Matus Straka1, Rexford D. Newbould2,
1Radiology, Stanford University,
Stanford, CA, United States; 2Clinical Imaging Centre,
GlaxoSmithKline, London, United Kingdom; 3Commision for Scientific
Visualization, Austrian Academy Of Sciences, Vienna, Austria; 4Stroke
Center, Stanford University Medical Center, Stanford, CA, United States
Quantitative
perfusion measurements require accurate measurements of tracer concentration.
Magnitude T2*-based data suffer from various artifacts and non-linearities
and make quantification of (mainly vascular) tracer concentration difficult.
Concentration can be derived from change in resonante frequency (phase of MR
signal), however this effect depends on orientation of given vessel versus
main magnetic field. Image-based filtering to enhance cylindrical structures
is used to estimate vessel orientation from DSC-MRI data. This information is
used to correct the phase information and improve quantification of Gd
concentration in large vessels.
Keywords