Davidson Lance E, Kuk Jennifer L, Church Timothy S, Ross Robert
School of Physical and Health Education, Division of Endocrinology and Metabolism, Department of Medicine, Queen's Univ., Kingston, Ontario, Canada K7L 3N6.
J Appl Physiol (1985). 2006 Mar;100(3):864-8. doi: 10.1152/japplphysiol.00986.2005. Epub 2005 Nov 17.
To develop a protocol for measurement of liver fat using computed tomography (CT), we conducted a preliminary study with 118 men and 76 women to determine a readily identifiable vertebral landmark at which the CT image displayed both liver and spleen. Analysis of five landmarks revealed that the CT image obtained at the T12-L1 level simultaneously displayed the liver and spleen in 90% of the men and women. The T12-L1 protocol was cross-validated on a sample of 130 men and 113 women. In this sample, we also assessed the regional characteristics of liver and spleen tissue attenuation at the T12-L1 level by subdividing each image into quartiles from anterior to posterior, each of which were further divided into medial and lateral regions. A similar analysis was performed on images located 12 mm above and below T12-L1. The T12-L1 image displayed both liver and spleen in 92% (403 of 437) of the combined study sample. There was a significant (P<0.005) stepwise increase in attenuation values [Hounsfield units (HU)] from the inferior to superior image. Although some significant (P<0.05) differences were observed between the eight regions by comparison to the whole liver or spleen, the average magnitude of the difference was <2.0 HU for liver and <3.5 HU for spleen. Acquisition of a single CT image at the T12-L1 level is a practical and reliable method for routine measurement of liver fat in research and clinical settings.
为制定一种使用计算机断层扫描（CT）测量肝脏脂肪的方案，我们对118名男性和76名女性进行了一项初步研究，以确定一个易于识别的椎体标志，在该标志处CT图像可同时显示肝脏和脾脏。对五个标志的分析显示，在T12-L1水平获得的CT图像在90%的男性和女性中同时显示肝脏和脾脏。T12-L1方案在130名男性和113名女性的样本上进行了交叉验证。在该样本中，我们还通过将每个图像从前到后细分为四分位数，再将每个四分位数进一步分为内侧和外侧区域，评估了T12-L1水平肝脏和脾脏组织衰减的区域特征。对T12-L1上方和下方12 mm处的图像进行了类似分析。在合并研究样本的92%（437例中的403例）中，T12-L1图像同时显示肝脏和脾脏。从下到上的图像中，衰减值[亨氏单位（HU）]有显著（P<0.005）的逐步增加。尽管与整个肝脏或脾脏相比，在八个区域之间观察到了一些显著（P<0.05）差异，但肝脏的平均差异幅度<2.0 HU，脾脏的平均差异幅度<3.5 HU。在T12-L1水平采集单幅CT图像是在研究和临床环境中常规测量肝脏脂肪的一种实用且可靠的方法。
