ELECTRONIC POSTER - ismrm

Thursday 13:30-15:30 Computer 125
13:30 5099. Correction of the Kinetic Parameters of Human Tissue Considering RF-Field
Inhomogeneities
Robert Merwa 1 , Gernot Reishofer 2 , Thorsten Feiweier 3 , Karin Kapp 4 , Franz Ebner 2 ,
Rudolf Stollberger 5
1 Medical Engineering, FH OÖ - Upper Austria University of Applied Sciences, Linz, Austria; 2 Department of
Radiology, Medical University of Graz, Graz, Austria; 3 Healthcare, Siemens AG, Germany; 4 Department of
Radiation Therapy, Medical University of Graz, Graz, Austria; 5 Institute of Medical Engineering, Graz
University of Technology, Graz, Austria
Dynamic contrast-enhanced MRI was performed at 3 T in combination with a flip angle mapping sequence in order to correct the
kinetic parameters of human tissue. Due to the local magnitude of these inhomogenities the values for the AIF and tissue
concentrations are widespread which lead to an overestimation or underestimation of K trans and V e . The peak of the arterial input
function decreases of about 60 % and the absolute difference of K trans and V e obtained with the AIF in two comparable arteries can be
improved by a factor up to 33 if the dynamic data are corrected accordingly.
14:00 5100. Registration of Histology and MR Images Using Local Rigid Registration and
Differential Evolution
Zhengyi Yang 1 , Viktor Vegh 1 , Deming Wang 1 , David Charles Reutens 1,2
1 University of Queensland, Brisbane, Queensland, Australia; 2 Royal Brisbane and Women's Hospital, Brisbane,
Queensland, Australia
Registration of histological sections and the corresponding MR images is a critical step in MR constrained histology volume
reconstruction. Histological sections with dislocated segments are problematic. This issue is addressed by employing a local rigid
registration method. The dislocated segments are identified by morphological operations and connectivity analysis. These segments
are treated as rigid bodies having independent degree-of-freedom of motion. The registration was to find the transformation matrix for
each segment to maximize the similarity, which was normal mutual information, between the transformed histological section and
target MR image. The method of differential evolution was used to find optimal registrations.
14:30 5101. A Method for Planning Interventions in the Brain with Straight Access Paths
Nikhil Navkar 1 , Zhigang Deng 1 , Jason Stafford 2 , Jeffrey Weinberg 3 , Nikolaos V. Tsekos 1
1 Computer Science, University fo Houston, Houston, TX, United States; 2 Imaging Physics, MD Anderson,
United States; 3 Neurosurgery, MD Anderson, United States
The aim of the work is to designed visualization techniques for preoperative planning of neurosurgical interventional procedures using
straight tabular tool. The visualization techniques include calculation of access maps on the surface of patient head, which help the
neurosurgeon in selecting the optimum point for insertion. The preliminary results show that it is possible to plan the trajectory of the
interventional tool to hit a target in such a way that it minimizes the trauma to vital structures inside the brain.
15:00 5102. Input Function Detection in MR Brain Perfusion Using a Blood Circulatory Model
Based Algorithm
Azimeh Noorizadeh 1 , Hassan Bagher-Ebadian 2,3 , Reza Faghihi 1 , Jayant Narang 4 , Rajan
Jain 4 , James Russel Ewing 2,3
1 Department of Nuclear Engineering, Shiraz University, Shiraz, Fars, Iran; 2 Department of Neurology, Henry
Ford Hospital, Detroit, MI, United States; 3 Department of Physics, Oakland University, Rochester, MI, United
States; 4 Department of Radiology, Henry Ford Hospital, Detroit, MI, United States
MR Quantification of the hemodynamic maps such as Cerebral Blood Volume, Mean Transit Time, and Cerebral Blood Flow in
perfusion studies is highly susceptible to selection of the correct Arterial Input Function (AIF) and a correct AIF selection could
substantially reduce bias in hemodynamic parameters. This study uses a blood circulatory model to construct an automatic and modelbased
algorithm for AIF detection in MR perfusion studies. The algorithm is used to detect the AIF from MR perfusion of four
patients with 19 slices. This study introduces a new and reliable (performance: 84%) algorithm for AIF detection in MR perfusion
studies.
Novel Image Analysis Techniques
Hall B Monday 14:00-16:00 Computer 126
14:00 5103. DIR Imaging Using GRAPPA for Cortical Thickness Estimation
Narae Choi 1 , Yoonho Nam 1 , Dong-Hyun Kim 1,2
1 Electrical and Electronic Engineering, Yonsei University, Sinchon dong, Seoul, Korea, Republic of;
2 Radiology, Yonsei University, Sinchon dong, Seoul, Korea, Republic of
Most gray matter volumetric studies use T1-weighted imaging such as MP-RAGE because it provides good contrast between white
matter and cortex. However, due to susceptibility artifact coming from the air-tissue interface, a reliable and accurate measurement is
difficult in the regions near the air-bone interface for T1-wieghted schemes. One way to alleviate this problem is to perform gray
matter spin-echo imaging through DIR sequence. One drawback of the DIR sequence, however, is its long scan time. We applied one