Method for operating a nuclear magnetic resonance tomography apparatus

US4825159A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Arnulf Oppelt · Spardorf, DE
• Hubertus Fischer · Bamberg, DE
• Helmut Barfuss · Erlangen, DE

Key dates

• Filing date: Apr 19, 1988
• Grant date: Apr 25, 1989
• Expiry date: Apr 19, 2008

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/50
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An examination subject is irradiated with a sequence of RF pulses. Negative gradient pulses G.sub.z3 and G.sub.y4, as well as a phase-coding gradient G.sub.x2 are generated preceding each RF pulse. Negative gradient pulses G.sub.z2 and G.sub.y1, as well as a phase-coding gradient G.sub.x1, are generated following each RF pulse. The phase-coding gradient G.sub.x1 is inverted relative to the phase-coding gradient G.sub.x2. The negative gradient pulse G.sub.y1 is followed by a positive gradient pulse G.sub.y2 which serves as a read-out gradient during which a first signal S.sub.1 is received. A positive gradient pulse G.sub.y3 is generated preceding the negative gradient pulse G.sub.y4, the positive gradient pulse G.sub.y3 serving as a read-out gradient during which a second signal S.sub.2 is received. Two signals having different T.sub.2 weighting are thus obtained in each measuring sequence, without extending the measuring time. Two images having different T.sub.2 contrast, and thus increased diagnostic value, can thus be produced.