Pulse sequence for a nuclear magnetic resonance apparatus

US5432448A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Oliver Heid · Erlangen, DE
• Michael Deimling · Baiersdorf, DE

Key dates

• Filing date: Sep 20, 1994
• Grant date: Jul 11, 1995
• Expiry date: Sep 20, 2014

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/5617
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sequence of chronologically non-equidistant radio frequency excitation pulses and a first gradient are activated during an excitation phase. The existing spin magnetization is divided into sub-groups by each excitation pulse that follows the first excitation pulse. A chronologically graduated focusing of the individual sub-groups ensues during the read-out phase under a further gradient. A number of nuclear magnetic resonance signals can thereby be acquired following a single excitation phase, so that a short image pick-up time becomes possible, without the necessity of a fast switching of the gradients. Further, pure spin echoes can be acquired, which are insensitive to local field inhomogeneities in comparison to gradient echoes.