Quantitative accuracy of clinical 99mTc SPECT/CT using ordered-subset expectation maximization with 3-dimensional resolution recovery, attenuation, and scatter correction
Zeintl J, Vija AH, Yahil A, Hornegger J, Kuwert T (2010)
Publication Type: Journal article, Original article
Publication year: 2010
Journal
Original Authors: Zeintl J., Vija A., Yahil A., Hornegger J., Kuwert T.
Publisher: Society of Nuclear Medicine
Book Volume: 51
Pages Range: 921-928
Journal Issue: 6
DOI: 10.2967/jnumed.109.071571
Abstract
We present a calibration method of a clinical SPECT/CT device for quantitative Tc SPECT. We use a commercially available reconstruction package including ordered-subset expectation maximization (OSEM) with depth-dependent 3-dimensional resolution recovery (OSEM-3D), CT-based attenuation correction, and scatter correction. We validated the method in phantom studies and applied it to images from patients injected with Tc-diphosponate. Methods: The following 3 steps were performedtoderive absolute quantitative values from SPECT reconstructed images. In step 1, we used simulations to characterize the SPECT/CT system and derive emission recovery values for various imaging parameter settings. We simulated spheres of varying diameters and focused on the dependencies of activity estimation errors on structure size and position, pixel size, count density, and reconstruction parameters. In step 2, we cross-calibrated our clinical SPECT/CT system with the well counter using a large cylinder phantom. This step provided the mapping from image counts to kBq/mL. And in step 3, correction factors from steps 1 and 2 were applied to reconstructed images. We used a cylinder phantom with variable-sized spheres for verification of the method. For in vivo validation, SPECT/CT datasets from 16 patients undergoing Tc- diphosponate SPECT/CT examinations of the pelvis including the bladder were acquired. The radioactivity concentration in the patients' urine served as the gold standard. Mean quantitative accuracy and SEs were calculated. Results: In the phantom experiments, the mean accuracy in quantifying radioactivity concentration in absolute terms was within 3.6% (SE, 8.0%), with a 95% confidence interval between 219.4% and 112.2%. In the patient studies, the mean accuracy was within 1.1% (SE, 8.4%), with a 95% confidence interval between 215.4% and 117.5%. Conclusion: Current commercially available SPECT/CT technology using OSEM-3D reconstruction, scatter correction, and CT-based attenuation correction allows quantification of Tc radioactivity concentration in absolute terms within 3.6% in phantoms and 1.1% in patients with a focus on the bladder. This opens up the opportunity of SPECT quantitation entering the routine clinical arena. Still, the imprecision caused by unavoidable measurement errors is a dominant factor for absolute quantitation in a clinical setup. COPYRIGHT © 2010 by the Society of Nuclear Medicine, Inc.
Authors with CRIS profile
Joachim Hornegger
Lehrstuhl für Informatik 14 (Bild- und Sprachverarbeitung)
Torsten Kuwert
Lehrstuhl für Klinische Nuklearmedizin
Involved external institutions
Germany (DE)How to cite
APA:
Zeintl, J., Vija, A.H., Yahil, A., Hornegger, J., & Kuwert, T. (2010). Quantitative accuracy of clinical 99mTc SPECT/CT using ordered-subset expectation maximization with 3-dimensional resolution recovery, attenuation, and scatter correction. Journal of Nuclear Medicine, 51(6), 921-928. https://doi.org/10.2967/jnumed.109.071571
MLA:
Zeintl, Johannes, et al. "Quantitative accuracy of clinical 99mTc SPECT/CT using ordered-subset expectation maximization with 3-dimensional resolution recovery, attenuation, and scatter correction." Journal of Nuclear Medicine 51.6 (2010): 921-928.
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