Simultaneous Tc-99m/Tl-201 imaging using energy-based estimation of the spatial distributions of contaminant photons

Journal Article · Tue Aug 01 04:00:00 EDT 1995 · IEEE Transactions on Nuclear Science

DOI:https://doi.org/10.1109/23.467879· OSTI ID:148068

Moore, S C; Tow, D E ^[1]; English, R J; Syravanh, C ^[1]; Zimmerman, R E; Chan, K H; Kijewski, M F ^[2]

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1. V.A. Medical Center, W. Roxbury, MA (United States). Nuclear Medicine Service
2. Harvard Medical School, Boston, MA (United States)

The advantages of simultaneous acquisition of TC-99m and Tl-201 myocardial perfusion SPECT images can be fully realized only if the effects of the Tc-99m agent can be accurately removed from the Tl-201 image. The authors and others have previously reported simultaneous dual-isotope techniques for cardiac studies which make use of a third energy-window to estimate the Tc-99m scatter to be subtracted from the Tl-201 window. The authors have recently demonstrated, however, using a Monte Carlo program which simulates all details of the photon transport, that lead x-rays produced in the collimator may also contribute significantly to contamination in the Tl-201 window. The spatial distribution of the Tc-99m scattered photons differs from that of the lead x-rays. Therefore, the authors modified their correction technique so that, at each projection angle, the contaminant image to be subtracted from the image in the Tl-201 window was estimated as a linear combination of a scatter-window (90--110 keV) image, blurred by a 2D Gaussian filter, and the Tc-99m photopeak image, blurred by a different Gaussian filter. For simulated data which included `liver` activity and non-uniform `lung` attenuation, the improved dual-window subtraction technique provided a more accurate estimate of the true Tl-201 image, with less image noise, than did the single-window correction.

• OSTI ID: 148068
• Report Number(s): CONF-941061--
• Journal Information: IEEE Transactions on Nuclear Science, Journal Name: IEEE Transactions on Nuclear Science Journal Issue: 4Pt1 Vol. 42; ISSN 0018-9499; ISSN IETNAE
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
ACCURACY
DATA ACQUISITION
IMAGE PROCESSING
ISOMERIC NUCLEI
MYOCARDIUM
PERFUSED TISSUES
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
TECHNETIUM 99
THALLIUM 201