Yankelevitz D F, Henschke C I, Davis S D
Department of Radiology, New York Hospital-Cornell Medical Center, NY 10021.
J Thorac Imaging. 1994 Spring;9(2):108-11. doi: 10.1097/00005382-199421000-00011.
The purpose of this study was to investigate the factors that help determine the needle tip location during computed tomographic (CT)-guided thin needle aspirations. We devised a model using a bottle filled with air, mineral oil, and water into which we could insert a needle. We then obtained CT images using both 5- and 10-mm slice thicknesses and determined the Hounsfield units (HUs) in regions of interest surrounding the needle shaft and some distance away from the needle shaft. We demonstrated that the presence of the needle increases the average HUs of the background both in the same region of interest and in the region of interest some distance from the needle. This effect is seen in air, fat, and water and thus occurs regardless of the attenuation of the background medium. A decrease in slice thickness causes this effect to be even more marked. These experimental results coincided with the theoretical results obtained from an equation that approximates the HUs of the pixels.
本研究的目的是调查在计算机断层扫描（CT）引导下进行细针穿刺抽吸时，有助于确定针尖位置的因素。我们设计了一个模型，使用一个装有空气、矿物油和水的瓶子，我们可以将针插入其中。然后，我们使用5毫米和10毫米的层厚获取CT图像，并确定针杆周围感兴趣区域以及距针杆一定距离处的感兴趣区域的亨氏单位（HU）。我们证明，针的存在会增加同一感兴趣区域以及距针一定距离处的感兴趣区域的背景平均HU。在空气、脂肪和水中都能看到这种效应，因此无论背景介质的衰减如何都会发生。层厚的减小会使这种效应更加明显。这些实验结果与从近似像素HU的方程得到的理论结果一致。
