THE UNRELIABILITY OF CT-NUMBERS AS ABSOLUTE VALUES
THE UNRELIABILITY OF CT-NUMBERS AS ABSOLUTE VALUES
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DOI：
10.2214/ajr.139.3.443
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发表时间：
1982-01-01
影响因子：
5
通讯作者：
HATTERY, RR
中科院分区：
文献类型：
--
作者：
LEVI, C;GRAY, JE;HATTERY, RR
通过在模拟常规身体CT扫描中遇到的各种条件下在5台CT扫描仪上扫描标准体模，检查CT [计算机断层扫描]数值作为绝对值的使用。大多数扫描仪之间的绝对CT值存在显著差异（只有1台扫描仪产生的水的CT值等于零）。同一制造商和型号的两台扫描仪之间的绝对CT值存在显著差异。单个体模扫描中的CT数量存在显著差异，取决于扫描中的位置，并且这种变化的格式在不同扫描仪之间并不恒定。根据各种物理因素（例如，千伏、扫描孔径中的体模方向和体模在扫描孔径中的位置）。研究结果表明，对于给定的组织类型，仅由于扫描仪性能，观察到的CT值范围很广，如果将绝对CT值用于诊断，则用户必须记录这些机器相关变化小于认为显著的差异。
The use of CT [computed tomography] numbers as absolute values was examined by scanning a standard phantom on 5 CT scanners under a variety of conditions simulating those encountered in routine body CT scanning. There are significant differences in absolute CT numbers between most scanners (only 1 scanner produced CT numbers that were equal to zero for water). There are significant differences in absolute CT numbers between two scanners of the same manufacturer and model that were examined. There is a significant difference in CT numbers in a single phantom scan, dependent on location in the scan, and the format of this variability is not constant from one scanner to another. There may be a significant difference in absolute CT numbers, depending on various physical factors (e.g., kilovoltage, phantom orientation in scan aperture and position of the phantom in the scan aperture). The findings suggest that there is a wide range of CT numbers observed for a given tissue type as a result of scanner performance alone, and that if absolute CT numbers are to be used for diagnosis the user must document that these machine-related variations are less than the differences thought to be significant.