Athey T W
Center for Devices and Radiological Health, Food and Drug Administration, Rockville, Maryland 20857.
Magn Reson Med. 1989 Feb;9(2):177-84. doi: 10.1002/mrm.1910090204.
A simple model of power deposition in the head is presented in which the temperature increase in the head in general and, in particular, in a small spherical region of unperfused tissue contained within the head is calculated. The result of the calculation provides a limit on the SAR needed to ensure that a 1 degree C temperature rise is not exceeded for unperfused spheres of different sizes, imaging sessions of different lengths of time, and different blood flow rates to the head. The model assumes that the rest of the body during a head imaging session can act as a perfect heat sink at 37 degrees C. The model suggests that current practices in MRI imaging will not cause a temperature rise in the center of small unperfused regions such as the eye of more than 1 degree C.
本文提出了一种头部功率沉积的简单模型，该模型用于计算头部整体的温度升高，特别是头部内包含的未灌注组织的小球形区域的温度升高。计算结果给出了在不同大小的未灌注球体、不同时长的成像会话以及不同头部血流速率的情况下，确保未灌注球体温度升高不超过1摄氏度所需的比吸收率（SAR）的限制。该模型假设在头部成像会话期间身体的其余部分可作为37摄氏度的理想散热体。该模型表明，当前MRI成像的操作不会导致小的未灌注区域（如眼睛）中心的温度升高超过1摄氏度。
