TRADITIONAL POSTER - ismrm

Poster Sessions
1719. Improved Venous Output Function Using MR Signal Phase for Quantitative 2D DCE-MRI in Human
Brain
Claire Foottit 1 , Greg O. Cron 2 , Thanh Binh Nguyen 2,3 , Matthew J. Hogan 2,3 , Ian Cameron, 12
1 Carleton University, Ottawa, Ontario, Canada; 2 Diagnostic Imaging, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada;
3 University of Ottawa, Ottawa, Ontario, Canada
For quantitative DCE-MRI of the human brain, the Gd concentration-vs-time in the superior sagittal sinus gives the venous output function (VOF). The
VOF can be used to correct errors in the arterial input function, which is crucial for accurate estimation of perfusion parameters. For measuring the VOF,
MR signal phase has several advantages over MR signal magnitude: superior SNR; linearity with Gd concentration; and insensitivity to blood flow, partial
volumes, and flip angle variations. This work showed that phased-derived VOFs have improved accuracy and precision compared with magnitude-derived
VOFs for multislice (2D) DCE-MRI studies of the human brain (n=28).
1720. Accuracy of T1-Fitting for Pharmacokinetic Analysis of Dynamic Contrast-Enhanced MRI
Paul Wessel de Bruin 1 , Maarten J. Versluis 1 , Erlangga Yusuf 2 , Monique Reijnierse 1 , Iain Watt 1 , Matthias J
P van Osch 1
1 Radiology Department, Leiden University Medical Center, Leiden, Netherlands; 2 Rheumatology Department, Leiden University
Medical Center, Leiden, Netherlands
The accuracy of Arterial Input Function and tissue response curve calculation in Dynamic Contrast-Enhanced MRI and Pharmacokinetic Analysis can be
improved by calculating T1-maps after contrast administration and dynamic acquisition. The resulting T1-fits have lower standard deviation and a higher
signal-to-noise ratio which translates linearly to improved concentration curve estimation.
1721. Partial Volume Correction of Arterial Input Functions in T1-Weighted Dynamic Contrast-Enhanced
MRI
Paul Wessel de Bruin 1 , Monique Reijnierse 1 , Matthias Jozef Petrus van Osch 1
1 Radiology Department, Leiden University Medical Center, Leiden, Netherlands
A partial volume correction method for Dynamic Contrast-Enhanced MRI is presented that can correct for underestimation of first bolus passage in T1-
weighted MRI. The method improves the robustness and precision of AIF measurement, even in very small ROIs, provided that the artery is oriented parallel
to the main magnetic field.
1722. Improved T1 Mapping with Iterative Actual Flip-Angle Imaging (IAFI) Technique
Yiqun Xue 1 , Mark A. Rosen 1 , Hee Kwon Song 1
1 Radiology, University of Pennsylvania, Philadelphia, PA, United States
Actual flip angle imaging (AFI) technique was recently developed to estimate the true flip angle and has been used in conjunction with the variable flip
angle (VFA) technique for improved T1 measurement accuracy. One of the limitations of AFI, however, is that the method assumes that T1 is much greater
than the repetition time TR. When this assumption is violated, large errors can result in both the flip angle and T1 estimation. We propose an novel iterative
AFI method which yields accurate T1 values without requiring that TR