Conventional perfusion magnetic resonance imaging with dynamic susceptibility using a contrast agents has been playing a dominant role on diagnosing a variety of cerebral nervous system disease due to lack of radiation and widespread availability. However, reliable quantification of cerebral perfusion has been elusive and challenging. The bookend method is presented for quantifying cerebral perfusion in this study. The bookend method consists of inversion recovery Lock-Locker echo planar imaging (IR LL-EPI) and conventional perfusion weighted imaging (PWI) sequence with a contrast injection. The fast T1 measurements are performed before and after PWI. From those T1 measurements, absolute T1-derived cerebral blood volume (CBV) or CBV in a steady state from pre- and post-contrast injection (CBVSS) values are measured. Relative perfusion images acquired from PWI scanning are calibrated based on absolute CBVSS value. In this study, IR LL-EPI sequence for the fast T1 measurement is developed and the accuracy of the T1 measurement is validated in phantom and human study. To improve accuracy of CBVSS measurement, water exchange effects are considered and water exchange rates are measured. Finally CBVSS measurement with water exchange effects correction is presented. Combined with this method, the bookend method with water exchange effects correction is presented for quantifying cerebral perfusion. To remove an user dependency in quantification, a fully automatic image post-processing algorithm is proposed and tested in reproducibility study. Reproducibility is validated with scan and re-scan of both controls (n=8) and patients (n=25). From large number of sample (n=175), age and gender dependency of cerebral perfusion is presented with bookend method with water exchange effects correction using automatic algorithm. Finally, this method is implemented in a clinical use to determine ischemic threshold for a cell death in stroke patients. Ischemic threshold values are determined and compared using both quantitative cerebral blood flow and Tmax in white matter and gray matter separately.

Last modified

• 08/27/2018

Creator

• Wanyong Shin

DOI

• https://doi.org/10.21985/N2HT5B

Subject

• Biomedical Engineering

Keyword

• MR imaging
• Quantitative Cerebral Perfusion
• Cerebral blood volume
• Cerebral blood flow

Date created

• 2007-08-29

Resource type

• Dissertation

Rights statement

• In Copyright