The Medrad Quadrature CTL Coil is a receive only coil intended to be used with the General Electric Superconducting MRI Scanners. This coil is intended to facilitate complete MR imaging of the cervical, thoracic and lumbar regions of the spine without need of patient repositioning of the device.

The Medrad Quad CTL Array Coil is intended for use only under the supervision of a Physician trained in the use of Diagnostic Magnetic Resonance Imaging.

Device Description

The Medrad Quad CTL Array Coil is a receive only coil designed to enhance the MR Imaging of the thoracic and lumbar regions of the spine anatomy.

AI/ML Overview

The provided document describes a 510(k) premarket notification for the Medrad Quadrature CTL Array Coil, a receive-only coil designed for MRI imaging of the spine. The evaluation focuses on demonstrating substantial equivalence to predicate devices rather than proving specific performance against predefined acceptance criteria for a new clinical indication or algorithm. Therefore, many standard elements of an AI/algorithm acceptance study are not applicable or explicitly mentioned.

Here's an analysis of the available information:

1. Table of Acceptance Criteria and Reported Device Performance

Formal, quantifiable acceptance criteria (e.g., sensitivity, specificity, accuracy thresholds) are not defined in this 510(k) submission. The performance evaluation is primarily comparative and qualitative, focusing on physical and image quality characteristics relevant to an MRI coil.

Performance Parameter	Acceptance Criteria (Implied/Compared)	Reported Device Performance
Signal to Noise Ratio (SNR)	Comparable to predicate devices, or sufficient for intended diagnostic use (not explicitly quantified).	An SNR study was conducted to generate the SNR of the proposed Medrad 1.0T QUADRATURE CTL ARRAY Coil. Direct comparison to predicate devices was not possible due to different platforms.
Image Uniformity	Meets NEMA Standards for non-uniformity.	The Medrad Quad CTL Array Coil was evaluated using NEMA Standards to characterize the non-uniformity. Contours of axial and sagittal images were constructed. (Implies it met NEMA standards as no non-compliance is reported).
Geometric Distortion	None observable.	None. "No observable distortion of the static magnetic field is present." (This device contains slightly magnetic materials, but their placement prevents distortion.)
Transmit RF Field [B1] Distortion	No artifacts observed; no significant induced currents.	"No artifacts of any type were observed during imaging." (Analysis of electrical design showed no significant currents are induced.)
Resolution, Slice Thickness, Contrast	Not affected by surface coil.	"These performance parameters are not affected by the use of a surface coil and were not separately tested..."
Clinical Effectiveness	Produces similar clinical image results to predicate devices.	"Clinical images for the proposed 1.0T Quad CTL Array Coil have been provided... to demonstrate the clinical effectiveness." "Based on these results, and the SNR results... Medrad concludes that the 0.5T and 1.0T Quad CTL Array Coils will produce similar clinical image results."
Safety and Durability	Demonstrated in predicate devices, and implied for the proposed device through substantial equivalence claim and material comparison (housing, comfort pad).	Extensively conducted on predicate devices (K954952, K902663, K960901). The proposed device's materials were compared to predicates.

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

Test Set Sample Size: Not explicitly stated. The "Clinical Evaluation" mentions "Clinical images" were provided, implying a small set of images, but the number of patients or images is not quantified.
Data Provenance: Not specified. It's likely prospective data for the clinical evaluation, as the intent is to showcase the new device. The country of origin is not mentioned but assumed to be the United States, given the FDA submission.

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

This information is not provided. The clinical evaluation seems to rely on the general "clinical effectiveness" demonstrated by the provided images, likely assessed by the manufacturer's internal team, but no details on expert review or ground truth establishment are given.

4. Adjudication Method for the Test Set

This information is not provided. Given the nature of an MRI coil and the 510(k) submission, formal adjudication methods like 2+1 or 3+1 for diagnostic accuracy are typically not relevant here. The "clinical evaluation" would likely involve visual assessment for image quality and utility.

