Effects of attenuation map accuracy on attenuation-corrected micro-SPECT images

Effects of attenuation map accuracy on attenuation-corrected micro-SPECT images

Wu, C.
Gratama van Andel, H.A.
Laverman, P.
Boerman, O.C.
Beekman, F.J.

Applied Sciences

RST/Radiation, Science and Technology

2013-01-31

Background In single-photon emission computed tomography (SPECT), attenuation of photon flux in tissue affects quantitative accuracy of reconstructed images. Attenuation maps derived from X-ray computed tomography (CT) can be employed for attenuation correction. The attenuation coefficients as well as registration accuracy between SPECT and CT can be influenced by several factors. Here we investigate how such inaccuracies influence micro-SPECT quantification. Methods Effects of (1) misalignments between micro-SPECT and micro-CT through shifts and rotation, (2) globally altered attenuation coefficients and (3) combinations of these were evaluated. Tests were performed with a NEMA NU 4–2008 phantom and with rat cadavers containing sources with known activity. Results Changes in measured activities within volumes of interest in phantom images ranged from <1.5% (125I) and <0.6% (201Tl, 99mTc and 111In) for 1-mm shifts to <4.5% (125I) and <1.7% (201Tl, 99mTc and 111In) with large misregistration (3?mm). Changes induced by 15° rotation were smaller than those by 3-mm shifts. By significantly altering attenuation coefficients (±10%), activity changes of <5.2% for 125I and <2.7% for 201Tl, 99mTc and 111In were induced. Similar trends were seen in rat studies. Conclusions While getting sufficient accuracy of attenuation maps in clinical imaging is highly challenging, our results indicate that micro-SPECT quantification is quite robust to various imperfections of attenuation maps

molecular imaging
SPECT
CT
small animal
misregistration
attenuation correction
quantification

http://resolver.tudelft.nl/uuid:6b0a3ed8-0d56-4c52-9609-2dd345677194

https://doi.org/10.1186/2191-219X-3-7

BioMed Central

2191-219X

http://www.ejnmmires.com/content/3/1/7

EJNMMI Research, 3 (7), 2013

Institutional Repository

journal article

© 2013 The Author(s)
Licensee Springer
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.