Negative resistance preamplifier for inductively coupled local MRI coils

US10393831B2 · kind B2 · utility

Assignee

• The United States of America, as represented by the Secretary, Department of Health and Human Services · US

Inventors

• Joseph Murphy-Boesch · Rockville, US
• Stephen Dodd · Rockville, US
• Chunqi Qian · Rockville, US
• Alan Koretsky · Bethesda, US

Key dates

• Filing date: May 7, 2015
• Grant date: Aug 27, 2019
• Expiry date: Aug 19, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/5616
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A novel MRI-compatible amplifier design uses positive feedback from a low-noise Field-Effect Transistor to amplify the signal current within a resonant NMR coil. The amplified signal current in this low-power circuit produces RF flux can be coupled out to receiving loops positioned externally without significant loss in sensitivity. In other aspects, the amplifier may be remotely powered by external resonant loops, a small non-magnetic battery, or optical power, such that the NMR coil can be positioned during highly invasive procedures such as for surgical resection of tumors in deep-lying tissues to develop high-resolution images.