Miles Kenneth A, Young Helen, Chica Sandra L, Esser Peter D
Brighton & Sussex Medical School, University of Sussex, Falmer, Brighton, BN1 9PX, UK.
Eur Radiol. 2007 Apr;17(4):919-26. doi: 10.1007/s00330-006-0424-x. Epub 2006 Sep 29.
The purpose of the study was to perform phantom studies to assess the impact of computed tomography (CT) system variability on quantitative measurements of contrast enhancement. A phantom containing tubes of contrast material at dilutions of 120, 1:35, 1:50, 1:100 and 1:200 arranged in air or water was imaged using 11 CT systems at 9 institutions. All systems had undergone routine calibration against air and water in accordance with the manufacturers' recommendations. For a given tube voltage, the relationship between the iodine concentration and CT attenuation value on a single system varied by 17 to 24% over 46-48 weeks. The coefficients of variance for iodine calibration factors across different CT systems were 8.9% in air and 5.1% in water. Calibration of individual CT systems for iodine response is required to allow comparison of quantitative measurements of contrast enhancement across different institutions. Using the iodine calibration factor to express contrast enhancement as iodine concentration would facilitate the universal application of diagnostic enhancement thresholds, especially if the necessary calculations were performed by software installed on the CT console.
本研究的目的是进行体模研究，以评估计算机断层扫描（CT）系统变异性对造影剂增强定量测量的影响。使用9家机构的11台CT系统，对一个包含稀释度为120、1:35、1:50、1:100和1:200的造影剂管且置于空气或水中的体模进行成像。所有系统均已按照制造商的建议针对空气和水进行了常规校准。对于给定的管电压，单个系统上碘浓度与CT衰减值之间的关系在46 - 48周内变化了17%至24%。不同CT系统之间碘校准因子的方差系数在空气中为8.9%，在水中为5.1%。需要对各个CT系统进行碘响应校准，以便比较不同机构之间造影剂增强的定量测量结果。使用碘校准因子将造影剂增强表示为碘浓度将有助于诊断增强阈值的普遍应用，特别是如果必要的计算由CT控制台安装的软件执行时。
