K961391 · Toshiba America Mri, Inc. · MOS · Jul 9, 1996 · Radiology
Device Facts
Record ID
K961391
Device Name
FLEXART QD HEAD/NECK COIL
Applicant
Toshiba America Mri, Inc.
Product Code
MOS · Radiology
Decision Date
Jul 9, 1996
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 892.1000
Device Class
Class 2
Indications for Use
General disease and vascular imaging of the head and cervical regions
Device Story
Flexart Head and Neck Coil (MRT-50GP) is a quadrature (QD) receive-only MRI coil accessory; extension of standard cervical collar. Input: RF signals from patient anatomy. Operation: two independent RF loops (rectangular and figure-8) oriented at 90 degrees; impedance matching via varactors; signal amplification via low-noise amplifiers. Active decoupling during transmit via high-impedance parallel resonant traps activated by diodes. Output: RF signals for MRI image reconstruction. Used in clinical MRI suites; operated by MRI technicians/radiologists. Enhances image signal-to-noise ratio for head and cervical region diagnostics.
Clinical Evidence
Bench testing only. Performance metrics provided include signal-to-noise ratio (SNR) for transaxial (73.2), coronal (62.3), and sagittal (61.2) planes within a 10 cm dsv volume. Safety parameters (static field strength 0.5T, RF power deposition 0.256 W/kg) verified against predicate.
Technological Characteristics
Receive-only QD head and neck coil. Materials: printed circuit coil trace board. Sensing: two independent RF loops (rectangular and figure-8) in quadrature. Impedance matching: varactors. Decoupling: high-impedance parallel resonant traps with diodes. Energy: RF magnetic field. Connectivity: standalone MRI accessory.
Indications for Use
Indicated for general disease and vascular imaging of the head and cervical regions in patients requiring MRI diagnostic procedures.
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
Flexart system and standard QD C-Spine Coil (K933018)
Submission Summary (Full Text)
{0}
9 1996
510(k) Summary
K961391
Date: 8 April 1996
Submitter: Toshiba America MRI, Inc.
280 Utah Avenue
South San Francisco, CA 94080
Contact: Steven M. Kay
(714) 730-5000
Classification Name: Magnetic Resonance Device Accessory - QD Head and Neck Coil
Classification: Class II-90LNH, per 21 CFR 892.1000
Common Name: Head and Neck Coil
Proprietary Name: Flexart Head and Neck Coil
Model Name: MRT-50GP
Establishment Registration Number: 2936923
## Applicable Performance Standards:
None, although this device follows the requirements of the current Guidance for the Content and Review of a Magnetic Resonance Diagnostic Device 510(k) Application.
## Substantial Equivalence Summary:
The Flexart™ Head and Neck Coil is essentially a QD (quadrature) extension of the standard receive only Cervical Collar cleared with the Flexart. The extension consists of adding a figure-8 planar loop onto the printed circuit coil trace board, so that there are now two independent RF loops (one rectangular and one figure-8). The RF magnetic fields from the two loops are oriented at 90 degrees with respect to each other (in quadrature).
The two loops are matched in impedance and tuned to the imaging system's center frequency by using varactors and the RF outputs are then amplified with low noise amplifiers. The active decoupling of the coil during transmit is achieved by use of two (one for each loop) high impedance parallel resonant traps which are activated by diodes. These diodes turn on because of the inductively coupled voltage from the transmitter coil's RF magnetic field.
The Flexart Head and Neck Coil does not change the previously cleared safety parameters of the Flexart system and standard QD C-Spine Coil. Manufacturing methods and software verification and validation procedures for the Flexart system and standard QD C-Spine Coil remain unchanged.
AI
{1}
# Safety Parameters
| Maximum Static Field Strength | 0.5Tesla |
| --- | --- |
| Rate of Change of Magnet Field: | 6.97 T/s axial, 10.64 T/s transverse, with T>700 microseconds |
| Radiofrequency Power Deposition: | 0.256 W/kg |
| Acoustic Noise Levels: | 89.5 - 94.5 Typical |
Note: Safety parameters of the Flexart are not changed from those cleared in the MRT-50GP 510(k) K933018.
# Imaging Performance Parameters
1. Specification volume: 10 cm dsv
2. Signal to Noise Ratio (typical):
- Transaxial: 73.2
- Coronal: 62.3
- Sagittal: 61.2
3. Uniformity: Not Applicable
4. Geometric Distortion: Not Applicable
5. Slice profile in the orthogonal planes: Not Applicable
6. Slice thickness: Not Applicable
7. Interslice spacing: Not Applicable
# Indications for Use
General disease and vascular imaging of the head and cervical regions
A2
