title: Development of a Germanium Small-Animal SPECT System.
abstract: Advances in fabrication techniques, electronics, and mechanical cooling systems have given rise to germanium detectors suitable for biomedical imaging. We are developing a small-animal SPECT system that uses a double-sided Ge strip detector. The detector's excellent energy resolution may help to reduce scatter and simplify processing of multi-isotope imaging, while its ability to measure depth of interaction has the potential to mitigate parallax error in pinhole imaging. The detector's energy resolution is <1% FWHM at 140 keV and its spatial resolution is approximately 1.5 mm FWHM. The prototype system described has a single-pinhole collimator with a 1-mm diameter and a 70-degree opening angle with a focal length variable between 4.5 and 9 cm. Phantom images from the gantry-mounted system are presented, including the NEMA NU-2008 phantom and a hot-rod phantom. Additionally, the benefit of energy resolution is demonstrated by imaging a dual-isotope phantom with99mTc and123I without cross-talk correction.
authors.affiliation: Vanderbilt University Institute of Imaging Science and the Department of Radiology and Radiological Sciences, Nashville, TN 37232 USA and is now with the University of Pennsylvania Department of Radiology, Philadelphia PA 19104 USA.
authors.forename: Lindsay C
authors.initials: LC
authors.lastname: Johnson
authors.affiliation: Vanderbilt University Institute of Imaging Science and the Department of Physics, Nashville, TN 37232 USA.
authors.forename: Oleg
authors.initials: O
authors.lastname: Ovchinnikov
authors.affiliation: Vanderbilt University Institute of Imaging Science and the Department of Radiology and Radiological Sciences, Nashville, TN 37232 USA.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Shokouhi
authors.affiliation: Vanderbilt University Institute of Imaging Science, the Department of Physics and Astronomy, and the Department of Radiology and Radiological Sciences Nashville, TN 37232 USA.
authors.forename: Todd E
authors.initials: TE
authors.lastname: Peterson
keywords: Energy resolution; SPECT; germanium detector; instrumentation; nuclear imaging; semiconductor detectors; small-animal imaging