Imaging of the whole body (including the head, abdomen, heart, pelvis, spine, blood vessels, limbs and extremities), fluid visualization, 2D/3D Imaging, MR Angiography, MR Fluoroscopy.

Device Description

The MRT-35A v9.0 is a modification of the MRT-35A system which uses a 0.35T superconducting magnet. The MRT-35A v9.0 is an incremental upgrade to an MRT-35A system which is configured with version 8 hardware and software. The 9.0 upgrade replaces the version 8 computer system. The computer architecture, operational characteristics and user software follow the same design considerations cleared by Flexart™ and Visart™ systems. This 9.0 upgrade makes no change to the MRT-35A version 8 series magnet, gradient system or coil set.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study information for the MRT-35A v9.0 device, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria for the MRT-35A v9.0 are implicitly defined by its equivalency to previously cleared devices (MRT-35A v8.0 and Flexart™) and its demonstrated adherence to "consensus standards requirements" for image quality. The performance is reported by comparing key safety and image performance parameters to these predicate devices.

Acceptance Criteria Category	Specific Parameter	Acceptance Criterion (Implicitly based on Predicate Device Performance)	Reported MRT-35A v9.0 Performance
Safety Parameters	Maximum static field strength	0.35 T (MRT-35A v8.0) / 0.5 T (Flexart™)	0.35 T
	Rate of change of magnetic field	6.83 T/sec (MRT-35A v8.0) / 11 T/sec (Flexart™)	6.83 T/sec
	Max. radio frequency power deposition	0.34 W/kg (MRT-35A v8.0) / <0.256 W/kg (Flexart™)	0.3 W/kg
	Acoustic Noise levels	101.6 db (max) (MRT-35A v8.0) / 100.2 db (max) (Flexart™)	110.4 db (max)
Image Performance	Specification Volume: Head	10cm dsv (MRT-35A v8.0) / 10.4cm dsv (Flexart™)	10cm dsv
	Specification Volume: Body	20cm dsv (MRT-35A v8.0) / 10.4cm dsv (Flexart™)	20cm dsv
	Signal-to-Noise ratio	Conformance with consensus standards requirements	Demonstrated conformance
	Uniformity	Conformance with consensus standards requirements	Demonstrated conformance
	Slice Profiles	Conformance with consensus standards requirements	Demonstrated conformance
	Geometric Distortion	Conformance with consensus standards requirements	Demonstrated conformance
	Slice Thickness/Interslice Spacing	Conformance with consensus standards requirements	Demonstrated conformance

2. Sample size used for the test set and the data provenance

The document does not explicitly state the sample size for a test set in terms of clinical cases or patient numbers. It mentions that "Sample phantom images and clinical images were presented for all new sequences." This implies a qualitative assessment rather than a quantitative, numerically defined test set.

The data provenance (country of origin of the data, retrospective or prospective) is not mentioned. Given the nature of a 510(k) submission for a device upgrade, it's likely previous clinical data from the predicate devices or internal testing data were leveraged, but this is not definitively stated.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

The document does not specify the number of experts or their qualifications used to establish ground truth for the test set. The assessment appears to be based on "consensus standards requirements" for image quality, which implies an understanding of established medical imaging quality metrics by the reviewers.

4. Adjudication method for the test set

The document does not describe any specific adjudication method (e.g., 2+1, 3+1) for the test set. The evaluation seems to be based on a comparison to "consensus standards requirements" and visual assessment of "sample phantom images and clinical images."

5. 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

No MRMC comparative effectiveness study is mentioned. This device is an upgrade to an existing MRI system and does not involve AI for interpretation or improvement of human reader performance.

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

This section is not applicable. The device is an MRI system, not an algorithm, and its performance is inherently tied to human operation and interpretation of images.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

The ground truth for image performance appears to be based on "consensus standards requirements" for various image quality metrics (Signal-to-Noise ratio, Uniformity, Slice Profiles, Geometric Distortion, and Slice Thickness/Interslice Spacing). For the clinical images, the implicit ground truth would be the expected visual quality and diagnostic utility that a radiologist would expect from an MRI system. There's no mention of pathology or outcomes data being used for the performance evaluation in this summary.

