Respiratory motion handling is mandatory to accomplish the high-resolution PET destiny

Excerpt

Positron emission tomography (PET) is an interesting metabolic imaging modality. Its strength relies mostly on its ability to quantify the measured metabolic signal. Recent developments with PET have enabled to reach the 2- to 5-mm full-width-at-half-maximum (FWHM) spatial resolution. With such an improvement, small amounts of motion during acquisition deteriorate the effective spatial resolution [1]. In order to take advantage of this wonderful recent amelioration in PET spatial resolution, it becomes critical to account for any intervening motion particularly respiratory motion, in order to minimize its effect on effective resolution. In the following, we will limit our editorial to respiratory motion, our subject of interest, and will not address other not specifically less important causes of motion, i.e., patient motion, cardiac contraction related motion, displacement of internal organs, and other physiologic organ motion (bowel, gallbladder ...). In the first part of the editorial, we will address the rational justifying respiratory motion consideration with PET. In the second part, we will address issues related to the combined use of emission/transmission scans and the problems of respiratory motion consideration. In the third part, we will address the desirable ultimate goal of respiratory motion handling and review actual proposed methods. …