Kennedy John A, Israel Ora, Frenkel Alex, Bar-Shalom Rachel, Azhari Haim
Faculty of Biomedical Engineering, Technion, Israel Institute of Technology, Haifa.
IEEE Trans Med Imaging. 2006 Feb;25(2):137-47. doi: 10.1109/TMI.2005.861705.
This paper demonstrates a super-resolution method for improving the resolution in clinical positron emission tomography (PET) scanners. Super-resolution images were obtained by combining four data sets with spatial shifts between consecutive acquisitions and applying an iterative algorithm. Super-resolution attenuation corrected PET scans of a phantom were obtained using the two-dimensional and three-dimensional (3-D) acquisition modes of a clinical PET/computed tomography (CT) scanner (Discovery LS, GEMS). In a patient study, following a standard 18F-FDG PET/CT scan, a super-resolution scan around one small lesion was performed using axial shifts without increasing the patient radiation exposure. In the phantom study, smaller features (3 mm) could be resolved axially with the super-resolution method than without (6 mm). The super-resolution images had better resolution than the original images and provided higher contrast ratios in coronal images and in 3-D acquisition transaxial images. The coronal super-resolution images had superior resolution and contrast ratios compared to images reconstructed by merely interleaving the data to the proper axial location. In the patient study, super-resolution reconstructions displayed a more localized 18F-FDG uptake. A new approach for improving the resolution of PET images using a super-resolution method has been developed and experimentally confirmed, employing a clinical scanner. The improvement in axial resolution requires no changes in hardware.
本文展示了一种用于提高临床正电子发射断层扫描（PET）扫描仪分辨率的超分辨率方法。通过将四个数据集与连续采集之间的空间偏移相结合，并应用迭代算法来获得超分辨率图像。使用临床PET/计算机断层扫描（CT）扫描仪（Discovery LS，GEMS）的二维和三维（3-D）采集模式，获得了体模的超分辨率衰减校正PET扫描图像。在一项患者研究中，在进行标准的18F-FDG PET/CT扫描后，在不增加患者辐射暴露的情况下，围绕一个小病灶进行了轴向偏移的超分辨率扫描。在体模研究中，与未使用超分辨率方法时相比（6毫米），使用超分辨率方法在轴向可以分辨出更小的特征（3毫米）。超分辨率图像比原始图像具有更好的分辨率，并且在冠状图像和3-D采集的横断面图像中提供了更高的对比度。与仅仅将数据交错到适当轴向位置重建的图像相比，冠状超分辨率图像具有更高的分辨率和对比度。在患者研究中，超分辨率重建显示出更局部化 的18F-FDG摄取。已经开发并通过实验证实了一种使用超分辨率方法提高PET图像分辨率的新方法，该方法采用了临床扫描仪。轴向分辨率的提高无需硬件更改。
