Ultrafast 1D MR thermometry using phase or frequency mapping
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Chang-Sheng Mei · Robert V. Mulkern · Koichi Oshio · Nan-kuei Chen · Bruno Madore · Lawrence P. Panych · Kullervo Hynynen · Nathan J. McDannold
- چاپ و سال / کشور: 2011
Description
Object To develop an ultrafast MRI-based temperaturemonitoring method for application during rapid ultrasound exposures in moving organs. Materials and methods A slice selective 90. . 180. pair of RF pulses was used to solicit an echo from a column, which was then sampled with a train of gradient echoes. In a gel phantom, phase changes of each echo were compared to standard gradient-echo thermometry, and temperature monitoring was tested during focused ultrasound sonications. Signal- to-noise ratio (SNR) performance was evaluated in vivo in a rabbit brain, and feasibility was tested in a human heart. Results The correlation between each echo in the acquisition and MRI-based temperature measurements was good (R = 0.98 پ} 0.03). A temperature sampling rate of 19Hz was achieved at 3T in the gel phantom. It was possible to acquire the water frequency in the beating heart muscle with 5-Hz sampling rate during a breath hold. Conclusion Ultrafast thermometry via phase or frequency monitoring along single columns was demonstrated. With a temporal resolution around 50 ms, it may be possible to monitor focal heating produced by short ultrasound pulses.
Magn Reson Mater Phy DOI 10.1007/s10334-011-0272-9 Received: 21 November 2010 / Revised: 28 June 2011 / Accepted: 30 June 2011
