HEXITEC: Translation grant. The application of colour X-ray imaging

X射线彩色成像有可能可视化的物理和化学性质的一个标本空间内解决了三维密度对比度图像。例如，X射线彩色成像可以识别航空航天工业中使用的复杂制造部件是否可能因裂纹或疲劳应力而失效;或者手提箱是否含有非法物质，如塞姆汀或可卡因;或者活检样本是否含有正常或异常组织。全X射线彩色成像系统需要能量敏感探测器，这些探测器被分成小的离散像素，并且可以阻止高能X射线。此外，由于我们要寻找的是非常微弱的信号，因此来自样品的散射辐射通常必须非常精细地准直。五年前，既没有合适的探测器材料，也没有散射控制系统。后一个问题得到了解决（通过EPSRC的另一笔赠款），但世界上任何地方都没有可靠的探测器材料来源。英国缺乏生产合适探测器系统的技术专长，导致了HEXITEC联盟（高能X射线成像技术; www.hexitec.co.uk）的形成。HEXITEC开发了探测器系统制造的每个阶段，最近展示了其第一个20 × 20像素的原型，作为将于2010年初交付的完整80 × 80设备的先驱。我们现在正在申请资金，以便在三个工作方案中将HEXITEC开发的技术带入下一个发展阶段，这些工作方案涵盖不同发展阶段的四种广泛应用。工作包1：用于材料成像的荧光层析成像我们将使用HEXITEC开发的80 x 80像素探测器系统用于这两种目的。荧光断层扫描是基于标准的吸收方法，其中样品在光束中旋转，并且许多部分在数学上重新组合以给出3D图像。这里的关键区别在于，我们将能够在谨慎的能量范围内做到这一点。我们将获得可以在800 eV范围或更好范围内选择能量的切片。我们将提供一个基于实验室的系统，以产生特定元素的图像。工作包2：TEDDI在材料鉴定和安全扫描中的应用TEDDI方法使用散射（非直接透射）X射线，其中包含样品内每个点的晶体结构信息。TEDDI使用多个平行准直器来获得其空间分辨率，并且样品不需要以与标准层析成像相同的方式旋转。我们将制作一个基于实验室的TEDDI系统，以在1x 10 -3 mm 3的空间尺度上识别复杂样品的每个部分的特定材料。我们还将与我们的合作伙伴Kromek有限公司谁最初脱离了达勒姆大学物理系。他们正在开发用于机场威胁识别的扫描仪。我们将与HEXITEC探测器共同开发TEDDI技术，根据相干散射信号识别材料。这是一个比依靠纯粹吸收信息可靠得多的测试。结合现有的方法，可以显着降低虚警率。工作包3：组织活检许多软组织类型具有非常相似的衍射图案，特别是那些具有高含水量的软组织，然而，某些类型的乳腺癌已被证明是非常容易通过能量色散衍射方法与正常组织区分开的。我们打算与皇家苏里和马斯登医院共同开发一种X射线组织活检模式。通过使用HEXITEC检测器系统，我们将获得有关特定组织类型的独特信息，这将大大减少假阳性的数量。这是一个至关重要的目标，因为错误的诊断会给患者带来大量不必要的不适和痛苦。

X-ray colour imaging has the potential to visualise the physical and chemical nature of a specimen spatially resolved within a three dimensional density contrast image. X-ray colour imaging makes it possible to recognise, for example, whether complex manufactured components used in the aerospace industry are likely to fail through cracks or fatigue stress; or whether a suitcase contains illicit substances such as semtex or cocaine; or whether a biopsy sample contains normal or abnormal tissue. A full X-ray colour imaging system requires energy sensitive detectors that are divided into small discrete pixels and can stop high energy X-rays. In addition the scattered radiation from the sample often has to be very finely collimated because we are looking for very weak signals. Five years ago neither suitable detector material nor scatter control systems were available. The latter problem was addressed (by another EPSRC grant) but there was no reliable source of detector material anywhere in the world. The lack of technological expertise within the UK to produce suitable detector systems led to the formation of the HEXITEC consortium (High Energy X-ray Imaging Technology; www.hexitec.co.uk). HEXITEC has developed every stage of detector system manufacture and has very recently demonstrated its first 20 by 20 pixel prototype as a forerunner of a full 80 by 80 device that will be delivered early in 2010. We are now requesting funds to take the HEXITEC developed technology to the next stage of development in three work programmes covering four broad applications at different stages of development. Work package 1: Fluorescence tomography for materials imaging We will use the 80 by 80 pixel detector systems developed by HEXITEC for both purposes. Fluorescence tomography is based on a standard absorptive method where the sample is rotated in the beam and many sections are mathematically recombined to give a 3D image. The crucial difference here is that we will be able to do this in discreet energy ranges. We will obtain slices that can be energy selected in 800eV ranges or better. We will deliver a lab based system to produce element specific images. Work package 2: The appliaction of TEDDI to materails identificatication and security scanningThe TEDDI method uses scattered (not directly transmitted) X-rays which contain information on the crystal structure at each point within the sample. TEDDI uses multiple parallel collimators to obtain its spatial resolution and the sample does not need to be rotated in the same way as standard tomography. We will make a lab based TEDDI system to identify specific materials at each part of a complex sample on a 1x10-3 mm3 spatial scale. We will also work with our partners Kromek ltd who originally spun out of the Durham University Physics Department. They are developing scanners for threat identification at airports. We will jointly develop the TEDDI technology with HEXITEC detectors to recognise materials based on their coherent scattered signals. This is a much more reliable test than relying on purely absorptive information. In conjunction with existing methods the false alarm rate can be significantly reduced. Work package 3: Tissue BiopsyMany soft tissue types have very similar diffraction patterns especially those with a high water content, however certain types of breast cancers have been shown to be quite easily distinguishable from normal tissue by energy dispersive diffraction methods. We intend to develop, jointly with the Royal Surry and Marsden hospitals, an X-ray tissue biopsy modality. By using HEXITEC detector systems we will obtain unique information about specific tissue types that will significantly reduce the number of false positives. This is a vital aim because a false diagnosis leads to great deal of unnecessary discomfort and distress to the patient.