Date of Award

Summer 8-15-2015

Author's Department

Biomedical Engineering

Degree Name

Doctor of Philosophy (PhD)

Degree Type



This thesis focused on applications of magnetic resonance imaging (MRI) in radiotherapy. Two important aspects of these applications, imaging of organ motion and the MRI based treatment planning, were studied in detail in this thesis.

To study the MRI application in motion imaging, novel four dimensional MRI (4DMRI) techniques were developed. The main purpose of this study is to acquire high quality 4D images within clinically acceptable scan time. Both simulation and healthy volunteer studies were conducted for different 4DMRI techniques. The results were analyzed and compared. Some advanced techniques, such as amplitude and phase based triggering 4DMRI, were investigated to accelerate the image acquisition speed.

For MRI based treatment planning, the concept of “intrinsic dosimetric error” of bulk density overridden plans was created and evaluated using patients’ data. This study demonstrates that the magnitude of the intrinsic dosimetric error depends on tumor sites, tissue segmentation methods and the inhomogeneity of tissue electron densities. The conclusion is meaningful for the future MRI based treatment planning research.


English (en)


Lihong Wang

Committee Members

Yanle Hu, Lihong Wang, Mark Anastasio, Shelton Caruthers, Hui Li, Sasa Mutic


Permanent URL:

Available for download on Thursday, August 15, 2115

Included in

Engineering Commons