Functional MRI using multiple receiver coils: BOLD signal changes and signal-to-noise ratio for three-dimensional-PRESTO vs. single shot EPI in comparison to a standard quadrature head coil.
OBJECTIVE
To compare the performance of single shot echo planar imaging (SSEPI) with three-dimensional-multishot echo-planar imaging (EPI) based on principles-of-echo-shifting-with-a-train-of-observations (PRESTO) in combination with a standard quadrature head coil and, as an alternative, a multiple receiver coil in intraoperative functional magnetic resonance imaging (fMRI).


METHODS
Six healthy subjects underwent fMRI with visual stimulation using a SSEPI and a PRESTO-sequence with both coil systems. Statistical evaluation was done with a scanner-based post-processing software and SPM 99. The number of activated voxels in the visual cortex, the percent signal change between rest and activation, and finally the signal-to-noise ratio (SNR) during time course were measured and compared for both coil systems and both sequences, used in four different combinations.


RESULTS
Blood oxygen level dependent (BOLD) signal changes were the lowest with PRESTO and standard head coil and the highest for SSEPI and phased array coil. For the latter combination, a significantly higher signal change and larger activation size was observed together with a better SNR. SSEPI yielded similar performance using both coils.


CONCLUSIONS
SSEPI was superior due to its better SNR and a higher BOLD signal change in the defined settings, irrespective of the coil used. In a stereotactical setup the phased array coil can be used to generate fMRI data without loss of image quality.
Department of Radiology, University of Cologne, Joseph Stelzmann-Strasse 9, 50924 Köln, Germany. Volker.Hesselmann@uni-koeln.de
Volker
V
Hesselmann
Ralf
R
Girnus
Christoph
C
Wedekind
Stefan
S
Hunsche
Juergen
J
Bunke
Oliver
O
Schulte
Bettina
B
Sorger
Kathrin
K
Lasek
Barbara
B
Krug
Volker
V
Sturm
Klaus
K
Lackner
D000328:Adult; D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008297:Male; D010100:Oxygen / Q000097:blood*; D012815:Signal Processing, Computer-Assisted
D010100:Oxygen