PT  - JOURNAL ARTICLE
AU  - Xiao Jin
AU  - Tim Mulnix
AU  - Christine Sandiego
AU  - Mu Chen
AU  - Richard Carson
TI  - List-mode reconstruction for the FOCUS-220 with motion correction: Application to awake nonhuman primate imaging
DP  - 2011 May 01
TA  - Journal of Nuclear Medicine
PG  - 151--151
VI  - 52
IP  - supplement 1
4099  - http://jnm.snmjournals.org/content/52/supplement_1/151.short
4100  - http://jnm.snmjournals.org/content/52/supplement_1/151.full
SO  - J Nucl Med2011 May 01; 52
AB  - 151 Objectives Motion correction for PET brain imaging of awake non-human primates (NHP) is necessary if head fixation is not used. Previous studies [1] have used the multi-acquisition frame (MAF) method, in which the list-mode file was divided into sub-frames for reconstruction, based on an intra-frame motion threshold and a minimal frame duration threshold. While this method corrects for most of the motion, intra-frame blurring is present and scan data are discarded. In this study, we implemented a list-mode reconstruction algorithm for the FOCUS-220 with motion correction, based on MOLAR [2]. Methods Motion data were acquired with the Vicra system with a novel technique for time synchronization between list-mode and motion data. Using the motion data, the coordinates of each detected line of response was transformed to the reference orientation. For attenuation correction, a transmission image from an anesthetized scan of the same subject was resliced to the reference orientation of this study. Single scatter simulation is used for scatter correction. Randoms are estimated from the block singles rate. This method was validated with a line source scan and a liquid phantom scan. We performed five awake NHP studies, each reconstructed with the list-mode method, the MAF method and without motion correction. Results For motion of 9.6mm, uncorrected images show substantial motion-induced degradation (Fig 1A). List-mode reconstruction with motion correction (1C) noticeably improved image resolution over the MAF method (1B), and produced comparable image resolution to an anesthetized study (1D). List-mode reconstruction used all events, improving the statistical quality over MAF which keeps half of the counts. Conclusions List-mode reconstruction with motion correction reliably corrects for head motion, producing better image resolution than the MAF method in awake NHP studies. Research Support Grant number R01NS058360 from the National Institute of Neurological Disorders and Strok