Simulations and Inversions in Photoacoustic Tomography for High Resolution Quantitative Biomedical Imaging

高分辨率定量生物医学成像光声断层扫描的模拟和反演

• 批准号: EP/E050980/1
• 负责人: Benjamin Cox
• 金额: $ 106.48万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE050980%2F1
• 关键词: Simulations; Inversions; Photoacoustic; Tomography; Resolution

One out of every three people in the UK develops cancer at some stage in their life, and one in four die from it, according to the Office for National Statistics.It is well known that the early detection of cancer improves the chances of survival. For instance, malignant melanoma is a type of skin cancer that causes five deaths per day in the UK, but patients diagnosed at an early stage, when the treatments are much more effective, have an excellent prognosis with a five-year survival rate greater than 95%. A practical and inexpensive technique that could easily be deployed in clinics and hospitals to detect cancers at an earlier stage than is currently possible would therefore immediately improve survival rates.In the longer term, a better understanding of the processes and pathways that lead to cancerous tumours would aid in the development of new treatments and drugs. One of the most successful approaches to understanding disease in the human body has been to study similar diseases in small animals such as mice. There is sufficient similarity between murine and human physiology, such as in the way the immune system works, that 'mouse models' have become a mainstay of medical research. In recent years, advances in the techniques used to identify genes and proteins involved in disease mechanisms, and the increased availability of transgenic mice, have led to a demand for high-resolution, in vivo, small animal imaging modalities that can reveal where, and at what level, specific genes or proteins are being expressed, or other biomolecules or drugs are accumulating.Photoacoustic tomography is a new, inexpensive imaging technique that can provide 3D images of biological soft tissue, and has the potential to resolve structures within the tissue as narrow as a human hair (< 100 microns). By detecting the presence of small capillaries within nascent tumours, it may be able to detect cancers at an earlier stage than is currently possible. Early skin and breast tumours, for example, may be detectable using this approach. Furthermore, by using contrast agents, molecular markers or 'reporter' genes, 3D in vivo images of small animals showing the concentrations of the biomolecules of interest to within a few cells could become a realistic possibility.Photoacoustic tomography can distinguish between different biomolecules or tissues because of differences in their optical absorption spectra, ie. their colour. Small ultrasonic pulses are generated when light is absorbed in the tissue by, for instance, blood or a molecular marker. By illuminating the tissue with a colour of light that is absorbed only by the desired target, then only that target will generate ultrasound. By recording the ultrasound over several detectors, its origin can be calculated, in much the same way as we determine the location of a car horn by the difference in the time of arrival of the sound at our two ears. In this way a 3D image of the target absorber can be formed.Photoacoustic tomography clearly has great promise and the benefits to patients, clinicians and researchers could be enormous. However, some remaining technical hurdles must be overcome before all the potential benefits can be fully realised. For example, the speed at which the ultrasound travels through the tissue is not the same everywhere and so results in blurred images. Perhaps the most important outstanding problem is that of producing separate images of two or more absorbing substances (blood and a contrast agent, say) when they are simultaneously present in the tissue.The research proposed here will investigate a number of different ways to overcome the remaining challenges and so realize the full potential of photoacoustic tomography as a tool both for clinical diagnosis and high resolution imaging in biomedicine and the life sciences.

根据英国国家统计局的数据，在英国，每三个人中就有一个在生命的某个阶段患上癌症，四个人中就有一个死于癌症。众所周知，早期发现癌症可以提高生存的机会。例如，恶性黑色素瘤是一种皮肤癌，在英国每天造成5人死亡，但在早期诊断的患者，当治疗更有效时，预后良好，五年生存率超过95%。因此，一种实用而廉价的技术，可以很容易地在诊所和医院部署，在比目前更早的阶段检测癌症，这将立即提高生存率。从长远来看，更好地了解导致癌症肿瘤的过程和途径将有助于开发新的治疗方法和药物。了解人体疾病最成功的方法之一是研究小鼠等小动物的类似疾病。在小鼠和人类的生理学之间有足够的相似性，例如在免疫系统的工作方式上，“小鼠模型”已经成为医学研究的支柱。近年来，用于鉴定涉及疾病机制的基因和蛋白质的技术的进步以及转基因小鼠的增加的可用性已经导致对高分辨率体内小动物成像模式的需求，所述成像模式可以揭示特定基因或蛋白质在何处以及在什么水平上被表达，或者其他生物分子或药物正在积聚。这是一种廉价的成像技术，可以提供生物软组织的3D图像，并有可能分辨组织内的结构，如人的头发一样窄（< 100微米）。通过检测新生肿瘤内小毛细血管的存在，它可能能够在比目前可能的更早的阶段检测癌症。例如，早期的皮肤和乳腺肿瘤可以通过这种方法检测出来。此外，通过使用造影剂、分子标记或“报告”基因，小动物的3D活体图像显示感兴趣的生物分子的浓度在几个细胞内可能成为现实的可能性。他们的颜色。当光在组织中被例如血液或分子标记吸收时，产生小的超声脉冲。通过用仅被所需目标吸收的颜色的光照射组织，则仅该目标将产生超声。通过几个探测器记录超声波，可以计算出它的起源，就像我们通过声音到达我们两耳的时间差来确定汽车喇叭的位置一样。通过这种方式，可以形成目标吸收体的3D图像。光声层析成像显然具有很大的前景，对患者，临床医生和研究人员的好处是巨大的。然而，在充分实现所有潜在利益之前，必须克服一些剩余的技术障碍。例如，超声波穿过组织的速度在各处并不相同，因此导致图像模糊。也许最重要的突出问题是产生两种或多种吸收物质的单独图像（血液和造影剂，说）当它们同时存在于组织中时。这里提出的研究将调查许多不同的方法来克服剩余的挑战，从而实现光声断层扫描作为生物医学中的临床诊断和高分辨率成像工具的全部潜力，生命科学

项目成果

Notice of Removal: Design of multi-frequency acoustic kinoforms

• DOI: 10.1109/ultsym.2017.8092645
• 发表时间: 2017-09
• 作者: Michael D. Brown;B. Cox;B. Treeby

Photoacoustic tomography in a reflecting cavity

反射腔中的光声断层扫描

• DOI: 10.1117/12.2003571
• 发表时间: 2013
• 作者: Cox B

On the adjoint operator in photoacoustic tomography

• DOI: 10.1088/0266-5611/32/11/115012
• 发表时间: 2016-11-01
• 期刊: INVERSE PROBLEMS
• 影响因子: 2.1
• 作者: Arridge, Simon R.;Betcke, Marta M.;Treeby, Brad E.
• 通讯作者: Treeby, Brad E.

Experimental study of beam distortion due to fiducial markers during salvage HIFU in the prostate.

• DOI: 10.1186/s40349-018-0109-3
• 发表时间: 2018
• 期刊: Journal of therapeutic ultrasound
• 作者: Bakaric M;Martin E;S Georgiou P;T Cox B;Payne H;E Treeby B
• 通讯作者: E Treeby B

Single pulse illumination of multi-layer photoacoustic holograms for patterned ultrasound field generation

用于图案化超声场生成的多层光声全息图的单脉冲照明

• DOI: 10.1109/ultsym.2016.7728755
• 发表时间: 2016
• 作者: Brown M