利用视网膜功能测量仪对眼底进行结构成像来直接观察体内丰富的循环系统,并对视网膜的血氧饱和度及血管直径进行无创、定量的功能性成像测量。对糖尿病患者和健康人群进行视网膜功能成像并作定量比较分析,结果表明,在糖尿病患者中,视网膜动脉血氧饱和度相比健康人群有显著性提高,视网膜动静脉血氧饱和度差值有显著性增大,视网膜黄斑中心凹无灌注区面积也有显著增大。此外,在糖尿病患者和健康人群中,视网膜动静脉的直径均存在差异,且静脉直径总大于动脉直径。研究结果表明通过视网膜功能成像可以检测糖尿病患者的视网膜氧代谢和灌注率等参数的临床变化,帮助医生更好地观察、评估糖尿病患者视网膜微血管的病理改变,并在糖尿病患者眼科并发症的早期诊断和预后评估方面具有一定的应用潜力。

The Monte Carlo method is a versatile simulation algorithm to model the propagation of photons inside the biological tissues. It has been applied to the reconstruction of the fluorescence molecular tomography (FMT). However, such method suffers from low computational efficiency, and the time consumption is not desirable. One way to solve this problem is to introduce a priori knowledge which will facilitate iterative convergence. We presented an in vivo simulation environment for fluorescence molecular tomography (ISEFMT) using the Monte Carlo method to simulate the photon distribution of fluorescent objects and their sectional view in any direction quantitatively. A series of simulation experiments were carried out on different phantoms each with two fluorescent volumes to investigate the relationship among fluorescence intensity distribution and the excitation photon number, the locations and sizes of the fluorescence volumes, and the anisotropy coefficient. A significant principle was discovered, that along the direction of the excitation light, the fluorescent volume near the excitation point will provide shelter effect so that the energy of the fluorescent volume farther away from the excitation point is relatively lower. Through quantitative analysis, it was discovered that both the photon energy distribution on every cross section and the fluorescence intensity distributed in the two volumes exhibit exponential relationships. The two maximum positions in this distribution correspond to the centers of fluorescent volumes. Finally, we also explored the effect of the phantom coefficients on the exponential rule, and found out that the exponential rule still exists, only the coefficient of the exponential rule changed. Such results can be utilized in locating the positions of multiple fluorescent volumes in complicated FMT reconstruction involving multiple fluorescent volumes. Thus, a priori knowledge can be generalized, which would accelerate the reconstruction of FMT and even other images.

The photoacoustic tomography by using the handheld probe has a great potential in clinical breast imaging. However, the shape of the probe limits the choice of light delivery in this setup. In this letter, we study two commonly used illumination types for handheld probe: bright-field illumination and dark-field illumination. Our results demonstrate several parameters have important impact on the photon fluence in deep breast tissue. The results will help to optimize the design of the photoacoustic breast imaging system with a handheld probe.

碲锌镉(CdZnTe)半导体材料具有探测效率高、能量分辨率高和体积小重量轻的特点, 是公认的最有希望成为下一代伽马射线探测装置的材料。然而, 空穴俘获导致的电荷收集不完全限制了碲锌镉半导体探测器的性能。解决空穴俘获最有效的方法是单极型探测器技术。文章首先简要介绍半导体探测器中电荷收集的相关理论, 然后重点阐述单极型探测器技术的实现方法, 包括各种电极的结构设计原理、典型的探测器原型机介绍、性能特点及其结构设计的优缺点。最后简要展望了碲锌镉半导体探测器未来的发展方向。

The murine model of hindlimb ischemia is extensively used in studies on the physiology and pathology of ischemia and angiogenesis. Traditional non-invasive evaluation methods, such as laser or ultrasound blood flow perfusion imaging and micro-CT angiography, are limited either by low resolution or toxic exogenous agents. Relying on intrinsic high optical absorption contrast, we conduct label-free imaging of subcutaneous blood vasculature in the hindlimb of murine models by photoacoustic microscopy (PAM). The angiogenesis induced by ischemia in the hindlimb is successfully observed at high resolution in vivo and non-invasively. PAM is a potentially powerful imaging method for studying ischemic diseases and resultant angiogenesis.

光声分子影像是近期发展起来的新型无创在体影像技术。该技术结合了光声层析成像和分子影像，具有成像深度深、分辨率高和特异性强的优点。光声分子影像已经被广泛用于活体动物实验中，在对一些恶性肿瘤和炎症的检测中获得了令人振奋的结果。重点介绍了光声分子影像的机制和研究现状，并对其应用前景进行展望。

皮肤影像学是利用现代成像技术手段对皮肤病进行无创、原位、动态、实时诊断的一门新兴技术学科。在过去十几年里作为医学影像学分支的皮肤影像学取得了长足的进步,包括皮肤镜等多种光学成像技术已经被广泛应用于临床疾病诊断。主要介绍了皮肤镜、皮肤共聚焦、多光子成像、光学相干层析成像以及光声成像等技术在皮肤影像学中的发展和应用。这5种技术能够实现原位、在体、实时的皮肤成像，可对可疑部位进行重复检查，并能不同程度地实现皮下组织的无损成像，为临床诊断提供了客观的评价依据。不断发展的皮肤影像学，与皮肤组织病理学相互促进、相互补充,势必将带动现代皮肤病学的飞跃发展。

可变形反射镜是自适应光学系统的核心组成部分之一, 在人眼像差的检测与校正等方面得到了广泛的应用。目前自适应光学系统最常采用的变形镜主要有两种：微加工薄膜变形镜和压电式变形镜。基于两者结构原理的不同, 它们在自适应光学系统中的表现也存在着差异。采用59通道微加工薄膜变形镜和37通道压电式变形镜进行对比实验。利用同一闭环自适应光学系统针对4阶以内的常见像差(包括散光、彗差、三叶差、球差)观察两者的泽尼克系数生成情况。结果表明, 目标值较小时, 微加工薄膜变形镜和压电式变形镜的泽尼克系数实际值误差都比较小; 目标值增大时, 压电式变形镜可以比微加工薄膜变形镜更接近理想值。

引入了由非球面角膜和晶状体组成的模型眼, 采用ZEMAX软件进行光线追迹, 为无晶状体眼的人工晶状体的设计提供理论依据。计算表明, 球差是影响人眼像质的关键因素。一般对于正常眼来说, 晶状体的负球差可以部分补偿角膜的正球差, 从而降低整个人眼光学系统的球差, 以保证较好的视觉功能。随着年龄的增长, 晶状体的球差逐渐由负球差转变为正球差, 这样晶状体对人眼整体像差的补偿作用就会减小甚至消失。为了减小球差的影响, 人工晶状体的表面结构需采用非球面设计。当其非球面系数Q值固定时, 人工晶状体的球差主要受到其本身的屈光度的影响。要想优化整个人眼光学系统的球差, 人工晶状体必须要引入一个负的Q值。