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

No, an MRMC comparative effectiveness study was not done. The study conducted was primarily a technical and basic image quality assessment of the device itself, leading to a claim of substantial equivalence. The document does not describe human reader performance or improvements with or without AI assistance, as this is an MRI coil, not an AI diagnostic algorithm.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done

Yes, in essence. The "Performance Test Data" section describes evaluations of the coil itself (SNR, image uniformity, geometric distortion, B1 distortion) without human interpretation as part of the primary test. The "Clinical Evaluation" section then presents images, which are inherently "standalone" output of the device, for visual assessment of "clinical effectiveness."

7. The Type of Ground Truth Used

The ground truth for the performance test data is based on physical measurements and NEMA standards (for SNR and image uniformity). For "clinical effectiveness," it's based on the visual assessment of images produced by the coil, implicitly compared to expected clinical image quality from existing devices. There's no mention of pathology or outcomes data being used as ground truth for a diagnostic claim.

8. The Sample Size for the Training Set

This information is not applicable as this is not an AI/machine learning algorithm. The coil design and testing do not involve a "training set" in that context.

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

This information is not applicable as there is no training set for this medical device.

Summary

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K 98 4159

JAN 1 2 1999

510(k) SUMMARY MEDRAD 0.5T, 1.0T QUAD CTL COILS

OFFICIAL CONTACT:	Jim Ferguson, Jr.Sr. Regulatory Affairs AssociateMedrad. Inc.One Medrad DriveIndianola, PA 15051(412) 767-2400 Ext. 3326
CLASSIFICATION NAME:	Magnetic Resonance Diagnostic Accessory[21 CFR 892.1000}
COMMON/USUAL NAME:	MR Imaging Surface Coil
PROPRIETARY NAME:	Medrad Quadrature CTL Array Coil
PREDICATE DEVICES:	Hitachi Quad C-SpineGeneral Electric (GE) Quad T/L with PositionerCoilMedrad Phased Array Shoulder Coil

DEVICE DESCRIPTION:

The Medrad Quad CTL Array Coil is a receive only coil designed to enhance the MR Imaging of the thoracic and lumbar regions of the spine anatomy.

INTENDED USE:

Anatomical Region:	cervical, thoracic and lumbar regions of thespine anatomy.
Nuclei Excited:	Hydrogen
Diagnostic Uses:	2D and 3D Imaging

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Proposed Medrad Quad CTL Coil Technical Comparison To Predicate Devices:

The following table compares claims made in regard to the Hitachi Quad C-Spine Coil and the Medrad Quad CTL Coil.

Hitachi Quad C-SpineCoil (K954952)	GE Quad T/L w/Positioner Coil(K902663)	Medrad PAShoulder Coil(K960901)	Medrad Quad CTL Coil
Receive-only Quadraturecoil	Receive-onlyQuadrature coil	Receive-only,Phased Array Coil	Receive-only, PhasedArray Quadrature coil.
Region of interest includesthe area superior to the topof the sella turcica andinferior to the third thoracicvertebrae. Included is thebrachial plexus region,nerve roots and CSF.	Region of interestincludes the thoracicand lumbar regions ofthe spine.	N/A	Region of interest includesthe cervical, thoracic, andlumbar regions of thespine.
The Quad C-Spine Coil iscompatible with the MRH-1500 and Stratis systempulse sequences andimaging options.	The quad T/L w/Positioner coil iscompatible with allSigna and ContourSystem pulsesequences andappropriate imagingoptions.	The PA Shoulder coilis compatible with allSigna System pulsesequences andappropriate imagingoptions.	The quad CTL coil iscompatible with all Signaand Contour System pulsesequences andappropriate imagingoptions.
No external tuning, ormatching, is necessarysince the coil is matched tothe recommended anatomyof interest.	No external tuning, ormatching, is necessarysince the coil ismatched to therecommended anatomyof interest.	No external tuning,or matching, isnecessary since thecoil is matched to therecommendedanatomy of interest.	No external tuning, ormatching, is necessarysince the coil is matchedto the recommendedanatomy of interest.
The coil plugs into thesystem via three BNCconnectors	The coil plugs into acommon slip connector.	The coil uses aBendix connector forthe MRI Scannerinterface.	The coil uses a Bendixconnector for the MRIScanner interface.

