Effect of respiratory gating on quantifying PET images of XXXX .

@entity1 @entity2 @entity419
We have developed a new technique to gate lung @entity419 PET images in synchronization with the respiratory motion to reduce smearing due to breathing and improve quantitation of @entity419 uptake in lung lesions. METHODS: A camera-based respiratory gating system, the real-time position management (RPM), is used to monitor the respiratory cycle. The RPM provides a trigger to the PET scanner to initiate the gating cycle. Each respiratory cycle is divided into discrete bins triggered at a defined amplitude or phase within the @entity1 's breathing motion, into which PET data are acquired. The acquired data within the time bins correspond to different lesion positions within the breathing cycle. The study includes 5 @entity1 with @entity2 . RESULTS: Measurements of the lesions' volumes in the gated mode showed a reduction of up to 34% compared with that of the nongated measurement. This reduction in the lesion volume has been accompanied by an increase in the intensity in the @entity419 signal per voxel. This finding has resulted in an improvement in measurement of the maximum standardized uptake value (SUV(max)), which increased in 1 @entity1 by as much as 159%. The total lesion glycolysis, defined as the product of the SUV(max) and the lesion volume, was also measured in gated and nongated modes and showed a consistency between the 2 measurements. CONCLUSION: We have shown that image smearing can be reduced by gating @entity419 PET images in synchronization with the respiratory motion. This technique allows a more accurate definition of the lesion volume and improves the quantitation specific activity of the tracer (in this case, @entity419 ), which are distorted because of the breathing motion.
