Breen Michael S, Lazebnik Roee S, Nour Sherif G, Lewin Jonathan S, Wilson David L
Department of Biomedical Engineering, University Hospitals of Cleveland & Case Western Reserve University, Cleveland, Ohio 44106, USA.
Comput Aided Surg. 2004;9(5):185-91. doi: 10.3109/10929080500130330.
Solid tumors are being treated using radiofrequency (RF) ablation under interventional magnetic resonance imaging (MRI) guidance. We are investigating the ability of MRI to monitor ablation treatments by comparing MR images of thermal lesions to histologically assayed tissue damage.
An open MRI system was used to guide an ablation electrode into five rabbit thigh muscles and acquire post-ablation MR image volumes. We developed a methodology using a 3D computer registration to make spatial correlations. After MR and histology images were registered with an accuracy of 1.32+/-0.39 mm (mean+/-SD), a boundary of necrosis identified in the histology was compared with the outer boundary of the hyperintense region in MR images.
For 14 T2-weighted MR images, the absolute distance between boundaries was 0.96+/-0.34 mm (mean+/-SD). Since the small discrepancy between boundaries is comparable to our registration accuracy, the boundaries may match exactly. Similar correlations to histology were obtained with a deformable model segmentation method.
This is good evidence that MR thermal lesion images can be used during RF ablation treatments to accurately localize the zone of necrosis at the lesion margin.
在介入磁共振成像（MRI）引导下，使用射频（RF）消融术治疗实体瘤。我们正在通过比较热损伤的磁共振图像与经组织学分析的组织损伤，来研究MRI监测消融治疗的能力。
使用开放式MRI系统将消融电极引导至五只兔子的大腿肌肉中，并获取消融后的磁共振图像容积。我们开发了一种使用三维计算机配准来进行空间关联的方法。在磁共振图像和组织学图像以1.32±0.39毫米（平均值±标准差）的精度配准后，将组织学中确定的坏死边界与磁共振图像中高信号区域的外边界进行比较。
对于14幅T2加权磁共振图像，边界之间的绝对距离为0.96±0.34毫米（平均值±标准差）。由于边界之间的微小差异与我们的配准精度相当，边界可能完全匹配。使用可变形模型分割方法也获得了与组织学相似的相关性。
这充分证明了在射频消融治疗期间，磁共振热损伤图像可用于准确确定病变边缘的坏死区域。
