Department of Radiology, University of Wisconsin-Madison, Madison, WI 53705, USA.
AJR Am J Roentgenol. 2012 Sep;199(3):677-82. doi: 10.2214/AJR.11.7999.
The purpose of this study is to determine a concentration of iodinated contrast media in saline and 5% dextrose in water (D5W) for organ hydrodissection, a technique used to physically separate and protect tissues adjacent to thermal ablations.
A total of 28 samples were prepared from 1:1000-1:1 iohexol or iothalamate meglumine contrast media in either normal saline or D5W. Samples alone or juxtaposed with a homogeneous liver-mimicking phantom were imaged by CT using 80-120 kVp and 10-300 mAs. Mean CT numbers and noise were measured from the fluid, background air, phantom adjacent to the fluid, and phantom distant from the fluid. Visibility was determined from the contrast-to-noise ratio between the fluid and phantom, whereas streaking artifact was quantified by relative noise in the phantom. Measures were individually fit using multiple linear regression to determine an optimal contrast-to-fluid ratio for increased visualization without streaking. Contrast media- and blood-doped saline and D5W were also tested to determine whether such doping altered their electrical conductivity.
Iohexol concentration most influenced CT number; volumetric ratios of 1:1000-1:1 produced 20 HU to over 3000 HU. CT numbers were weakly dependent on x-ray tube voltage, whereas contrast-to-noise ratio and streaking artifacts were somewhat dependent on tube output. An optimal ratio of iohexol in fluid was determined to be 1:50. There was no significant difference between the electrical impedances of doped and pure saline or D5W (p > 0.5, all cases).
A 1:50 ratio of iohexol in saline or D5W provides an optimal combination of increased visibility on CT without streaking artifacts.
本研究旨在确定生理盐水和 5%葡萄糖溶液（D5W）中碘造影剂的浓度，用于器官分离术，这是一种用于物理分离和保护热消融附近组织的技术。
共准备了 28 个样本，来自 1:1000-1:1 碘海醇或碘美普尔葡甲胺造影剂，分别在生理盐水或 D5W 中。对单独的样本或与均质肝模拟体模并列的样本进行 CT 成像，使用 80-120 kVp 和 10-300 mAs。从液体、背景空气、紧邻液体的体模以及远离液体的体模中测量平均 CT 值和噪声。通过液体和体模之间的对比噪声比确定可视性，通过体模中的相对噪声量化条纹伪影。使用多元线性回归分别拟合测量值，以确定在不产生条纹伪影的情况下增加可视化的最佳对比度与液体比值。还测试了造影剂和血液掺杂的生理盐水和 D5W，以确定这种掺杂是否改变了它们的电导率。
碘海醇浓度对 CT 值影响最大；1:1000-1:1 的体积比产生 20 HU 至超过 3000 HU。CT 值与 X 射线管电压弱相关，而对比噪声比和条纹伪影与管输出有些相关。确定最佳的液体中碘海醇比值为 1:50。掺杂和纯生理盐水或 D5W 的电阻抗没有显著差异（p > 0.5，所有情况）。
生理盐水或 D5W 中碘海醇的 1:50 比例提供了一种在 CT 上增加可视性而无条纹伪影的最佳组合。
