Department of Radiology and Medical Imaging, Ghent University Hospital, Ghent, Belgium. louke.delrue @ uzgent.be
Pancreatology. 2011;11(6):588-94. doi: 10.1159/000334547. Epub 2012 Jan 11.
Multidetector CT is a valuable technique for diagnosis/staging in several pancreatic pathologies. Diagnosis is usually based on tissue density measurements. Recently, newer functional CT techniques have been introduced. The aim of this study was to assess variability in perfusion and dual-energy CT data, and to compare these data with density measurements in the pancreas of a healthy population.
Two groups were included: 20 patients underwent perfusion CT imaging, and 10 patients were scanned using a dual-energy protocol. In both groups, tissue density [Hounsfield units (HU)] was measured in the pancreatic head, body and tail. Functional data were calculated (blood flow/blood volume in the perfusion CT group, iodine concentration in the dual-energy group), and variability was assessed.
Density measurements were comparable for the perfusion and dual-energy CT groups, and ranged from 14 to 60 HU. Maximal enhancement differences between the head/body/tail of the pancreas ranged between 2 and 21 HU. Considerable variability was observed, both in density measurements (ranging from 3 to 34%) and in functional parameters (mean variability in perfusion CT parameters blood flow and blood volume was 21.3 and 10% respectively; mean variability in dual-energy iodine-mapping results was 24.4%).
This study demonstrated the presence of important intraindividual variability in pancreatic tissue contrast enhancement, regardless of the CT technique used. Considering the variability observed in this study, the use of cut-off values to characterize pancreatic pathologies seems troublesome, and morphologic primary and secondary changes will remain important, even when using novel functional imaging techniques. and IAP.
多排螺旋 CT 是多种胰腺病变诊断/分期的有价值的技术。诊断通常基于组织密度测量值。最近，引入了新的功能 CT 技术。本研究旨在评估健康人群胰腺灌注和双能 CT 数据的变异性，并将这些数据与密度测量值进行比较。
包括两组：20 例患者行灌注 CT 成像，10 例患者行双能协议扫描。在两组中，均在胰头、体和尾测量组织密度[亨氏单位（HU）]。计算功能数据（灌注 CT 组的血流量/血容量，双能组的碘浓度），并评估变异性。
灌注和双能 CT 组的密度测量值具有可比性，范围为 14 至 60 HU。胰头/体/尾之间的最大增强差异范围为 2 至 21 HU。观察到相当大的变异性，包括密度测量值（范围为 3 至 34%）和功能参数（灌注 CT 参数血流量和血容量的平均变异性分别为 21.3%和 10%；双能碘图结果的平均变异性为 24.4%）。
本研究表明，无论使用何种 CT 技术，胰腺组织对比增强的个体内变异性均较大。考虑到本研究中观察到的变异性，使用临界值来描述胰腺病变似乎很麻烦，即使使用新的功能成像技术，形态学原发性和继发性变化也将仍然很重要。和 IAP。
