Minimally Invasive Image-guided Ablation - MINIMA

目的与目的本课题的目的是将影像学与微创治疗相结合，提高对癌症患者的诊断和治疗水平。磁共振成像（MRI）系统将是用于将磁性粒子移动到体内肿瘤部位并加热粒子的唯一平台，导致周围肿瘤组织中的细胞死亡。使用MRI系统允许在每个步骤中对感兴趣区域进行成像，作为一种新形式的图像引导治疗。磁共振靶向（MRT）技术是利用磁共振成像系统中的梯度线圈来产生磁场梯度，并将粒子移动到体内的靶点，从而实现磁共振成像的目的。一旦到达感兴趣的部位，目的是通过加热颗粒来破坏肿瘤细胞。以前的工作已经证明了MRT的可行性，通过操纵标记有磁性纳米颗粒的细胞。 该项目将通过使用单个钢球而不是纳米颗粒来发展这一想法。增加的颗粒尺寸的缺点是在所获取的图像中观察到的磁化率伪影。钢球内的铁的高磁化率使局部附近的磁场失真，导致T2* 失相增加和信号损失。减小伪影的尺寸将改善钢球的定位，并允许颗粒通过组织的更精确的定位和移动。为了克服这些伪影，已经进行了一些研究，例如猪动脉中的钢球。对于MRes项目，我将研究不同脉冲序列的使用以及更改脉冲序列参数对采集图像的影响。

Aims and ObjectivesThe aim of this project is to improve diagnosis and therapy for patients with cancer, combining imaging with minimally invasive treatment. A Magnetic Resonance Imaging (MRI) system will be the sole platform used for moving a magnetic particle to a tumour site within the body and heating the particle, leading to cell death in the surrounding tumour tissue. Using an MRI system allows the region of interest to be imaged with each step, as a new form of image-guided therapy. The main objective of the MRes project will be to reduce the artefacts observed in the acquired images, which are a result of the high susceptibility of the magnetic particle.BackgroundMagnetic Resonance Targeting (MRT) uses the gradient coils within an MRI system to generate magnetic field gradients and move particles to targeted sites within the body. Once at the site of interest, the intention is to destroy tumour cells via heating of the particles. Previous work has shown the feasibility of MRT, by manipulating cells labelled with magnetic nanoparticles. This project will develop this idea by using a single steel ball, instead of nanoparticles. A disadvantage to the increased particle size is the susceptibility artefacts which are observed in the acquired image. The high susceptibility of the iron within the steel ball distorts the magnetic field in the local vicinity, leading to increased T2* dephasing and loss of signal. Decreasing the size of the artefact will improve the localization of the steel ball and allow more precise location and movement of the particle through the tissue. Some research has been carried out to overcome these artefacts, for a steel ball in a swine artery. For the MRes project I will investigate the use of different pulse sequences and the effect of changing pulse sequence parameters, on the acquired images.