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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 Conwell, R. Articles by Maddahi, J. PubMed Articles by Conwell, R. Articles by Maddahi, J.

A novel cardiac SPECT system with X-ray-based attenuation correction using the same solid state detectors for both emission and transmission scans

¹ Digirad Corporation, Poway, California; ² UCLA -- David Geffen School of Medicine, Los Angeles, California

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Objectives: Radio-isotopic-source-based and CT-based approaches are the two standard approaches for performing attenuation correction (AC) in cardiac SPECT. Drawbacks of the first approach are (1) the transmission scans significantly increase the study time due to the limited strength of the transmission sources and/or the low count rate capability of conventional Anger detectors and (2) the obtained attenuation maps are noisy. Drawbacks of the second approach include (1) the need for a completely different detector system and (2) high patient dose from CT scans. In this work, we employ a low-dose x-ray transmission source for transmission scans using high-count-rate-capable solid-state detectors that are also used for emission scans. This configuration enables high quality attenuation maps to be obtained with minimal increase in total study time and with insignificant added dose to the patient.

Methods: An upright solid-state camera with fan-beam collimators was used for both emission and transmission scans of an anthropomorphic phantom. For transmission scans, a collimated line source was formed using an x-ray generator, and positioned at the focal line of the collimators. The camera could handle count rates greater than 12 Mcps which allowed transmission scans to be finished in 30 seconds.

Results: Phantom studies showed high quality attenuation maps and improved uniformity in the image of the cardiac insert with AC (87±4), compared to the image without AC(78±6). The transmission dose was less than an equivalent injected dose of 5 uCi of Tc-99m.

Conclusions: We developed a new X-ray-Based transmission approach for AC in cardiac SPECT. High-quality transmission scans can be completed within one minute and with negligible patient dose.

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 Conwell, R. Articles by Maddahi, J. PubMed Articles by Conwell, R. Articles by Maddahi, J.