Physics Department, Clatterbridge Centre for Oncology NHS Trust, Wirral, Merseyside, UK.
Clin Oncol (R Coll Radiol). 2010 Oct;22(8):688-97. doi: 10.1016/j.clon.2010.06.016. Epub 2010 Jul 31.
Magnetic resonance imaging (MRI) is being increasingly used in radiotherapy treatment planning (RTP). MRI has the potential to provide improved localisation of target volumes, leading to better tumour control rates and reduced normal tissue complications, due to capabilities including excellent soft-tissue discrimination and the ability to provide scans in which the image contrast is weighted according to different tissue properties. When computed tomography (CT)-MRI image registration is deployed, MR's advantages are combined with CT's geometrical security and its ability to provide electron density information. The quality of CT-MRI image registration can be favourably influenced by aspects of scan acquisition, including patient positioning/immobilisation and scan protocols. Appropriate protocols can ameliorate the possible presence of MR spatial distortions and other artefacts, but quality assurance of scanning remains essential. Here, the methods and quality assurance of CT-MR image registration are discussed. Developments in MRI scanner technology are progressively offering advantages for RTP, in terms of the possibility of better matching of patient positioning versus CT in a greater range of anatomical regions, while allowing thinner slices for better image quality in reformatted orthogonal planes.
磁共振成像（MRI）在放射治疗计划（RTP）中越来越多地被使用。由于包括出色的软组织分辨力和根据不同组织特性对图像对比度进行加权的能力等功能，MRI 有可能提供更准确的靶区定位，从而提高肿瘤控制率并减少正常组织并发症。当使用计算机断层扫描（CT）-MRI 图像配准时，MRI 的优势与 CT 的几何安全性及其提供电子密度信息的能力相结合。扫描采集的各个方面，包括患者定位/固定和扫描方案，都可以对 CT-MRI 图像配准的质量产生有利影响。适当的方案可以减轻 MRI 空间变形和其他伪影的可能存在，但扫描的质量保证仍然至关重要。在这里，讨论了 CT-MR 图像配准的方法和质量保证。MRI 扫描仪技术的发展在 RTP 方面逐渐具有优势，例如在更大的解剖区域内更好地匹配患者体位与 CT，同时允许更薄的切片以在重新格式化的正交平面上获得更好的图像质量。
