Sensitivity-encoded single-shot spiral imaging for reduced susceptibility artifacts in BOLD fMRI

✍ Scribed by Markus Weiger; Klaas P. Pruessmann; Robert Österbauer; Peter Börnert; Peter Boesiger; Peter Jezzard

• Book ID: 102952184
• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 981 KB
• Volume: 48
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.10286

✦ Synopsis

Abstract

Sensitivity encoding (SENSE) with iterative image reconstruction was used to shorten the readout duration in single‐shot spiral imaging by a factor of 2. This enabled susceptibility‐related blurring and signal loss artifacts to be reduced and spatial resolution to be improved. As a beneficial side effect, the gradient duty cycle was also reduced. The spiral SENSE technique was applied to functional MRI (fMRI) with blood oxygen level‐dependent (BOLD) contrast and compared to a conventional spiral acquisition. Stimulation experiments were performed in seven volunteers using motor, visual, and taste paradigms. The signal‐to‐noise ratio (SNR) and signal‐to‐fluctuation‐noise ratio (SFNR) of the SENSE acquisitions were reduced by 20% and 13%, respectively, with respect to the longer readout. The overall activation detected was comparable to that of the conventional spiral acquisition, even though difficulties in reproducing the stimulation response hampered the evaluation. In some cases, the application of SENSE enabled recovery of activation in regions affected by signal loss due to field inhomogeneity. Magn Reson Med 48:860–866, 2002. © 2002 Wiley‐Liss, Inc.