Quantification of cerebral perfusion and cerebrovascular reserve using Turbo‐QUASAR arterial spin labeling MRI

Purpose
The design and performance of a novel head coil setup for urn:x-wiley:07403194:media:mrm27953:mrm27953-math-0009P spectroscopy at ultra‐high field strengths (7T) is presented. The described system supports measurements at both the urn:x-wiley:07403194:media:mrm27953:mrm27953-math-0010H and urn:x-wiley:07403194:media:mrm27953:mrm27953-math-0011P resonance frequencies.

Methods
The novel coil consists of 2, actively detunable, coaxial birdcage coils to give homogeneous transmit, combined with a double resonant 30 channel receive array. This allows for anatomical imaging combined with urn:x-wiley:07403194:media:mrm27953:mrm27953-math-0012P acquisitions over the whole head, without changing coils or disturbing the subject. A phosphate buffer phantom and 3 healthy volunteers were scanned with a pulse acquire CSI sequence using both the novel array coil and a conventional transceiver birdcage. Four different methods of combining the array channels were compared at 3 different levels of SNR.

Results
The novel coil setup delivers significantly increased urn:x-wiley:07403194:media:mrm27953:mrm27953-math-0013P SNR in the peripheral regions of the brain, reaching up to factor 8, while maintaining comparable performance relative to the birdcage in the center.

Conclusions
The new system offers the potential to acquire whole brain urn:x-wiley:07403194:media:mrm27953:mrm27953-math-0014P MRSI with superior signal relative to the standard options.