MAGNETIC RESONANCE DIAGNOSTIC DEVICE

K072279 · Hitachi Medical Systems America, Inc. · LNH · Sep 21, 2007 · Radiology

Device Facts

• Record ID: K072279
• Device Name: MAGNETIC RESONANCE DIAGNOSTIC DEVICE
• Applicant: Hitachi Medical Systems America, Inc.
• Product Code: LNH · Radiology
• Decision Date: Sep 21, 2007
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 892.1000
• Device Class: Class 2

Intended Use

The OASIS 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.

Device Story

OASIS is a 1.2 Tesla superconducting open-gantry MRI system. It utilizes hydrogen proton magnetic resonance to generate cross-sectional images (transverse, coronal, sagittal, oblique, curved). Input: RF excitation pulses and magnetic field gradients (x, y, z) applied to patient; Output: measured RF echoes reconstructed into 3D anatomical images. Used in clinical settings by trained physicians/technicians. System processes signals based on proton density, T1/T2 relaxation times, and flow. Output images assist physicians in diagnosis by visualizing internal structures without ionizing radiation. Based on ECHELON MRI architecture.

Clinical Evidence

No clinical data provided; bench testing only.

Technological Characteristics

1.2 Tesla superconducting open magnet; open gantry design. Sensing principle: Magnetic Resonance Imaging (hydrogen proton excitation). Connectivity: Not specified. Software: V1.0A Operating System. Image reconstruction via standard MR processing techniques.

Indications for Use

Indicated for non-invasive imaging of head, body, spine, and extremities in patients requiring diagnostic information via T1, T2, proton density, diffusion-weighted imaging, or MR angiography. Contraindications not specified.

Regulatory Classification

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).

Special Controls

*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.

Predicate Devices

• ECHELON Magnetic Resonance Imaging System (K052172)

Submission Summary (Full Text)

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K072279
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1 2007

## Submitter Information

| Submitter: | Hitachi Medical Systems America, Inc.<br>1959 Summit Commerce Park<br>Twinsburg, Ohio 44080-2371<br>ph: [phone]<br>fax: [phone] | | | SEP 2 |
|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------|--|-------|
| Contact: | Douglas J. Thistlethwaite | | | |
| Date: | 08/13/2007 | | | |
| Device Name | | | | |
| Classification Name: | | System, Nuclear Magnetic Resonance Imaging | | |
| Classification Number: | | 90LNH | | |
| Trade/Proprietary Name: | | OASIS Magnetic Resonance Imaging System | | |
| Predicate Device(s): | | ECHELON Magnetic Resonance Imaging System<br>(K052172) | | |

## Device Intended Use

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.

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## Device Description

### Function

The OASIS is a Magnetic Resonance Imaging System that utilizes a 1.2 Tesla superconducting open magnet in an open gantry design was based on the ECHELON MRI system. The OASIS has been designed to enhance clinical utility as compared to the ECHELON by taking advantage of open architecture.

#### Scientific Concepts

Magnetic Resonance Imaging (MRI) is based on the fact that certain atomic nuclei have electromagnetic properties that cause them to act as small spinning bar magnets. The most ubiquitous of these nuclei is hydrogen, which makes it the primary nuclei currently used in magnetic resonance imaging. When placed in a static magnetic field, these nuclei assume a net orientation or alignment with the magnetic field, referred to as a net magnetization vector. The introduction of a short burst of radiofrequency (RF) excitation of a wavelength specific to the magnetic field strength and to the atomic nuclei under consideration can cause a re-orientation of the net magnetization vector. When the RF excitation is removed, the protons relax and return to their original vector. The rate of relaxation is exponential and varies with the character of the proton and its adjacent molecular environment. This re-orientation process is characterized by two exponential relaxation times, called T1 and T2.

A RF emission or echo that can be measured accompanies these relaxation events. The emissions are used to develop a representation of the relaxation events in a three dimensional matrix. Spatial localization is encoded into the echoes by varying the RF excitation, applying appropriate magnetic field gradients in the x, y, and z directions, and changing the direction and strength of these gradients. Images depicting the spatial distribution of the NMR characteristics can be reconstructed by using image processing techniques similar to those used in computed tomography.

## Physical and Performance Characteristics

MRI is capable of producing high quality anatomical images without the associated risks of ionizing radiation. The biological properties that contribute to MR image contrast are different from those responsible for x-ray image contrast. In MR imaging, difference in proton density, blood flow, and T1 and T2 relaxation times can all contribute to image contrast. By varying the pulse sequence characteristics, the resulting images can emphasize T1, T2, proton density, or the molecular diffusion of water or other proton containing molecules.

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K172279
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# Device Technological Characteristics

The technological characteristics of this device are similar to the primary predicate device. The primary difference is the 1.2 Tesla superconducting open magnet. The control and image processing hardware and the base elements of the system software are identical to the predicate device.

## Conclusions

It is the opinion of Hitachi Medical Systems America, Inc. that OASIS MRI system is substantially equivalent to the listed predicate device. The intended use is identical to the listed predicate device.

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# DEPARTMENT OF HEALTH & HUMAN SERVICES

Food and Drug Administration 9200 Corporate Blvd. Rockville MD 20850

SEP 2 1 2007

Mr. Doug Thistlethwaite Manager, Regulatory Affairs Hitachi Medical Systems America, Inc. 1959 Summit Commerce Park TWINSBURG OH 44087

Re: K072279

Trade/Device Name: OASIS, w/V1.0A Operating System Software Regulation Number: 21 CFR 892.1000 Regulation Name: Magnetic resonance diagnostic device Regulatory Class: II Product Code: LNH Dated: August 13, 2007 Received: August 16, 2007

#### Dear Mr. Thistlethwaite:

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 either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affective your. device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Image /page/3/Picture/9 description: The image shows a circular logo with the text "1906-XXX" at the top. The letters "FDA" are prominently displayed in the center of the logo. Below the letters, the word "Centennial" is written in a smaller font. Three stars are arranged in a horizontal line beneath the word "Centennial."

Promoting and Promoting Public Health

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Page 2 -

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that 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 comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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 Part 801), please contact the Office of Compliance at one of the following numbers, based on the regulation number at the top of this letter:

| 21 CFR 876.xxx | (Gastroenterology/Renal/Urology | 240-276-0115 |
|----------------|---------------------------------|--------------|
| 21 CFR 884.xxx | (Obstetrics/Gynecology). | 240-276-0115 |
| 21 CFR 894.xxx | (Radiology) | 240-276-0120 |
| Other | | 240-276-0100 |

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). 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 [phone] or [phone]

or at its Internet address http://www.fda.gov/cdrl/industry/support/index.litml.

Sincerely yours,

Nancy C. Hogdon

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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#### 510(k) Number (if known): Device Name: OASIS, w/V1.0A Operating System Software

#### Indications for Use:

The OASIS 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.

| Anatomical Region: | Head, Body, Spine, Extremities |
|--------------------|-------------------------------------------------------------------------------------------------------------|
| Nucleus excited: | Proton |
| Diagnostic uses: | T1, T2, proton density weighted imaging<br>Diffusion weighted imaging<br>MR Angiography<br>Image processing |

Prescription Use × AND/OR

Over-the-Counter Use

(21 CFR 801 Subpart C)

(Part 21 CFR 801 Subpart D)

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

Lornim Wh

Radiological De 510(k) Number