Variability in Absolute Apparent Diffusion Coefficient Values across Different Platforms May Be Substantial: A Multivendor, Multi-institutional Comparison Study
Variability in Absolute Apparent Diffusion Coefficient Values across Different Platforms May Be Substantial: A Multivendor, Multi-institutional Comparison Study
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DOI：
10.1148/radiol.2492071681
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发表时间：
2008-11-01
期刊：
影响因子：
19.7
通讯作者：
Shibata, Eri
中科院分区：
文献类型：
--
作者：
Sasaki, Makoto;Yamada, Kei;Shibata, Eri
目的：为了确定是否以及在何种程度上绝对表观扩散系数（ADC）值不同的成像仪，供应商，场强，和intramimager conditions.Materials和方法：知情同意和机构审查委员会的批准。使用四个不同供应商提供的10台磁共振（MR）成像仪，在1.5 T和3.0 T下从七个机构的12名健康志愿者获得了参数几乎相同的扩散加权（DW）图像。从各向同性DW图生成ADC图，并使用内部软件生成B值为0 sec/mm（2）的图像。结果：同一厂家生产的磁共振成像仪在1.5 T和3.0 T时，灰、白色物质的绝对ADC值相差很大，分别为4%~ 9%。除一家供应商外，1.5 T下的供应商间变异性高达7%。此外，有大量的intramimager变异性，高达8%，取决于线圈系统在某些imagers.Conclusion：有显着的变化，ADC值取决于线圈系统，成像器，供应商，和磁场强度用于MR成像。相对ADC值可能比绝对ADC值更适合于评价多中心急性缺血性卒中试验中入组患者的弥散异常。(c)RSNA，2008年
Purpose: To determine whether and to what degree absolute apparent diffusion coefficient (ADC) values vary between different imagers, vendors, field strengths, and intraimager conditions.Materials and Methods: Informed consent and institutional review board approval were obtained. Diffusion-weighted (DW) images with nearly identical parameters were obtained at 1.5 and 3.0 T from 12 healthy volunteers at seven institutions by using 10 magnetic resonance (MR) imagers provided by four different vendors. ADC maps were generated from isotropic DW maps, and images with a b value of 0 sec/mm(2) were generated by using in-house software. The mean pixel values for the brain tissues were calculated for evaluating the differences among coil systems, imagers, vendors, and magnetic field strengths.Results: The absolute ADC values of gray and white matter from the same vendor varied substantially: 4%-9% at 1.5 and 3.0 T. With the exception of one vendor, the intervendor variability at 1.5 T was as high as 7%. Moreover, there was substantial intraimager variability, up to 8%, depending on the coil systems in certain imagers.Conclusion: There is significant variability in ADC values depending on the coil systems, imagers, vendors, and field strengths used for MR imaging. The relative ADC values may be more suitable than absolute ADC values for evaluating diffusion abnormalities in patients enrolled in multicenter acute ischemic stroke trials. (c) RSNA, 2008