Proposed Medrad Quad CTL Coil Technical Comparison to Predicate Devices (Cont.):

Patient contacting materials comparison information
Hitachi Quad C-Spine Coil	GE Quad T/L w/ Positioner CoilMedrad PA Shoulder Coil	Medrad Quad CTL Coil
The housing material is madefrom Royalite ABS, Fire RatedUL94V-0	The housing material is made fromRoyalite ABS, Fire Rated UL94V-0	The housing material is madefrom Polyurethane 30% GlassFilled, Fire Rated UL 94.5V
Comfort pad material is madeof Unifoam S82N, Fire RatedUL 94 HF-1 with a PVC Filmvinyl film fire rated cover.	Comfort pad material is made ofRecticel Foam (6 lb. density, Fire RatedUL 94V HF1 with a PVC Film vinyl orNylon fire rated cover.	Comfort pad material is madeof Unifoam S82N, Fire RatedUL 94 HF-1 with a Nylon cover,Fire Rated CPAI-84.

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PERFORMANCE TEST DATA:

SIGNAL TO NOISE RATIO (SNR) - A Signal to Noise Ratio(SNR) study was conducted to generate a Signal -To-Noise ratio of the proposed Medrad 1.0T QUADRATURE CTL ARRAY Coil. Due to the different platforms of the predicated devices, a direct comparison between the proposed device and the predicate devices could not be completed.

IMAGE UNIFORMITY - The Medrad Quad CTL Array Coil was evaluated using NEMA Standards to characterize the non-uniformity of the proposed coil. Contours of the images obtained with the coil were constructed for the axial image, sagittal image.

GEOMETRIC DISTORTION: None. Static magnetic field distortion results from the use of magnetic materials in the construction of a surface coil. This device contains slightly magnetic materials or components. However, such components have been positioned within the surface coil so that no observable distortion of the static magnetic field is present.

TRANSMIT RF FIELD [B1] DISTORTION - Analysis of the electrical design of the coil and its blocking network demonstrates that no significant currents are induced. No artifacts of any type were observed during imaging.

RESOLUTION, SLICE THICKNESS, AND CONTRAST - These performance parameters are not affected by the use of a surface coil and were not separately tested in the performance evaluation of the proposed Medrad Quad CTL Array Coil.

CLINICAL EVALUATION - Clinical images for the proposed 1.0T Quad CTL Array Coil have been provided with this submission to demonstrate the clinical effectiveness of the Quad CTL Array coils. Based on these results, and the SNR results for the proposed 1.0T Quad CTL Array Coils, Medrad concludes that the 0.5T and 1.0T Quad CTL Array Coils will produce similar clinical image results.

CONCLUSION - Extensive safety, verification, durability and clinical testing was conducted on the predicate GE and/or Hitachi devices. (K954952, K902663 and K960901) The proposed device is deemed by Medrad to be substantially equivalent.

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Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

JAN 1 2 1999

Jim Ferguson, Jr. Sr. Regulatory Affairs Associate Medrad, Inc. One Medrad Drive Indianola, PA 15051

Re:

K984159

Medrad Quadrature CTL Array Coil Dated: November 18, 1998 Received: November 19, 1998 Regulatory class: II 21 CFR 892.1000/Procode: 90 MOS

Dear Mr. Ferguson:

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 (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 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 requlatory 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) 594-4613. 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/dsma/dsmamain.html".

Sincerely yours,

Capt. Daniel G. Schultz, M.D. Acting Director, Division of Reproductive, Abdominal, Ear, Nose and Throat, and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

Image /page/3/Picture/15 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is an abstract image of a stylized eagle or bird-like figure.

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510 (k) NUMBER (IF KNOWN): K 98 4159

Medrad Quad CTL Array Coil DEVICE NAME:

INDICATIONS FOR USE:

The Medrad Quad CTL Array Coil is a receive only coil intended to be used MRI I he Mediad Quad CTC Anay Coll is a receive and lumbar regions of the spinc anatomy.

The Medrad Quad CTI. Array Coil is intended for use only under the supervision of a The Median Quate Of Prefined of Diagnostic Magnetic Resonance Innaging.

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

	Concurrence of CDRH, Office of Device Evaluation (ODE)
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Prescription Use __________ OR Over-The Counter-Use __________

(Per 21 CFR 801.109) (Optional Format 1-2-96)

	(Division Sign-Off)
	Division of Reproductive, Abdominal, ENT, and Radiological Devices
510(k) Number	K984159

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.