Division of Pediatric Radiology, Department of Radiology, Medical University Graz, Auerbruggerplatz 34, Graz, Austria.
Eur J Radiol. 2013 Jul;82(7):1091-7. doi: 10.1016/j.ejrad.2011.12.001. Epub 2012 Jan 9.
The introduction of helical computer tomography (CT) and further progress to multi-slice CT enabled new applications. Most recent developments like the 320-row detector facilitate volume CT, which avoids the over-beaming effect of helical scanning. The 320-row multi-slice detector CT (MDCT) is based on a 16cm detector; a special acquisition mode allows reconstructing 640 slices from these 16cm. The shortest tube rotation time is in cardiac mode 0.35s, otherwise 0.4s and 0.5s used. At 0.5s the machine already reaches the maximum numbers of sub-second projections. Scan modes can be volume, helical and single slice mode. For image acquisition all dose savings technologies like variable tube position for scano-view, active collimation, automated exposure control, bolus and ECG tracking are available. Additionally special acquisition and post-processing techniques like head and body perfusion CT are ready for use on the console. For image reconstruction properties like filtered back projection as well as the latest development of iterative algorithms, an appropriate number of kernels and multi-planar reconstruction in all directions from the volume data at every increment are available. Volume CT allows sub second scanning of 16cm z-coverage which, however, makes administration of intravenous contrast medium to "hit or miss" event. The aim of this paper is to present the application of volume CT to body scanning in children. Representative examples of neck, cardiac and skeletal investigations are given.
螺旋计算机断层扫描（CT）的引入和进一步发展到多排 CT 使得新的应用成为可能。最近的发展，如 320 排探测器，促进了容积 CT 的发展，避免了螺旋扫描的过度照射效应。320 排多层探测器 CT（MDCT）基于 16cm 探测器；一种特殊的采集模式可以从这些 16cm 中重建 640 层。最短的管旋转时间是在心脏模式下为 0.35s，否则为 0.4s 和 0.5s。在 0.5s 时，机器已经达到了最大数量的亚秒投影。扫描模式可以是容积、螺旋和单切片模式。对于图像采集，所有节省剂量的技术，如用于扫描视野的可变管位置、主动准直、自动曝光控制、团注和 ECG 跟踪，都可用。此外，头部和身体灌注 CT 等特殊采集和后处理技术也可在控制台使用。对于图像重建，如滤波反投影以及迭代算法的最新发展，在每次增量的容积数据中，都可以使用适当数量的内核和多平面重建。容积 CT 允许对 16cm z 覆盖范围进行亚秒扫描，然而，这使得静脉注射造影剂的管理成为“碰运气”的事件。本文的目的是介绍容积 CT 在儿童身体扫描中的应用。给出了颈部、心脏和骨骼检查的代表性示例。
