MR Digital Subtraction Angiography

Analysis of Subtraction Methods in 3D Contrast-Enhanced MR Digital Subtraction Angiography Yuexi Huang Master of Science 2001 Department of Medical Biophysics University of Toronto 3D Contrast-enhanced MR angiography is promising as a replacement to catheter-based x-ray angiography due to its non-invasive nature. However, the image quality of MR angiography is still inferior to that of x-ray angiography at present, particularly in terms of image resolution and arterial conspicuity. Image subtraction is one of the techniques to improve arterial conspicuity in first-pass MR angiography. Three subtraction methods can be chosen in practice: cornplex subtraction, magnitude subtraction and MIP subtraction. This thesis compares and analyses the effectiveness of these three algorithms under different situations through cornputer simulations, phantom studies, and clinical studies. The principles for choosing the appropriate algorithm are provided. Future techniques to improve the image quality in MR angiography are also discussed.