8. The sample size for the training set

The document does not describe a training set. As this is an upgrade to an MRI system, the "training" would have been the development and optimization of the underlying software and hardware components, rather than a machine learning training set in the modern sense.

9. How the ground truth for the training set was established

Not applicable, as no training set (in the machine learning context) is described. The development of the system's "software technology" and "applications software" would have been guided by established engineering principles and medical imaging requirements, rather than a specific "ground truth" derived for a training set.

Summary

{0}------------------------------------------------

K964608

FEB - 4 1997

510(k) Summary

Magnetic Resonance Device Accessory 1. DEVICE NAME: MRT-35A v9.0 Model Number Trade/Propriety Name: MRT-35A v9.0 ESTABLISHMENT REGISTRATION: 2936923 2. Toshiba America MRI, Inc. 3. U.S. Agent Name and Address: 280 Utah Avenue South San Francisco, California 94080 Contact Person Steven M. Kay (714) 730-5000 Manufacturing Site Toshiba America MRI, Inc. 4. 280 Utah Avenue South San Francisco, California 94080 DATE OF SUBMISSION: November 15, 1996

DEVICE DESCRIPTION 6.

7. SAFETY PARAMETERS

	MRT-35A	MRT-35A	Flexart™
	9.0 Upgrade	8.0 Upgrade
Maximum static field strength:	0.35 T	same	0.5 T
Rate of change of magnetic field:	6.83 T/sec	same	11 T/sec
Max. radio frequency power deposition:	0.3 W/kg	0.34 W/kg	<0.256 W/kg
Acoustic Noise levels:	110.4 db(max)	101.6 db(max)	100.2 db(max)

{1}------------------------------------------------

510(k) Summary (cont'd)

8. IMAGE PERFORMANCE PARAMETERS

	MRT-35A9.0 Upgrade	MRT-35A8.0 Upgrade	FlexartTM
Specification Volume: Head:	10cm dsv	10cm dsv	10.4cm dsv
Body:	20cm dsv	20cm dsv	10.4cm dsv

Sample phantom images and clinical images were presented for all new sequences, demonstrating conformance with consensus standards requirements for Signal-to-Noise ratio, Uniformity, Slice Profiles, Geometric Distortion and Slice Thickness/Interslice Spacing.

9. INTENDED USE

1. Anatomical region:	Head, Body, Spine, Neck, TMJ, and Heart
2. Nuclei excited:	Hydrogen
3. Diagnostic Uses:	Imaging of the whole body (including the head,abdomen, heart, pelvis, spine, blood vessels, limbs andextremities), fluid visualization, 2D/3D Imaging, MRAngiography, MR Fluoroscopy.

10. EQUIVALENCY INFORMATION

Toshiba America MRI, Inc. (TAMI) believes the MRT-35A v9.0 is substantially equivalent to the MRT-35A with Version 8.0 series upgrade and Flexart™ diagnostic magnetic resonance systems because it consists of hardware and software modifications that do not introduce new questions of safety or efficacy, nor does it introduce new indications for use. The MRT-35A Version 8 upgrade was cleared by K945798 and its latest software Version 8.5CD is described in K961842. The Flexart™ was cleared by K933018 and its latest software V3.1 is described in K962138. Operationally, the MRT-35A version 9.0 upgrade is based on the software technology of the Flexart™. The MRT-35A Version 9.0 Upgrade makes no change however, to the superconducting magnet, gradient coil, gradient power, MRT-35 coil set or patient couch from the prior MRT-35A upgrade: Version 8. The computer system, applications software, sequences and user console electronics compose is changed in the MRT-35 9.0 Upgrade and these components are based on those found in FlexartM. Manufacturing Practices requirements and software development procedures are unchanged from those already in effect for the FlexartTM

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.