Magnetic resonance using a phase-modulated pulse train with a constant small flip angle, causing a constant in power Walsh transform of the pulse train sequence of phases

US8952691B2 · kind B2 · utility

Assignees

• RWTH Aachen · DE
• UNIVERSITY COLLEGE DUBLIN, NATIONAL UNIVERSITY OF IRELAND, DUBLIN · IE

Inventors

• Bernhard Blumich · Simmerath, DE
• Marcus Greferath · Dublin, IE
• Eimear Byrne · Guernal, IE
• Qingxia Gong · Aachen, DE

Key dates

• Filing date: Oct 8, 2009
• Grant date: Feb 10, 2015
• Expiry date: Apr 9, 2032

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/60
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method for performing magnetic resonance measurements on a sample includes applying a first predetermined number of pulse trains for excitation, each pulse train having a constant amplitude and including a second predetermined number of pulses spaced by a predetermined time interval. The pulse trains are modulated by a bent function. After each pulse, data is sampled. Preferably a square number of pulses is generated being constant in power, and the Walsh transform of the sequence of their phases is constant in power, so that the power of the excitation in time and frequency domain is constant. The method can reduce power requirements and may permit undercutting specific absorption rate (SAR) limits due to the small excitation power necessary to create time signals with reasonable signal to noise ratio.