The AIRIS II Magnetic Resonance Diagnostic Device with the CTL Phased Array Coil P/N MR-CTL-51 provides for continuous imaging of the cervical, thoracic, and lumbar spine and adjacent anatomies.

The MR system is an imaging device, and is intended to provide the physician with physiological and clinical information. obtained non-invasively and without the use of ionizing radiation. The MR system produces transverse, coronal, sagittal, oblique, and curved cross-sectional images that display the internal structure of the head, body, or extremities. The images produced by the MR system reflect the spatial distribution of protons (hydrogen nuclei) exhibiting magnetic resonance. The NMR properties that determine the image appearance are proton density, spin-lattice relaxation time (T1), spin-spin relaxation time (T2), and flow. When interpreted by a trained physician, these images provide information that can be useful in diagnosis determination.

Aids in the performance of minimally invasive, diagnostic, and therapeutic procedures of the head, body and extremities which may be facilitated by real-time MR guidance. Such procedures must be performed with MRI-compatible instrumentation, as selected and evaluated by the clinical user.

Device Description

The AIRIS II MRI Magnetic Resonance Diagnostic Device is being enhanced by one additional RF Coil (CTL Phased Array Coil) to increase the clinical utility of the AIRIS II in the stationary configuration.

The CTL Phased Array Coil P/N MR-CTL-51 provides for continuous imaging of the cervical, thoracic, and lumbar spine and adjacent anatomies, and utilizes a proprietary multiple receiver coil configuration (8 elements) operating in the phased array mode. The coil operates in three modes: C, T/L, and L. A multi-position switch is used to select between the modes, by routing a current through PIN diode-activated high impedance tanks.

The C-spine section of the coil is nearly identical in design to the USAI QD C-spine coil P/N MR-QCS-51, and features a removable nosepiece bridge. The T/L and L sections are combinations of flat elements in the coil's base and removable loop sections, connecting to mounting blocks at the edge of the coil.

AIRIS II software did not need to be revised in order to support full functionality of this CTL Phased Array Coil.

AI/ML Overview

The provided document, K994378, describes a 510(k) submission for an "Additional RF Coil for AIRIS II (CTL Phased Array)" and does not contain detailed information about acceptance criteria or a specific study proving the device meets acceptance criteria in the manner typically seen for AI/ML-based medical devices.

Instead, this submission is for a hardware enhancement (a new RF coil) for an existing Magnetic Resonance (MR) diagnostic device. The regulatory review process for such a device at the time (late 1990s) focused on demonstrating substantial equivalence to a predicate device, primarily through technical specifications, functional descriptions, and indications for use, rather than extensive performance studies with acceptance criteria as one might expect for a diagnostic or AI-driven software.

Based on the provided text, here's what can be extracted and what information is not present:

Missing Information:

A table of acceptance criteria and reported device performance.
Sample sizes, data provenance, number of experts, adjudication methods, MRMC studies, standalone AI performance, or how ground truth was established for a performance study. These types of studies are not described because this submission is not for a new diagnostic algorithm.

Information Extracted from the Document:

A table of acceptance criteria and the reported device performance:
- This document does not provide a table of acceptance criteria or reported device performance in the context of diagnostic accuracy, sensitivity, or specificity.
- The "performance" described is related to the physical and functional characteristics of the new RF coil and its compatibility with the existing AIRIS II MRI system.
- The submission focuses on demonstrating that the new CTL Phased Array Coil, when added to the AIRIS II, still functions as an MR diagnostic device and provides continuous imaging of the cervical, thoracic, and lumbar spine and adjacent anatomies, similar to the predicate device and the existing AIRIS II capabilities. The performance is implied by its ability to perform these imaging tasks.
Sample size used for the test set and the data provenance:
- Not applicable. This is a hardware modification (RF coil) for an existing MRI system. The document does not describe a "test set" of patient data for evaluating a diagnostic algorithm.
- The "testing" mentioned would be related to engineering validation of the coil's electrical and mechanical performance, and its integration with the MRI system, not clinical diagnostic accuracy based on a patient dataset.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable. This is not a study requiring expert ground truth for diagnostic accuracy.
Adjudication method for the test set:
- Not applicable.
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:
- Not applicable. This is a hardware component for an MRI system, not an AI/ML-based diagnostic aid.
If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Not applicable. This is a hardware component, not a standalone algorithm.
The type of ground truth used:
- Not applicable.
The sample size for the training set:
- Not applicable. This is a hardware component, not an AI/ML system requiring a training set.
How the ground truth for the training set was established:
- Not applicable.

Summary based on the K994378 document:

The K994378 submission for the CTL Phased Array Coil for the AIRIS II MRI system is a 510(k) Pre-market Notification seeking to demonstrate substantial equivalence to a previously cleared device (the Hitachi AIRIS II, K974212 and the USAI QD C-spine coil P/N MR-QCS-51).

