PLoS ONE：心跳紊乱检测有新法 X射线可生成高分辨三维图像

心脏三维图显示控制心脏节律的组织纤维。

据物理学家组织网日前报道，英国曼彻斯特大学科学家开发出一种新的X射线技术，可显示心脏肌肉组织纤维是否有节律跳动，有助于未来提高医疗手段及医学深入研究。

心脏需要在规律节奏下保持稳定的血液循环，以维持身体各个部位的血液供给。它通过协调肌肉组织的行动循环血液，并指挥组织进行必要的分送电波以触发每一次心跳。但科学家们一直无法生成高分辨率的三维图像，用以充分识别控制心脏组织节律的网络。

研究小组用碘对心脏组织进行处理，以突出不同部分，然后使用微CT扫描仪生成三维图像，从中科学家能够清楚地识别在这一区域产生的电波触发活动。新的三维图像可有助于进一步了解人体内心跳是如何被扰乱的，帮助医务人员开发出减少纤维性颤动风险的办法，改善心脏肌肉收缩混乱和身体周围血液循环缺乏节奏等状况。

曼彻斯特大学老龄化和慢性疾病研究所乔纳森-贾维斯博士说：“这些新的解剖学上的详细图像，可以提高未来计算机心脏模型的准确性，并帮助我们了解正常和不正常的心脏节律是如何产生的。三维成像将使我们对心脏传导系统有更透彻的认识，并且该方式还会给心脏疾病的治疗带来改变。”

贾维斯说：“基于这些高保真图像的计算机模型，将有助于我们理解心脏大小、血液供应或心脏病发作后疤痕等变化如何使心律变得脆弱，例如，心脏外科医生主要关注的问题之一就是修复畸形心脏以避免损害组织分送电波，如果他们获得了对畸形心脏传导组织的三维图像，那么就有可能在手术前了解其中哪里的传导组织出现了状况。”(生物谷：Bioon.com)

doi: 10.1371/journal.pone.0035299
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Contrast Enhanced Micro-Computed Tomography Resolves the 3-Dimensional Morphology of the Cardiac Conduction System in Mammalian Hearts

MRobert S. Stephenson1, Mark R. Boyett2, George Hart1, Theodora Nikolaidou2, Xue Cai2, Antonio F. Corno3, Nelson Alphonso4, Nathan Jeffery1, Jonathan C. Jarvis

The general anatomy of the cardiac conduction system (CCS) has been known for 100 years, but its complex and irregular three-dimensional (3D) geometry is not so well understood. This is largely because the conducting tissue is not distinct from the surrounding tissue by dissection. The best descriptions of its anatomy come from studies based on serial sectioning of samples taken from the appropriate areas of the heart. Low X-ray attenuation has formerly ruled out micro-computed tomography (micro-CT) as a modality to resolve internal structures of soft tissue, but incorporation of iodine, which has a high molecular weight, into those tissues enhances the differential attenuation of X-rays and allows visualisation of fine detail in embryos and skeletal muscle. Here, with the use of a iodine based contrast agent (I2KI), we present contrast enhanced micro-CT images of cardiac tissue from rat and rabbit in which the three major subdivisions of the CCS can be differentiated from the surrounding contractile myocardium and visualised in 3D. Structures identified include the sinoatrial node (SAN) and the atrioventricular conduction axis: the penetrating bundle, His bundle, the bundle branches and the Purkinje network. Although the current findings are consistent with existing anatomical representations, the representations shown here offer superior resolution and are the first 3D representations of the CCS within a single intact mammalian heart.