PT  - JOURNAL ARTICLE
AU  - Guoping Chang
AU  - Tinsu Pan
AU  - Tingting Chang
AU  - Eric Rohren
AU  - John Clark
AU  - Osama Mawlawi
TI  - Automation of respiratory amplitude gating in whole-body PET/CT imaging
DP  - 2009 May 01
TA  - Journal of Nuclear Medicine
PG  - 56--56
VI  - 50
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/50/supplement_2/56.short
4100  - http://jnm.snmjournals.org/content/50/supplement_2/56.full
SO  - J Nucl Med2009 May 01; 50
AB  - 56 Objectives To automate respiratory amplitude gating (RAG) in whole body (WB) PET/CT imaging while matching the respiratory amplitude captured during CT with a corresponding amplitude gated PET scan. Methods A PET-first protocol is used whereby a WB PET scan is first acquired and reconstructed to determine the location of a lesion. A WB CT scan is then acquired while the X-ray ON signal & the patient's respiratory motion are recorded by a cDAQ-9172 device (NI, Austin, TX) & a respiratory gating device (Anzai Med. Co., Japan) respectively. The two devices are synchronized by a trigger from the Anzai device during CT scan. The tumor motion amplitude at the time of the CT scan is determined from the X-ray ON signal, respiration signal, & tumor location. The Anzai device is configured to output a gating signal whenever the motion falls within a range determined by this amplitude. A 3-min PET scan is then acquired over the tumor location and a Labview® program is designed to inject a trigger into the PET List stream whenever the rising/falling edge of the gating signal is detected. The List data within the gate is then extracted and reconstructed to generate an amplitude-gated image . This RAG technique was tested on 10 patients with 16 lung/liver tumors. The resultant gated & ungated images were compared using visual inspection (VI), line profiles (LP), and max & mean SUV using a 40% threshold of the max SUV. Results Gated images showed better contrast using VI & LP, and had an average 22 & 24% improvement in mean & max SUV versus ungated images. Conclusions RAG can be automated on PET/CT scanners without requesting patients to hold breath or increase X-ray exposure.