The "study" for this type of submission is essentially the demonstration that the new coil performs its intended function (providing continuous imaging of the cervical, thoracic, and lumbar spine and adjacent anatomies) and integrates seamlessly with the existing AIRIS II system without altering its fundamental scientific concepts, physical, or performance characteristics in a way that would raise new questions of safety or effectiveness.

The document implicitly "proves the device meets acceptance criteria" by stating its technological characteristics are "Identical to the Predicate Device" (Section 5.0) and describing its function as an enhancement that "provides for continuous imaging of the cervical, thoracic, and lumbar spine and adjacent anatomies," which aligns with the predicate device's capabilities. The FDA's clearance letter (MAR - 7 2000) confirms that the agency found the device "substantially equivalent" for its stated indications for use, thereby implicitly accepting that it meets the necessary criteria for safe and effective operation as an MRI coil.

Summary

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K994378

Attachment 1

510(k) Summary of Safety and Effectiveness

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SUBMITTER INFORMATION: 1.0

Hitachi Medical Systems America 1.1 Submitter: 1959 Summit Commerce Park Twinsburg, OH 44087 PH: 330 425-1313 FX: 330 425-1410
James Jochen Rogers 1.2 Contact:
1.3 Date: December 21, 1999

DEVICE NAME: 2.0

Radiology 2.1 Classification Panel:
2.2 Classification Number: 892.1000 Magnetic Resonance Diagnostic Device
Product Nomenclature: 2.3 System, Nuclear Magnetic Resonance Imaging
2.4 Product Code(s): 90LNH 90MOS (Magnetic Resonance Specialty Coil)
2.5 Trade/Proprietary Name: AIRIS II
2.6 PREDICATE DEVICE(s):

Hitachi AIRIS II

3.0 DEVICE DESCRIPTION:

3.1 FUNCTION
Identical to the AIRIS II 510(k) K974212.

Imaging Mode	Coil Size
C	One quadrature combination, saddle andsolenoid, identical to current QD -spine
T/L	Two quadrature combinations, one routedthrough the solenoid and saddle inputs ofchannel one, the other consists of one elementcombined in quadrature in the coil with another,this signal subsequently is routed into the saddleinput of channel two
L	One quadrature combination, saddle andsolenoid, and one linear saddle element

A multi-position switch is used to select between the modes, by routing a current through PIN diode-activated high impedance tanks.

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AIRIS II software did not need to be revised in order to support full functionality of this CTL Phased Array Coil.

SCIENTIFIC CONCEPTS 3.2

Magnetic Resonance (MR) is based on the fact that certain atomic nuclei have electromagnetic properties which cause them to act as small spinning bar magnets. The most ubiquitous of these nuclei is hydrogen, which makes it the primary nucleus used in current imaging experiments in magnetic resonance. When placed in a magnetic field, there is a slight net orientation or alignment of these atomic nuclei with the magnetic field. The introduction of a short burst of radiofrequency (RF) excitation of wavelength specific to the magnetic field strength and to the atomic nuclei under consideration can cause a reorientation of the proton's magnetization vector. When the RF excitation is removed, the proton relaxes and returns to its original orientation. The rate of relaxation is exponential, and varies with the character of the proton and its adjacent molecular environment. This reorientation process is characterized by two exponential relaxation times called T1 and T2 which can be measured.

These relaxation events are accompanied by an RF emission or echo which can be measured and used to develop a representation of these emissions on a three dimensional matrix. Spatial localization is encoded into the echo by varying the RF excitation and by appropriately applying magnetic field gradients in x, y, and z directions, and changing the direction and strength of these gradients. Images depicting the spatial distribution of NMR characteristics of the nuclei under consideration can be constructed by using image processing techniques similar to those used in CT.

For magnetic fields up to 1.5T, the RF frequencies commonly used range up to 65MHz. The RF fields have pulse powers from several watts to greater than 10 kilowatts, and repeat at rates from once every few seconds to greater than fifty per second. The timevarying magnetic gradient fields have a typical duration of sub-millisecond to several milliseconds.

PHYSICAL AND PERFORMANCE CHARACTERISTICS 3.3

MR is currently of great interest because it is capable of producing high quality anatomical images without the associated risks of ionizing radiation. In addition, the biological properties that contribute to MR image contrast are different from those responsible for x-ray image contrast. In x-ray imaging, differences in x-ray attenuation, largely based on differences in electro density are responsible for the contrast observed in x-ray images. In MR imaging, differences in proton density, blood flow, and relaxation times T1 and T2 all may contribute to image contrast. In addition, by varying the duration and spacing of the RF pulses, images may be produced in which the contrast is primarily dependent on T1 relaxation, T2 relaxation, proton density, or a combination of all three.

