Bruce Shawn Spottiswoode1,2, Michael Markl3
1MRC/UCT Medical Imaging
Research Unit, Department of Human Biology, University of Cape Town, Cape
Town, Western Cape, South Africa; 2Radiology, University of
Stellenbosch, Cape Town, Western Cape, South Africa; 3Department
of Radiology, Medical Physics, University Medical Center, Freiburg
University, Freiburg, Germany
Flow sensitive MRI techniques are typically based on gradient echo (GE) imaging. GE offers a relatively low SNR for imaging cerebrospinal fluid (CSF) because of its long T1 relaxation time. We have developed a spin echo (SE) phase contrast (PC) velocity encoding sequence, and compared this to a standard GE-PC sequence using both phantom and in vivo experiments. SE-PC is only suitable for measuring slow flow because of the relatively long TEs and the need for refocusing pulse crusher gradients. A 2-3 fold increase in SNR has been demonstrated for CSF when comparing the technique to conventional multi-phase GE-PC imaging. Reduced distortions at air-tissue interfaces and improved velocity background contrast in the flow images can also be appreciated.