-processing capabilities, but its clinical performance is not detailed in this premarket notification.

Summary

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K051170

510(k) SUMMARY OF SAFETY AND EFFECTIVENESS

General Information

MAY 2 3 2005

A.	Submitter/ Contact Person:		Rae Ann Farrow
	Philips Medical Systems (Cleveland), Inc.595 Miner Rd.Cleveland, OH 44143		Tel:	(440) 483-2647
			Fax:	(440) 483-7339
B.	Device Trade Name:	Gemini GXL
	Common Name:	Positron Emission TomographyComputed Tomography X-Ray
	Classification Name:	System, Emission Computed Tomography, (892.1200)System, Computed Tomography X-Ray, (892.1750)
	Device Class:	21CFR 892.1200, Class II21 CFR 892.1750, Class II
	Product Code:	90 KPS and 90 JAK
	Classification Panel:	Radiology
C.	Date prepared:	April 8, 2005

(K042935) Gemini System D. Predicate Device: "Philips Plus" CT Scanner (K0333326)

Performance Standards: E.

21 CFR 1020.30 1020.33 Performance Standards for Ionizing Radiation . Emitting Products, Computed Tomography Equipment (Applicable Sections)
. NEMA NU-2

F. Intended Use:

Section X .- 1

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o The evaluation, detection and diagnosis of lesions, disease and organ function such as but not limited to cancer, cardiovascular disease, and neurological disorders.
· The detection, localization, and staging of tumors and diagnosing cancer patients.
· Treatment planning and interventional radiology procedures.

Both subsystems (PET and CT) can also be operated independently as fully functional, diagnostic imaging systems including application of the CT scanner as a radiation therapy simulation scanner.

G. Device Description/ Comparison with Predicate Device:

H. System Performance Test/ Summary of Studies:

To minimize electrical, mechanical and radiation hazards, Philips Medical System adheres to recognized and established industry practice. Radiation safety is assured by compliance and certification to the performance standards for ionizing radiation cmitting product, 21CFR 1020.30 and 21CFR 1020.33. The radiation safety product report will be filed in accordance with 21CFR 1002.10 with the Center for Device and Radiological Health. Electrical and mechanical safety is assured by adherence and certification to the applicable standards in the TEC 60601-1 series. The device performance was measured in accordance with the NEMA-NU2 standard.

I. Comparison to Predicate Devices:

The basic differences in the system include the following:

. The option a 64-slice CT subsystem.
Addition of Syntermed NeuroO Software Application .

In conclusion, the device is substantially equivalent to the predicate devices based upon similar intended use, technological comparison, and system performance.

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Image /page/2/Picture/2 description: The image shows a circular logo with text around the perimeter and a stylized bird-like figure in the center. The text around the circle appears to be the name of a department or organization. The bird-like figure is composed of three curved lines that suggest movement or flight. The logo is black and white and has a simple, clean design.

MAY 2 3 2005

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Philips Medical Systems c/o Morten Simon Christensen Underwriters Laboratories, Inc. 1655 Scott Blvd. SANTA CLARA CA 95050-4169

Re: K051170

Trade/Device Name: Gemini GXL Regulation Number: 21 CFR §892.1200 Regulation Name: Emission computed tomography system Product Code: KPS Regulation Number: 21 CFR §892.1750 Regulation Name: Computed tomography x-ray system Product Code: JAK Regulatory Class: II Dated: May 5, 2005 Received: May 6, 2005

Dear Mr. Christensen:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced we have leveleved your becared by the promised in the indications for use stated in above and have decommised at predicate devices marketed in interstate commerce prior to the closere) to rogally matterial property many of the Medical Devices that have been May 20, 1770, dic claculture and of the Federal Food, Drug, and Cosmetic Act (Act) that reclassition in accordation market approval application (PMA). You may, therefore, market the do not require approval of a provisions of the Act. The general controls provisions of the Act device, subject to the general volusion, 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 If your device is classified (360 able additional controls. Existing major regulations affecting your Apploval), it they of subject of aderal Regulations, Title 21, Parts 800 to 898. 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 that Please be advised that I DA's issualled of a vith other requirements of the Act or any FDA has made a decemination adaly other Federal agencies. You must comply with all the Federal Statues and regulations actimation to registration and listing (21 CFR Part 807); labeling ACL S requirements, modulity, but not a more a cause entrements as set forth in the quality systems (QS) (21 CFR Part 801); good manufacturing product radiation control product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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This letter will allow you to begin marketing your device as described in your Section 510(k)
10 leadly This letter will anow you to ocgin marketing your antial equivalence of your device to a legally premarket notitication. The FDA tinding of Sabstantial of Color States of Sales of Court device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), pleased
ation with advice for your a 1 - 1 - 1 - 1 - 1 - 1 - 1 - 1 - 1 - 1 - 1 -If you desire specific advice for your device on our lasening organisation number at the top of this letter:

21 CFR 876.xxxx	(Gastroenterology/Renal/Urology)	240-276-0115
21 CFR 884.xxxx	(Obstetrics/Gynecology)	240-276-0115
21 CFR 892.xxxx	(Radiology)	240-276-0120
Other		240-276-0100

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Also, please note the regulation entitled, "Frisonalians on your responsibilities under the Act from the 180 807.97). You may onliner general international and Consumer Assistance at its toll-free number (800) Drvision of Small Manufacturers, International and Solaration
638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsmaldsmamain.html

Sincerely yours,

Nancy C. brogdon

Nancy C. Brogdon Director, Division of Reproductive, Abdominal, and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known): Not-Known):

K051170

Device Name: Gemini GXL

Indications for Use:

The device is a diagnostic imaging system for fixed or mobile installations that combines Positron Emission The device is a ulagioste maging with to mography (CT) systems. The CT subsytem produces coss-Tomography (FET) and X-lay Computer reconstruction of x-ray transmission data. The PET subsystem sectional miages of the distribution of PET radiopharmaceuticals in the patient body (specific produces " the used for whole body, head, heart and other organ imaging). Attenuation correction is accomplished by CTAC. The device also provides for list mode, dynamic, and gated acquisitions.

Image processing and display workstations provide software applications to process, analyze, display, quantify mage processing and display wonomicals pro and CT images may be registered and displayed in a "fused" and intelpret medical mages/data. - The TES and Of Mages that of the metabolic and anatomical data at different angles. Trained professionals use the images in:

I The evaluation, detection and diagnosis of lesions, disease and organ function such as but not limited to o cancer, cardiovascular disease, and neurological disorders.
The detection, localization, and staging of tumors and diagnosing cancer patients. O
Treatment planning and interventional radiology procedures. O

Cardiac imaging software provides functionality for the quantification of cardiology images and datasets including but not limited to myocardial perfusion for the display of wall motion and quantification of leftventricular function parameters from gated myocardial perfusion studies and for the 3D alignment of coronary artery images from CT coronary angiography onto the myocardium.

Both subsystens (PET and CT) can also be operated independently as fully functional, diagnostic imaging isystems including application of the CT scanner as a radiation therapy simulation scanner.

Prescription Use V 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 Device Evaluation (ODE)

Narsicbrodins

Page of

(Division Sign-Off)
Division of Reproductive, Abdominal,
and Radiological Devices
510(k) Number K051170

Regulation Number and Section

§ 892.1200 Emission computed tomography system.

(a)
Identification. An emission computed tomography system is a device intended to detect the location and distribution of gamma ray- and positron-emitting radionuclides in the body and produce cross-sectional images through computer reconstruction of the data. This generic type of device may include signal analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component parts, and accessories.(b)
Classification. Class II.