Calculation methods for ventricular diffusion-weighted imaging thermometry: phantom and volunteer studies
Calculation methods for ventricular diffusion-weighted imaging thermometry: phantom and volunteer studies
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DOI：
10.1002/nbm.1755
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发表时间：
2012-02-01
影响因子：
2.9
通讯作者：
Sugimoto, Naozo
中科院分区：
文献类型：
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作者：
Sakai, Koji;Yamada, Kei;Sugimoto, Naozo
最近提出了一种利用扩散加权成像（DWI）测量侧脑室温度的方法。该方法使用预定的任意阈值，但是更客观的计算方法将是有用的。因此，我们比较了四种不同的计算方法，其中两种是新创建的，不需要预先确定的阈值。用热水（35.0-38.8 ℃）填充矩形聚对苯二甲酸乙二醇酯瓶（8 x 10 x 28 cm（3）），并用作水模。本研究使用了23名健康受试者（年龄26- 75岁;平均值±标准差，50.13 ± 19.1岁）的DWI数据。使用以下等式计算温度：T（摄氏度）=2256.74/ln（4.39221/D）+/-273.15，其中D是扩散系数。采用四种方法计算平均心室温度：两种阈值法和两种直方图曲线拟合法。作为参考，我们使用在鼓膜处测量的温度，该温度已知比大脑温度低约1摄氏度。水银测温法和经典的水模预定阈值方法之间的平均温差分别为0.10 +/- 0.42和0.05 +/- 0.41 ℃。然而，直方图曲线拟合法得出的温度略低于水银测温法（平均差值分别为-0.24 +/- 0.32和-0.14 +/- 0.31摄氏度）。鼓膜温度测定法和经典的预定阈值方法之间的温度差异非常小（分别为+0.01和-0.07摄氏度）。然而，在人类中，直方图曲线拟合方法产生的温度大约高出1摄氏度（分别为+1.04摄氏度和+1.36摄氏度），这表明以这种方式测量的温度更接近真实的大脑温度。直方图曲线拟合方法更客观，更好地匹配估计的脑温度比经典的预定阈值的方法，虽然在前一种方法的标准偏差较宽。版权所有（C）2011约翰威利父子有限公司
A method for the measurement of temperature in the lateral ventricle using diffusion-weighted imaging (DWI) has been proposed recently. This method uses predetermined arbitrary thresholds, but a more objective method of calculation would be useful. We therefore compared four different calculation methods, two of which were newly created and did not require predetermined thresholds. A rectangular polyethylene terephthalate bottle (8 x 10 x 28 cm(3)) was filled with heated water (35.0-38.8 degrees C) and used as a water phantom. The DWI data of 23 healthy subjects (aged 26-75years; mean +/- standard deviation, 50.13 +/- 19.1years) were used for this study. The temperature was calculated using the following equation: T(degrees C)=2256.74/ln(4.39221/D) +/- 273.15, where D is the diffusion coefficient. The mean ventricular temperature was calculated by four methods: two thresholding methods and two histogram curve-fitting methods. As a reference, we used the temperature measured at the tympanic membrane, which is known to be approximately 1 degrees C lower than the brain temperature. The averaged differences in temperature between mercury thermometry and classical predetermined thresholding methods for the water phantom were 0.10 +/- 0.42 and 0.05 +/- 0.41 degrees C, respectively. The histogram curve-fitting methods, however, yielded temperatures a little lower (averaged differences of -0.24 +/- 0.32 and -0.14 +/- 0.31 degrees C, respectively) than mercury thermometry. There was very little difference in temperature between tympanic thermometry and classical predetermined thresholding methods (+0.01 and -0.07 degrees C, respectively). In humans, however, the histogram curve-fitting methods yielded temperatures approximately 1 degrees C higher (+1.04 degrees C and +1.36 degrees C, respectively), suggesting that temperatures measured in this way more closely approximate the true brain temperature. The histogram curve-fitting methods were more objective and better matched the estimated brain temperature than did classical predetermined thresholding methods, although the standard deviation was wider in the former methods. Copyright (C) 2011 John Wiley & Sons, Ltd.