Attenuation correction of PET activation studies in the presenceof task-related motion

Odile A van den Heuvel, Ronald Boellaard, Dick J Veltman, Catalina Mesina, Adriaan A Lammertsma
2003 NeuroImage  
Motion-induced misalignment between transmission and emission scans can result in erroneous estimation of regional tissue activity concentrations. If this motion is of a random nature, mismatch between transmission and emission scans is likely to result in diminished signal-to-noise ratios. In the case of task-related motion, however, corresponding systematic reconstruction artefacts may lead to falsepositive or false-negative results. The purpose of the present study was to investigate whether
more » ... investigate whether implementation of an image registration (IR) method, which allows for motion-corrected attenuation correction, would improve accuracy of H 2 15 O PET activation studies. To evaluate the performance of this method, phantom studies as well as studies in human subjects were performed. Results were compared with three alternative methods: standard attenuation correction without motion correction, calculated attenuation correction, and no attenuation correction. The phantom measurements showed that, for quantitative assessment of regional activity concentrations, the IR method was superior to the other attenuation correction methods. In a single-subject study with intentional task-related motion during a visual stimulation paradigm, false-positive results, obtained with the standard attenuation correction method, disappeared after attenuation correction using the IR method. Finally, a group analysis of 11 patients indicated that an increase in signal-to-noise ratio was obtained with the IR method. Therefore, in our view, the IR method should be considered as a first choice for attenuation correction in PET activation studies.
doi:10.1016/s1053-8119(03)00216-7 pmid:12948706 fatcat:ey2waq46unfoboa7khhjityrbm