On-Going Research

• I. MR Quantitation
• II. Computer Assisted Gamma Knife Radiosurgery (GKR)

I. MR Quantitation

MR image quality, i.e., image resolution, signal-to-noise ratio, etc., is affected by many factors. These include the strength and homogeneity of main magnetic field, the strength and linearity of gradient fields, imaging parameters TE/TR, and pulse sequence used, etc. In addition, image quality is seriously degraded by artifacts originated from vairous causes such as complex flows and voluntary and/or involuntary motions. All of these undesired effects could significantly hamper clinical diagnosis especially when the source of these artifacts are unknown. Our interests are to analyze the causes of these image artifacts and to develop methods to correct/compensate them to make quantitative evaluations feasible. The topics include:

• MRI-based radiation dosimetry: MRI-Fricke-infused dosimetry
• Projection reconstruction-based MR imaging
• MR diffusion/perfusion imaging
• Normal and complex in vivo blood flow measurements
• Motion artifact correction by navigator echo technique and/or fast imaging
• MR Image distortion correction

II. Computer Assisted Gamma Knife Radiosurgery (GKR)

This research focuses on the design and development of an automated treatment planning system to resolve the major difficulty, namely heavy time and experience dependency, faced in current gamma knife radiosurgery treatment planning practice. The emphases are:

• The application of artificial intelligence methods in GKR treatment planning
• The development of a PC-based dose calculation system
• The development and implementation of dose-volume optimization algorithms
• The development of an automated GKR treatment planning system