P239 X-ray phase contrast imaging for staging oesophageal tumours: preliminary results from the VIOLIN study
P239 X-ray phase contrast imaging for staging oesophageal tumours: preliminary results from the VIOLIN study
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P239 用于食管肿瘤分期的 X 射线相差成像：VIOLIN 研究的初步结果
DOI：
10.1136/gutjnl-2020-bsgcampus.313
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Wolfson P
中科院分区：
文献类型：
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作者：
Wolfson P
食管癌是全球第七大常见癌症死亡原因。局部食管癌的放射分期不准确。CT目前依靠x射线的衰减来产生对比。软组织具有非常相似的衰减特性，因此产生的对比度最小。x射线相衬成像（XPCI）利用x射线穿过组织时的折射而不是衰减，从而提供更高的软组织对比度。该技术可调至约10 μ m的分辨率。这可以很容易地评估疾病的浸润程度。我们的目的是使用XPCI对食管癌切除术标本进行成像，以评估食管癌的病理肿瘤和淋巴结分期。方法经伦理批准，从食管癌手术患者中获得10例食管癌切除术标本。包括鳞状癌和腺癌。标本在福尔马林中固定12小时。将缝合线穿过组织，使CT切片和组织学切片能够共同匹配。对于一些扫描，然后用分级乙醇将组织脱水4.5小时至72小时，然后进行成像。使用40 kV、20 mA的Rigaku (MicroMax 007) x射线源；50µm像素大小的检测器；样品和检测器掩模由石墨衬底与金覆盖。采用边缘照明技术生成相衬。我们使用MATLAB®软件重建图像。返回标本进行临床组织病理学评估，以便将H&E玻片与CT图像进行相关性分析。结果我们对10个食管切除术样本进行了25次扫描，并将其与组织学相关联。福尔马林扫描的样本未能显示足够的食道层之间的对比，从而无法实现肿瘤的可视化和分期。用乙醇浸润组织可以获得更好的图像对比度。我们可以很容易地在重建的CT图像中识别粘膜、粘膜下层和两层肌肉。我们还发现肿瘤通过组织层浸润并破坏了正常的食管形态（图1）。这在组织学上得到了证实，并且可以被不了解病理分期的放射科医生识别出来。这是XPCI首次用于人类食管组织成像。我们已经证明了该技术的可行性和获得高分辨率图像的可能性，这些图像模拟组织学，并具有展示三维结构的额外好处。
IntroductionOesophageal cancer is the 7th commonest cause of cancer death worldwide. Radiological staging of local oesophageal cancer is inaccurate. CT currently relies on attenuation of x-rays to generate contrast. Soft tissues have very similar attenuation properties so minimal contrast is generated.X-ray phase contrast imaging (XPCI) uses refraction of x-rays as they pass through tissue instead of attenuation and provides much higher soft tissue contrast. This technology can be tuned to a resolution of approximately 10 µm. This may allow for easy assessment of extent of disease infiltration.We aimed to use XPCI to image oesophagectomy specimens to assess pathological tumour and nodal stage for oesophageal cancerMethodsFollowing ethical approval, 10 oesophagectomy specimens were obtained from patients having surgery for oesophageal cancers. These included both squamous and adenocarcinomas.Specimens were fixed in formalin for 12 hours. Sutures were placed through tissue to enable co-registration between CT slices and histology sections. For some scans, tissue was then dehydrated with graded ethanol for between 4.5 hours and 72 hours before being imaged. A Rigaku (MicroMax 007) xray source was used at 40 kV and 20 mA; a detector with 50µm pixel size; and sample and detector masks made of graphite substrate with gold overlay. Phase contrast was generated using edge illumination technique.We reconstructed the images using MATLAB® software. Specimens were returned for clinical histopathological assessment allowing correlation between H&E slides and CT images.ResultsWe have performed 25 scans on 10 oesophagectomy samples and correlated them with histologyScans of samples in formalin failed to show adequate contrast between oesophageal layers to enable tumour visualisation and staging. Infiltrating the tissue with ethanol led to much better image contrast.We could easily identify mucosa, submucosa and both layers of muscle in reconstructed CT images. We also identified tumour infiltration through tissue layers and destruction of normal oesophageal morphology (figure 1). This was confirmed histologically and could be recognised by radiologists blinded to pathological stagingThis is the first time that XPCI has been used to image human oesophageal tissue. We have demonstrated the feasibility of the technique and the possibility of obtaining high resolution images which mimic histology with the extra benefit of demonstrating three dimensional structure.