Quality assurance and system stability of a clinical MRI-guided focused ultrasound system: Four-year experience
Quality assurance and system stability of a clinical MRI-guided focused ultrasound system: Four-year experience
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DOI：
10.1118/1.2352853
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发表时间：
2006-11-01
期刊：
影响因子：
3.8
通讯作者：
Hynynen, Kullervo
中科院分区：
文献类型：
--
作者：
McDannold, Nathan;Hynynen, Kullervo
回顾性评价MRI引导聚焦超声系统质量保证方法的4年经验，该系统使用超声/MRI体模加热期间采集的温度图。该质量保证方法在148例临床子宫肌瘤热消融治疗前进行。对峰值温升的稳定性、靶向精度、加热区的形状和成像中的噪声水平进行了评价。气温上升的峰值在前三年基本稳定。第三年后更换系统时，观察到加热量增加。在随后的临床治疗中考虑了这种增加的检测。温度图检测到一个小的二级热点，并在系统校准后得到解决。温度图中体模未加热区域的平均标准差为0.5 +/- 0.2 ℃;除一个程序外，所有程序的平均标准差均小于1 ℃。两个径向方向的平均初始定位误差为2.8 +/- 1.8和2.8 +/- 2.1 mm，沿超声束方向的平均初始定位误差为7.7 +/- 2.9 mm沿着。加热曲线的宽度在四年内是一致的。这种评估性能的简单方法似乎对系统性能的微小变化很敏感，而系统性能在四年的时间内足够稳定。(c)2006年美国医学物理学家协会。
To retrospectively evaluate the four-year experience of a quality assurance method for a MRI-guided focused ultrasound system that uses temperature maps acquired during heating in an ultrasound/MRI phantom. This quality assurance method was performed before 148 clinical uterine fibroid thermal ablation treatments. The stability of the peak temperature rise, the targeting accuracy, the shape of the heated zone, and the noise level in the imaging was evaluated. The peak temperature rise was mostly stable for the first three years. An increase in heating was observed when the system was replaced after year three. Detection of this increase was taken into account in the subsequent clinical treatments. A small secondary hotspot was detected by the temperature maps and was seen to be resolved after system calibration. The average standard deviation in unheated regions of the phantom in the temperature maps was 0.5 +/- 0.2 degrees C; it was less than 1 degrees C in all but one procedure. The average initial targeting error was 2.8 +/- 1.8 and 2.8 +/- 2.1 mm in two radial directions and 7.7 +/- 2.9 mm along the ultrasound beam direction. The width of the heating profile was consistent over the four years. This simple method to evaluate the performance appeared to be sensitive to small changes in system performance, which was adequately stable over a four-year time period. (c) 2006 American Association of Physicists in Medicine.