X-ray imaging has proved invaluable in medical diagnoses and non-destructive testing (NDT) in the past century. However, there remain two major limitations: radiation harm and inaccessibility to the sample. A recent imaging modality, X-ray induced acoustic computed tomography (XACT), allows a novel solution. In XACT, x-ray induced excitation causes localized heating (<mK) and thermoelastic expansion. This induces a detectable ultrasonic emission, thereby enabling imaging. XACT has the potential to enable low-dose, fast, 3D imaging requiring only single side access. We discuss the fundamentals of XACT and summarize milestones in its evolution over the past several years since its first demonstration using a Medical Linear Accelerator. We highlight XACT’s potential applications in biomedical imaging and NDT, and discuss the latest advanced concepts and future directions.

上个世纪，X 射线成像已被证明在医学诊断和无损检测 (NDT) 方面具有无价的价值。然而，仍然存在两个主要限制：辐射危害和无法获取样品。最近的成像方式 X 射线诱导声学计算机断层扫描 (XACT) 提供了一种新颖的解决方案。在 XACT 中，X 射线诱导激发会导致局部加热 (<mK) 和热弹性膨胀。这会引起可检测的超声波发射，从而实现成像。XACT 有潜力实现仅需要单侧访问的低剂量、快速 3D 成像。我们讨论了 XACT 的基本原理，并总结了自首次使用医用线性加速器进行演示以来过去几年其发展的里程碑。我们重点介绍 XACT 在生物医学成像和无损检测方面的潜在应用，并讨论最新的先进概念和未来方向。