Quantitative magnetic resonance imaging of the prostate at 7 tesla

学生战略优先领域：医学物理学关键词：前列腺、核磁共振、7T、射频线圈这个博士项目将与英国皇家医学研究院资助的一项重大新计划相联系，该计划将提供3800万GB资金，以开发以伊丽莎白大学医院为中心的精密医学生活实验室。生活实验室旨在整合广泛学科的医学研究，改善患者结局，促进创新，使当地经济受益。该计划包括卓越成像中心(ICE)的临床磁共振技术开发，该中心于2017年开业，将安装在临床环境中的首批7T磁共振扫描仪之一。博士项目将专注于7T MRI在前列腺癌、前列腺癌和前列腺癌的开发和应用与来自MR CoilTech，Siemens Healthcare和NHS的Living Lab合作伙伴合作，MRI是诊断前列腺癌和监测治疗反应的宝贵工具。当前的放射实践依赖于图像的定性视觉评估，但越来越多地使用定量方法来绘制扩散系数和松弛时间图，或分析肿瘤的形状和纹理。目前，前列腺MRI检查是在1.5T或3T的磁场强度下进行的。最近的发展是将7T MRI扫描仪引入临床环境。这些系统提供了更高的信噪比(SNR)[2]，这使得提高空间分辨率并产生更精确的参数估计。这些好处提供了在活体内识别前列腺的组织病理学特征的可能性[3]，以及在根治性前列腺切除术时对T2和T3肿瘤分期的诊断准确性的提高。然而，7T的MRI面临着组织中电磁波长减少的挑战，这导致射频(RF)发射场的不均匀和较差的图像均匀度。这一限制可以通过使用并行发射(PTX)方法[4]来克服，其中多个RF通道与专用脉冲波形一起使用来创建空间均匀的发射场。PTX技术的发展是7T临床MRI的关键要求&这将是Living Lab计划内的学术和行业合作伙伴解决的主题之一。这项工作计划针对许多解剖区域，包括前列腺，这将是拟议的PHD项目的具体焦点。除了开发MRI采集技术之外，Living Lab计划还将提供资金，成立一个医学图像处理小组，将开发用于7T MRI扫描的专用数据处理和可视化工具。这些工具将在PHD项目中使用，以提供可靠的前列腺定量参数图，可以集成到前列腺癌的更广泛的精准医学计划中。PHD项目的目标将是开发7T前列腺的定量MRI，以支持用于前列腺癌临床管理的精准医学方法。这将作为一系列子项目分别实现以下目标：(1)使用用于电磁模拟的商业软件包设计和建造多通道射频发射线圈；(2)线圈技术性能和安全性测试；(3)健康受试者和患者内部PTX脉冲序列和图像处理方案的优化；(4)与标准方法比较的初步临床研究。参照上面列出的子项目，学生将接受以下方面的培训：(1)电气工程和计算机建模的实用技能，射频电子学和电磁学的理论知识；(2)实验设计和数据分析，磁共振成像的安全考虑，医学物理学中的设备测试；(3)磁共振脉冲序列开发，磁共振物理，图像重建处理，科学编程；(4)前列腺MRI的临床研究设计、医学统计、临床方面。

Studentship strategic priority area:Medical Physics Keywords:Prostate, MRI, 7T, RF coilsThis PhD project will be linked to a major new initiative funded by UKRI,who are providing £38m to develop the Precision Medicine Living Lab centred around the Queen Elizabeth University Hospital.The Living Lab aims to integrate medical research across a wide range of disciplines,improving patient outcomes & promoting innovation that will benefit the local economy.The programme includes technology development in clinical MRI at the Imaging Centre of Excellence (ICE), which opened in 2017 to house one of the first 7T MRI scanners installed in a clinical setting.The PhD project will focus on the development & application of 7T MRI for prostate cancer,working in conjunction with Living Lab partners from MR CoilTech,Siemens Healthcare & the NHS.MRI is a valuable tool for the diagnosis of prostate cancer & for monitoring treatment response.Current radiological practice relies on a qualitative visual assessment of images but there is an increasing use of quantitative methods [1] that map diffusion coefficients & relaxation times,or analyse tumour shape & texture.Currently,prostate MRI examinations are performed at a magnetic-field strength of 1.5T or 3T.Recent developments have seen the introduction of 7T MRI scanners into clinical settings.These systems provide a higher signal-to-noise ratio (SNR) [2],which enables an increased spatial resolution & generates more precise parameter estimates.These benefits provide the potential for histopathological features of the prostate to be identified in vivo [3] & for an improved diagnostic accuracy to stage T2 versus T3 tumours at the time of radical prostatectomy.However,MRI at 7T faces the challenge of a reduced electromagnetic wavelength in tissue,which leads to inhomogeneity in the radiofrequency (RF) transmit field and a poor image uniformity.This limitation can be overcome by using parallel-transmit (pTx) methods [4] in which multiple RF channels are used with dedicated pulse waveforms to create a spatially uniform transmit field.The development of pTx technology is a key requirement for clinical MRI at 7T & this will be one of the topics addressed by academic & industry partners within the Living Lab programme.This work is planned for a number of anatomical regions,including the prostate,which will be the specific focus of the proposed PhD project.In addition to the development of MRI acquisition techniques, the Living Lab initiative will also provide funding to start a medical image processing group, which will develop dedicated data-processing and visualisation tools for 7T MRI scans.These tools will be used within the PhD project to provide reliable quantitative parameter maps of the prostate that can be integrated into a wider programme of precision medicine for prostate cancer.The aim of the PhD project will be to develop quantitative MRI of the prostate at 7T to support a precision-medicine approach to the clinical management of prostate cancer.This will be achieved as a series of sub-projects with the following objectives respectively:(1)design & construction of a multi-channel RF transmit coil using a commercial software package for electromagnetic simulation;(2)coil testing for technical performance & safety;(3)optimisation of in-house pTx pulse sequences & image-processing protocols in healthy subjects & patients; &(4) preliminary clinical study to compare with standard methods.With reference to the sub-projects listed above,the student will receive training in the following areas:(1)practical skills in electrical engineering and computer modelling,theoretical knowledge of RF electronics and electromagnetism;(2)experimental design & data analysis,safety considerations in MRI,device testing in medical physics;(3)MRI pulse-sequence development,MRI physics,image reconstruction ?ocessing,scientific programming;(4)clinical-study design,medical statistics,clinical aspects of prostate MRI.