Medical Physics Seminar – Monday, October 8, 2012
Non-contrast-enhanced intracranial MR angiography with Pseudo Continuous Arterial Spin Labeling (PCASL) and Accelerated 3D Radial Acquisition (VIPR)
Huimin Wu (student of Dr. Walter Block)
Research Assistant, Department of Medical Physics, UW-School of Medicine & Public Health, Madison, WI - USA -
X-ray Digital subtraction angiography (DSA) has long been considered the reference standard for intracranial angiography, however is invasive and delivers ionizing radiation. In this work, a non-contrast-enhanced MR angiography technique has been developed as a potential alternative. It combines pseudo continuous arterial spin labeling (PCASL) technique and 3D accelerated radial acquisition (VIPR). This technique has proved many potential, such as: 3D angio-architecture, flow filling dynamics, selective vessel labeling. Two studies were presented: the first study focusing on static PCASL-VIPR technique was conducted on healthy subjects (N=5) and diseased subjects (N=5). By comparison with 3D TOF, static PCASL-VIPR shows advantages on head coverage, isotropic resolution, near-zero background, and especially sensitivity to slow flow; the second study focusing on dynamic PCASL-VIPR technique was conducted on both digital phantoms and patients with previously diagnosed AVMs/DAVFs. The results demonstrated that dynamic PCASL-VIPR is able to provide qualitative and quantitative hemodynamics that will help diagnosis of AVM patients with little sacrifice of image quality. Preliminary study of PCASL-VIPR applied on vessel-selective labeling and further acceleration with compressed sensing was also conducted and results will be discussed.