The intended use of the device here in question, i.e., the Imatron Ultrafast CT Scanner, remains unchanged from the intended use of prior predicate Imatron and other scanners. The Imatron Ultrafast CT Scanner is designed -- as are all similar devices -- to produce cross sectional images (i.e., thin slices) of the human anatomy. In this instance, such images are produced via helical (i.e., continuous volume or dynamic) or stationary (i.e., static) scanning. Imatron's device is -- as are some of the predicate devices -- also intended to be used for clinical situations requiring determination of specific quantitative information, such as the determination of calcium or other materials in bone, tumors, or organs.

Device Description

The Imatron Ultrafast CT scanner is a scanning system which operates by directing a focused beam of electrons along tungsten target rings to produce X-rays which pass through the body at multiple angles as in conventional CT scanning systems. The Imatron Ultrafast CT scanner is capable of producing CT slices at rapid speeds since the data is produced by electronic rotation of the electron beam itself rather than the mechanical rotation of an X-ray tube as in conventional CT scanning systems. Currently, the Imatron Ultrafast CT scanner operating at its highest resolution mode has 864 single, contiguous X-ray detectors subtending an arc of 0.250 degrees each. The resulting 5% amplitude modulation transfer function (MTF) for high contrast objects at the center of the circle of reconstruction is 7 line pairs per centimeter (lp/cm).

AI/ML Overview

The provided text describes a 510(k) submission for a design modification to the Imatron Ultrafast CT Scanner, specifically implementing a High Resolution Detector (HRD). The study focuses on demonstrating "substantial equivalence" to a predicate device rather than establishing new acceptance criteria for a novel device. Therefore, some information requested, particularly regarding acceptance criteria and separate performance metrics, is not explicitly detailed as would be for a new device submission.

Here's an analysis of the available information:

1. Table of Acceptance Criteria and Reported Device Performance

The submission doesn't present a formal table of "acceptance criteria" in the sense of predefined thresholds for clinical performance metrics (e.g., sensitivity, specificity). Instead, it focuses on demonstrating that the modified device's performance, specifically its image resolution, is improved and that the device remains "substantially equivalent" to its predicate.

Criterion/Parameter (as described)	Predicate Device Performance	Modified Device (HRD) Performance	Acceptance (Implied)
Arc Subtended by Detectors	0.250 degrees (864 single detectors)	0.125 degrees (864 pairs of detectors)	Improved Resolution
5% Amplitude MTF (High Contrast Objects, center of reconstruction)	7 line pairs per centimeter (lp/cm)	9.5 lp/cm	Improved Resolution (Superior to Predicate)
Dose Efficiency	Original system's	Retained (same as original)	Equivalent
Number of Data Acquisition Channels	Original system's	Retained (same as original)	Equivalent
Number of Samples	Original system's	Retained (same as original)	Equivalent
Safety, Effectiveness, Intended Use Impact	Not significantly impacted by other modifications	Not significantly impacted	Equivalent

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

Test Set Sample Size: 12 human subjects.
Data Provenance: Clinical performance testing with human volunteers was conducted "on site" (likely Imatron's facility) and was prospective, following IRB overview and informed consent. The country of origin is not explicitly stated but can be inferred as the USA given the FDA submission context.

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

This information is not provided in the document. The study described is a "human volunteer testing" to show "substantial equivalence," not a diagnostic accuracy study requiring expert-derived ground truth for the device's output.

4. Adjudication Method for the Test Set

This information is not provided. As noted above, the study appears to be focused on demonstrating device functionality and equivalence, not a diagnostic accuracy study that would typically involve adjudication of device outputs against a ground truth.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done

No, an MRMC comparative effectiveness study was not done. The submission describes bench testing and human volunteer testing to demonstrate substantial equivalence of the device itself, not to evaluate reader performance with or without AI assistance. The device in question is a CT scanner, not an AI software.

6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done

Yes, in a sense. The "Non-clinical Performance" section describes extensive bench testing (~61 tests including product acceptance and release criteria, and phantom testing) carried out before human testing. This represents a standalone assessment of the device's physical and technical performance. The device itself is a scanner, not an AI algorithm, so the concept of an "algorithm only" performance would refer to its technical specifications.

7. The Type of Ground Truth Used

For the bench testing and phantom testing, the "ground truth" would be established by the physical characteristics of the phantoms and the expected technical performance measurements for a CT scanner (e.g., MTF calculations). For the human volunteer testing, the "ground truth" or reference standard for comparison is the performance characteristics of the predicate device, aiming to show that the modified device performs equivalently or better in terms of image quality and safety. There is no mention of pathology, outcomes data, or expert consensus in relation to diagnostic accuracy for clinical conditions.

8. The Sample Size for the Training Set

This information is not applicable and therefore not provided. The Imatron Ultrafast CT Scanner is a hardware device (a CT scanner), not a machine learning or AI-based algorithm that requires a "training set" in the context of AI development.

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

This information is not applicable as there is no training set for a hardware device.

Summary

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Image /page/0/Picture/0 description: The image shows the word "IMATRON" in a stylized, bold font. The letters are formed by horizontal lines, giving them a futuristic or technical appearance. To the right of the word, there is a small "TM" symbol, indicating a trademark. Below the word, there is a dotted line that extends diagonally downwards.

