Using Magnetic Resonance Imaging to Simultaneously onitor Temperature and Magnetization Transfer for High-Intensity Focused Ultrasound Treatment
Date Issued
2009
Date
2009
Author(s)
Peng, Hsu-Hsia
Abstract
Abstracthe utilization of MRI for guiding high-intensity focused ultrasound (HIFU) beams not only increases the localization accuracy during HIFU procedures but also allows evaluation of HIFU-induced lesions after treatment. Our study investigated the feasibility of estimating temperature changes and magnetization transfer (MT) contrast simultaneously during HIFU heating procedures, using a dual gradient-echo technique interleaved with ON and OFF off-resonant MT pulses. Egg white phantom studies and ex vivo experiments on the porcine liver and muscle tissues demonstrated that this method exhibited high consistence with thermal dose in respect of determining lesion size. Even though physical heat elevation disperses quickly after heating procedure, the biological change in MT ratio (MTR) due to tissue damage does not diminish. Moreover, thermal dose map derived from physical temperature elevation could sharply define the lesion size, whereas MTR map showed a distribution of biological effect of cell damage. The distribution of MTR, which was invisible in thermal dose map, might be helpful for efficiently arranging the locations and sonication conditions of subsequent heating spots, particularly in a spot-by-spot treatment planning. In conclusion, the proposed method could potentially improve HIFU heating efficiency and reduce unwanted heating damage to tissues nearby the targeting area.ey words: temperature, magnetization transfer, thermal therapy, high-intensity focused ultrasound, MR guided, tissue damage.
Subjects
temperature
magnetization transfer
thermal therapy
high-intensity focused ultrasound
MR guided
tissue damage
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-98-D93921028-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):e3c988e90a4b1fb18f16f31d7491d128