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This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Chang, G. Articles by Clark, J. PubMed Articles by Chang, G. Articles by Clark, J.

A low cost prospective amplitude gating device for PET imaging

¹ Imaging Physics, MDACC, Houston, Texas; ² ECE, Rice University, Houston, Texas

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Objectives: To introduce an in-house, low cost, prospective amplitude gating device for commercially available PET/CT scanners.

Methods: A MLT-1132 piezoelectric respiration transducer (AD Instrument, Sydney, Australia) was coupled to a cDAQ-9172 data acquisition device (National Instruments, Austin, TX) to digitize the respiratory signal. A Labview program was designed to inject triggers into the PET List stream whenever the respiration amplitude crossed a user-set threshold. A timer was also programmed to stop the scan when the accumulated scan duration, above the threshold, reached a user-set interval. A phantom containing a static (37 mm) and 2 motion spheres (37 & 22 mm) was imaged on a GE DVCT scanner (SBR=7.4). The two motion spheres were attached to a moving platform (2 cm pp sinusoid waveform, 5 sec cycle) and the transducer monitored the sphere motion. The amplitude threshold and cumulative time were set to 70% and 3 min respectively. This paradigm resulted in 6 min. of scan time. Data was unlisted for 3 & 6 min respectively, and reconstructed using OSEM. Furthermore, the same List data was first filtered by only keeping data when the signal was above the threshold and then reconstructed to generate a gated image (this process although done here retrospectively can be prospectively implemented by manufacturers). The ungated 3 & 6 min. images were compared to the 3 min. gated image using line profiles, contrast, max and mean activity concentration (AC) for all spheres.

Results: The gated image had an average 63, 24 & 24% improvement in contrast, ACmax & ACmean respectively for the two motion spheres when compared to ungated images. The static and gated (37 mm) sphere had similar values.

Conclusions: We have designed a cost effective device for prospective amplitude gating in PET imaging. The cost of the system (HW and SW) is $6182.

This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Chang, G. Articles by Clark, J. PubMed Articles by Chang, G. Articles by Clark, J.