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11972879

1 5 1997 OCT

510(K) SUMMARY
Submitter's Name:	Imatron, Inc.
Address:	389 Oyster Point Blvd.South San Francisco, CA 94087
Phone(s):	(O) 415-583-9964, ext. 206(F) 415-827-7790
Contact Person:	J.A. Coduto
Date:	August 1, 1997
Common Names:	CT Scanner; Computed Tomography X-ray System
Proprietary Names:	Ultrafast® CT Scanner; EBT CT Scanner, Evolution
Classification Name:	Computed Tomography X-ray System
Predicate Device:	Imatron Ultrafast CT Scanner (K913352/A)
Device Description:	The Imatron Ultrafast CT scanner is a scanningsystem which operates by directing a focused beamof electrons along tungsten target rings to produceX-rays which pass through the body at multipleangles as in conventional CT scanning systems.
	The Imatron Ultrafast CT scanner is capable ofproducing CT slices at rapid speeds since the datais produced by electronic rotation of the electronbeam itself rather than the mechanical rotation ofan X-ray tube as in conventional CT scanningsystems.
	Currently, the Imatron Ultrafast CT scanneroperating at its highest resolution mode has 864single, contiguous X-ray detectors subtending anarc of 0.250 degrees each. The resulting 5%amplitude modulation transfer function (MTF) forhigh contrast objects at the center of the circle ofreconstruction is 7 line pairs per centimeter (lp/cm).

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Proposed Design Modification

The primary purpose of this submission is to provide notification of a proposed design modification to the above-referenced detector system. This modification, in the aggregate, is called the High Resolution Detector (HRD). Similar to the current system, the HRD retains the original dose efficiency, the same number of data acquisition channels, and the same number of samples. It differs from the current system in that it now consists of 864 pairs of contiguous detectors subtending an arc 0.125 degree width. In the modified system odd numbered detector outputs (i.e., one half of each of the 864 pairs) are electronically delayed 60 microseconds, the time required for an object shadow to move one detector's width. This is defined by Imatron as the Time to Next Detector (TND). In the modified system each delayed output is summed with its even numbered, undelayed partner's. The resulting 5% amplitude MTF is 9.5 lp/cm.

Other Modifications

Additionally, this notification also sets forth the numerous, nonsignificant modifications made since Imatron's last 510(k) filing with the Agency (i.e., on July 26, 1991; see K913352/A). As indicated in tables contained herein (and subsequently referenced and discussed), Imatron believes such modifications have not significantly impacted the safety, effectiveness, or intended use of the device. and, thus, they did not need to be the subject of premarket notification.

The intended use of the device here in question. i.e., the Imatron Ultrafast CT Scanner, remains unchanged from the intended use of prior predicate Imatron and other scanners. The Imatron Ultrafast CT Scanner is designed -- as are all similar devices -- to produce cross sectional images (i.e., thin slices) of the human anatomy. In this instance, such images are produced via helical (i.e., continuous

Intended Use:

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volume or dynamic) or stationary (i.e., static) scanning. Imatron's device is -- as are some of the predicate devices -- also intended to be used for clinical situations requiring determination of specific quantitative information, such as the determination of calcium or other materials in bone, tumors, or organs.

See attached Substantial Equivalence Comparison Technological Table and Table of Explanation of Differences. Characteristics:

In order to assure proper product performance, Non-clinical Performance: including reliability, and demonstrate substantial equivalence of the modified scanner here in question to the predicate scanner, the modified scanner was extensively bench tested. Such finished testing included approximately 61 tests to determine conformance with n numerous performance specifications, including four product acceptance tests and 12 product release criteria tests. Also included was phantom testing to assure the requisite quality of the finished X-ray product.

Clinical Performance: After successfully completing bench testing such modified device was then used for human volunteer testing - pursuant to IRB overview and informed consent. Such testing was conducted on site, and incorporated use of twelve human subjects. Again, the device was demonstrated to be substantially equivalent.
- Testing Conclusions: The above-referenced tests indicated that the device as modified is substantially equivalent to the predicate device.

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Image /page/3/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" around the perimeter. Inside the circle is an abstract image of an eagle or bird-like figure with three stylized lines representing its wings or body. The logo is black and white.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

OCT 1 5 1997

J.A. Coduto Director, Regulatory Affairs Imatron, Inc. 389 Oyster Point Blvd. South San Francisco, CA 94080 Re: K972879

Ultrafast Computed Tomography Scanner Models C-150XP and C-150LXP with High Resolution Detector Dated: August 4, 1997 Received: August 5, 1997 Regulatory class: II 21 CFR 892.1750/Procode: 90 JAK

Dear Mr. Coduto:

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, 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 requirement, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, 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 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 vitro 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, please 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 http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours.

h.D.Liau Yu

Lillian Yin, Ph.D. Director, Division of Reproductive, Abdominal, Ear, Nose and Throat, and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health

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D. PROPOSED INTENDED USE STATEMENT

David b. Sijmm

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

Prescription Use
(Per 21 CFR 801.109)

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.