Minimally Invasive Image-guided Ablation - MINIMA

目的与目的本项目旨在将影像与微创治疗相结合，提高癌症患者的诊断和治疗水平。磁共振成像（MRI）系统将是唯一的平台，用于将磁性颗粒移动到体内的肿瘤部位，并加热颗粒，导致周围肿瘤组织的细胞死亡。使用MRI系统可以在每一步中对感兴趣的区域进行成像，作为图像引导治疗的新形式。MRes项目的主要目标将是减少在获得的图像中观察到的伪影，这是磁颗粒高磁化率的结果。背景磁共振靶向（MRT）利用MRI系统内的梯度线圈产生磁场梯度，并将粒子移动到体内的目标部位。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。先前的工作已经证明了MRT的可行性，通过操纵带有磁性纳米颗粒的细胞。这个项目将通过使用一个钢球而不是纳米粒子来实现这个想法。增大颗粒尺寸的缺点是在获得的图像中观察到的敏感性伪影。钢球内铁的高磁化率使局部附近的磁场发生畸变，导致T2*失相和信号损失增大。减小人工制品的尺寸将改善钢球的定位，并允许更精确的定位和颗粒通过组织的运动。已经进行了一些研究来克服这些人工制品，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改变脉冲序列参数对所获取图像的影响。

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.