Automatic delineation algorithm of reference region for amyloid imaging based on kinetics
- 51 Downloads
This study aims to develop an algorithm named AutoRef to delineate a reference region for quantitative PET amyloid imaging.
AutoRef sets the reference region automatically using a distinguishing feature in the kinetics of reference region. This is reflected in the shapes of the tissue time activity curve. A statistical shape recognition algorithm of the gaussian mixture model is applied with considering spatial and temporal information on a reference region. We evaluate the BPND with manually set reference region and AutoRef using 86 cases (43 positive cases, 10 equivocal cases, and 33 negative cases) of dynamically scanned 11C-Pittsburgh Compound-B.
From the Bland–Altman plot, the difference between two BPND is 0.099 ± 0.21 as standard deviation, and no significant systematic error is observed between the BPND with AutoRef and with manual definition of a reference region. Although a proportional error is detected, it is smaller than the 95% limits of agreement. Therefore, the proportional error is negligibly small.
AutoRef presents the same performance as the manual definition of the reference region. Further, since AutoRef is more algorithmic than the ordinary manual definition of the reference region, there are few operator-oriented uncertainties in AutoRef. We thus conclude that AutoRef can be applied as an automatic delineating algorithm for the reference region in amyloid imaging.
KeywordsAmyloid imaging Reference region Kinetic analysis
I express my gratitude to Dr. Chisa Hosokawa for her enthusiastic guidance from the beginning. This work is supported by MEXT KAKENHI Grant No. 15H01131 and Kindai University Research Grants: KD201805 from 2015 to 2017 and KD1804 from 2018.
Compliance with ethical standards
Conflict of interest
No potential conflict of interests was disclosed.
- 5.Geoffrey M, David P. Basic definition. Finite mixture models. New York: Wiley; 2000. p. 6–7.Google Scholar
- 6.Kimura Y, Yamada T, Hosokawa C, Okada S, Nagaoka T, Ishii K. Delineation algorithm on reference region for amyloid imaging using a time history of radioactivity: SNMMI 2016 annual meeting. J Nucl Med. 2016;57(2):311.Google Scholar
- 7.Yamada T, Kimura Y, Nagaoka T, Hosokawa C, Murakami T, Ishii K. Algorithm for automated delineation of reference regions using the pattern recognition scheme and kinetics of administered tracer—considering number of clustering—11th Human Amyloid Imaging Conference 2017, pp 36–37.Google Scholar
- 8.Geoffrey M, David P. Starting values for EM algorithm. Finite mixture models. New York: Wiley; 2000. p. 54–57.Google Scholar