Single atom imaging

对于老龄化人口，医学成像在诊断癌症等严重疾病方面越来越重要。两种重要的技术严重依赖于引入体内的放射性示踪剂。这些是正电子发射断层扫描（PET）和单光子发射计算机断层扫描（SPECT）。前者涉及将β衰变同位素如F-18引入体内，这些同位素被特定器官和癌症选择性地吸收。在这种同位素的衰变中，两条伽马射线几乎背靠背地发射。源的位置，然后建立从拦截的一个非常大的合奏这些轨道。我们提出了一个新的医学成像概念，建立在PET成像概念的基础上，但它有可能定位单个放射性原子。这是因为同位素建议，Tc-92，衰变由连续的时间顺序的伽马射线。我们可以确定这些发射的伽马射线的方向，从而确定发射点。这与标准PET成像非常不同，因为我们通过统计方法定位一个原子而不是一个非常大的系综。这可以提供前所未有的灵敏度和/或使用非常低剂量的放射性示踪剂的能力，对患者有很大的益处。这种新技术也可能在工业流程中有重要的应用。我们打算通过模拟进行可行性研究。这将为新型扫描仪指定最佳几何形状，并确定可实现的灵敏度。

For an ageing population, medical imaging is increasingly important in diagnosing serious conditions such as cancer. Two important techniques make heavy reliance on radioactive tracers introduced into the body. These are positron emission tomography (PET) and single-photon emission computed tomography (SPECT). The former relates to the introduction of beta-decaying isotopes like F-18 into the body which are selectively taken up by specific organs and cancers. In the decay of this isotope, two gamma rays are emitted near back to back. The location of the source is then established from the interception of a very large ensemble of these tracks. We have come up with a new concept for medical imaging, building on the PET imaging concept, but which has the potential to locate a single radioactive atom. This is because the isotope suggested, Tc-92, decays by successive time-ordered gamma rays. We can determine the direction of these emitted gamma rays and hence determine the point of emission. This is very different to standard PET imaging as we locate one atom and not a very large ensemble via a statistical approach. This could offer unprecedented sensitivity and/or ability to use very low doses of radioactive tracer with strong benefits to the patient. This new technique could also have important applications to industrial flow processes. We intend to carry out a feasibility study by performing simulations. This will specify the best geometry for a novel scanner and determine the sensitivity achievable.