Leslie W D, Dupont J O, McDonald D, Peterdy A E
Department of Nuclear Medicine, St. Boniface General Hospital, University of Manitoba, Winnipeg, Canada.
J Nucl Med. 1997 May;38(5):785-90.
Patient motion remains a significant source of unsatisfactory cardiac SPECT examinations. The extent to which image recovery can be achieved with correction algorithms is unknown.
Nine subjects who had completed motion-free redistribution 201Tlcardiac SPECT subsequently underwent simultaneous dual-isotope (201Tl/99mTc) SPECT with a 99mTc cutaneous point source, while the imaging table was subjected to predefined nonreturning y-translation movements. Cardiac reconstructions, marker reconstructions and marker-compressed dynamic images were generated from the raw data after applying the following correction methods: diverging squares, cross-correlation of the cardiac data and cross-correlation of the marker.
Marker cross-correlation performed significantly better than all other methods with good-excellent results in all evaluations. This compared with good-excellent results in none of 27 for the raw data, in 13 of 27 for cardiac cross-correlation and in 7 of 27 for diverging squares (p < 10(-5)). The superiority of the marker-based method was confirmed on analysis of bullseye difference maps and quantitation of residual motion in the point-source data.
Motion artifacts can accurately be detected and corrected using cross-correlation of an external point-source. Furthermore, this technique provides useful independent information on the degree of image recovery.
患者运动仍是心脏单光子发射计算机断层显像（SPECT）检查结果不理想的一个重要原因。校正算法能够实现图像恢复的程度尚不清楚。
9名已完成静息再分布201铊心脏SPECT检查的受试者随后接受了同时双同位素（201铊/99锝）SPECT检查，使用99锝皮肤点源，同时成像台进行预先定义的非返回y轴平移运动。在应用以下校正方法后，从原始数据生成心脏重建图像、标记物重建图像和标记物压缩动态图像：发散方块法、心脏数据互相关法和标记物互相关法。
标记物互相关法在所有评估中表现均显著优于所有其他方法，结果良好至优秀。相比之下，原始数据在27次评估中无一结果良好至优秀，心脏互相关法在27次中有13次，发散方块法在27次中有7次（p < 10(-5)）。基于标记物的方法的优越性在分析靶心差异图和定量点源数据中的残余运动时得到证实。
使用外部点源互相关法能够准确检测和校正运动伪影。此外，该技术可提供关于图像恢复程度的有用独立信息。