DEVICE INTENDED USE: 4.0

The MR system is an imaging device, and is intended to provide the physician with physiological and clinical information, obtained non-invasively and without the use of ionizing radiation. The MR system produces transverse, coronal, sagittal, oblique, and curved cross-sectional images that display the internal structure of the head, body, or

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extremities. The images produced by the MR system reflect the spatial distribution of protons (hydrogen nuclei) exhibiting magnetic resonance. The NMR properties that determine the image appearance are proton density, spin-lattice relaxation time (T1), spin-spin relaxation time (T2), and flow. When interpreted by a trained physician, these images provide information that can be useful in diagnosis determination.

Head, Body, Spine, Extremities Anatomical Region: ●
Nucleus excited: Proton
Diagnostic uses:

2D T1- / T2-weighted imaging T1, T2, proton density measurements

MR Angiography

image processing

Imaging capabilities:

2D Spin Echo (SE); also with rephase
2D Gradient Field Echo (GE); also with rephase (2D GR)
2D Steady state acquisition with rewinded GE (SARGE); also with RF spoiling, rephasing
2D Inversion Recovery (IR)
2D Fast Spin Echo (FSE); also with rephase
2D Fast Inversion Recovery (FIR)
2D Dual Slice acquisition (SEDS)
3D Spin Echo (SE)
3D Gradient Field Echo (GE)
3D Steady state acquisition with rewinded GE (SARGE); also with RF spoiling, rephasing
MR Angiography (2D TOF, 3D TOF, half echo, high resolution/high definition, sloped slab profile, magnetization transfer contrast)
MR Fluoroscopy
RF Coil Uniformity
Adaptive Image post-processing
ACR/NEMA/DICOM 3 compliant
Aids in the performance of minimally invasive, diagnostic, and therapeutic procedures of the head, body, and extremities which mav be facilitated by real-time MR guidance. Such procedures must be performed with MRI-compatible instrumentation, as selected and evaluated by the clinical user.

DEVICE TECHNOLOGICAL CHARACTERISTICS: 5.0

Identical to the Predicate Device.

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Public Health Service

Food and Drug Administration

9200 Corporate Boulevard

MAR - 7 2000

James Jochen Rogers Manager, Regulatory Affairs Hitachi Medical Systems America, Inc. 1959 Summit Commerce Park Twinsburg, Ohio 44087

Re:

Rockville MD 20850 K994378 CTL Phased Array Coil for use with AIRIS II Magnetic Resonance Diagnostic Device Dated: December 21, 1999 Received: December 27, 1999 Regulatory class: II 21 CFR 892.1000/Procode: 90 MOS

Dear Mr. Rogers:

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 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). 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 (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 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 vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4591. 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 requiation entitled, "Misbranding by reference to premarket notification" (21CFR 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/dsma/dsmamain.html".

Sincerely yours,

Daniel G. Schultz, M.D. Captain, USPHS Acting Director, Division of Reproductive, Abdominal, and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure(s)

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1994278 510(k) Number (if known): __

Device Name: Additional RF Coil for AIRIS II (CTL Phased Array)

Indications for Use:

The AIRIS II Magnetic Resonance Diagnostic Device with the CTL Phased Array Coil P/N MR-CTL-51 provides for continuous imaging of the cervical, thoracic, and lumbar spine and adjacent anatomies.

Anatomical Region: Head, Body, Spine, Extremities
- Nucleus excited:
Diagnostic uses:

Proton 2D T1- / T2-weighted imaging T1, T2, proton density measurements MR Angiography image processing

Imaging capabilities:
2D. 3D Spin Echo (SE)
2D, 3D Fast Spin Echo (FSE)
2D Inversion Recovery (IR)
2D, 3D Fast Inversion Recovery (FIR)
2D.3D Gradient Echo (GE)
2D, 3D Steady state acquisition with rewinded GE (SARGE)
2D. 3D RF-spoiled SARGE (RSSG)
2D, 3D Time-reversed SARGE (TRSG)
MR Angiography (half echo, high resolution/high definition, sloped slab profile, magnetization transfer contrast) 2D, 3D TOF
- 2D, 3D TOF RSSG
ECG, Peripheral Gating
RF Coil Uniformity

Adaptive Image post-processing

ACR/NEMA/DICOM 3 compliant

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use (Per 21 CFR 801-109

Vinid C. Seymour
OR

Division Sion-Off) ctive, Abdominal, ENT. 510(k) Numbe

Over-the-Counter Use _

(Optional Format 1-2-96)

Regulation Number and Section

§ 892.1000 Magnetic resonance diagnostic device.

(a)
Identification. A magnetic resonance diagnostic device is intended for general diagnostic use to present images which reflect the spatial distribution and/or magnetic resonance spectra which reflect frequency and distribution of nuclei exhibiting nuclear magnetic resonance. Other physical parameters derived from the images and/or spectra may also be produced. The device includes hydrogen-1 (proton) imaging, sodium-23 imaging, hydrogen-1 spectroscopy, phosphorus-31 spectroscopy, and chemical shift imaging (preserving simultaneous frequency and spatial information).(b)
Classification. Class II (special controls). A magnetic resonance imaging disposable kit intended for use with a magnetic resonance diagnostic device only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.