Peng HH, Huang TY, Tseng WYI, Lin EL, Chung HW, Wu CC, Wang YS, Chen WS. Simultaneous temperature and magnetization transfer (MT) monitoring during high-intensity focused ultrasound (HIFU) treatment: preliminary investigation on ex vivo porcine muscle.
J Magn Reson Imaging 2009;
30:596-605. [PMID:
19630078 DOI:
10.1002/jmri.21860]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
PURPOSE
To measure temperature change and magnetization transfer ratio (MTR) simultaneously during high-intensity focused ultrasound (HIFU) treatment.
MATERIALS AND METHODS
This study proposed an interleaved dual gradient-echo technique to monitor the heat and tissue damage brought to the heated tissue. The technique was applied to tissue samples to test its efficacy.
RESULTS
Ex vivo experiments on the porcine muscle demonstrated that both temperature changes and MTR exhibited high consistency in localizing the heated regions. As the heat dissipated after the treatment, the temperature of the heated regions decreased rapidly but MTR continued to be elevated. Moreover, thermal dose (TD) maps derived from the temperature curves demonstrated a sharp margin in the heated regions, but MTR maps may show a spatial gradient of tissue damage, suggesting complimentary information provided by these two measures.
CONCLUSION
In a protocol of spot-by-spot heating over a large volume of tissue, MTR provides additional values to mark the locations of previously heated regions. By continuously recording the locations of heated spots, MTR maps could help plan the next target spots appropriately, potentially improving the efficiency of HIFU treatment and reducing undesirable damage to the normal tissue.
Collapse