Slice-selective fat saturation in MR angiography using spatial-spectral selective prepulses

✍ Scribed by Jürgen Forster; Fritz Schick; Johannes Breuer; Ludger Sieverding; Otto Lutz

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 843 KB
• Volume: 8
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.1880080311

✦ Synopsis

Abstract

Presaturation of fat signals by frequency‐selective radiofrequency (RF) pulses is often applied in MR angiography to improve the visualization of the blood vessels. Unfortunately, standard fat saturation methods might cause a considerable reduction of the blood signal in the measured slices. This effect is caused by an attenuation of blood magnetization in remote tissue regions with water protons showing a similar Larmor frequency as the fat protons in the recorded slice. The affected blood water protons subsequently flow into the recorded slice and provide low signal intensity. Suitable spatial‐spectral selective methods for slice‐selective fat saturation were developed to avoid this unwanted effect. A spatial‐spectral fat saturation technique was compared with a corresponding only spectrally selective approach. Both saturation techniques were included in a standard two‐dimensional (2D) cine sequence and applied in angiographic examinations of the thighs. The results indicate that spatial‐spectral saturation (acting slice selectively) leads to a clearly higher blood signal intensity in fat‐suppressed MR angiography compared with standard techniques, especially in measurements performed during the systolic phase of the cardiac cycle.