I just try to put together some lecture notes about possible artifacts that can occur during micro-CT data acquisition and somehow I haven't yet come across an in-depth review covering multiple types of micro-CT artifact (ring, misalignment, partial-volume, noise, beam hardening etc.). Do you have any recommendation for a paper/book chapter/online-lecture?
Is this micro-CT single/multi slice scanner or a cone-beam scanner?
I would not consider partial volume effect an artifact.
You could add 'out-of-field', metal, scatter, detector saturation, ghosting and low photon count artifacts.
Are the artifacts of micro-CT different from 'macro' CT? I mean, the artifacts you mention sound very familiar to me...
I assume, some of them will be the same as in clinical CTs - but as the sample rotates rather then the source/detector (in a cone-beam arrangement), there might be some differences in the manifestation of the artefacts. Would you know of any review articles for clinical CTs?
There are some papers on clinical CT artifacts, but don't know if any of them is in-depth enough for you:
http://pubs.rsna.org/doi/full/10.1148/rg.246045065
http://www.edboas.com/science/CT/0012.pdf
http://www.appliedradiology.com/Issues/2003/08/Articles/Common-artifacts-in-computerized-tomography--A-review.aspx
There is an extensive chapter on CT artifacts in this book by Thorsten M. Buzug:
"Computed Tomography: From Photon Statistics to Modern Cone-Beam CT"
Unfortunately, it costs some money:
http://www.amazon.com/Computed-Tomography-Photon-Statistics-Cone-Beam/dp/3642072577
Sorry, I don't know about a review article, but I guess a lot can be found on the web.
Thanks a lot for the answers!
Witold, I did had the Barrett & Keat 2004 and Boas&Fleischmann paper already.. Will have a look in our library's copy of Buzug's book as well. but thought there might be a more specific one for micro-CT imaging.
The problems for Micro-CT are a bit different from what we find clinically. Most volumes are acquires in one scan not multi-slice so those artifacts are not present. Low photon statistics, sample movement, and beam hardening is present due to the small flux and relatively low energies. Below are 4 papers that are useful in describing and mitigating some of these artifacts.
1. Kyriakou, Y., Prell, D. & Kalender, W. A. Ring artifact correction for high-resolution micro CT. Phys Med Biol 54, N385–91 (2009).
2. Meganck, J. A., Kozloff, K. M., Thornton, M. M., Broski, S. M. & Goldstein, S. A. Beam hardening artifacts in micro-computed tomography scanning can be reduced by X-ray beam filtration and the resulting images can be used to accurately measure BMD. Bone 45, 1104–1116 (2009).
3. Prell, D., Kyriakou, Y. & Kalender, W. A. Comparison of ring artifact correction methods for flat-detector CT. Phys Med Biol 54, 3881–3895 (2009).
4. Hupfer, M., Nowak, T., Brauweiler, R., Eisa, F. & Kalender, W. A. Spectral optimization for micro-CT. Med Phys 39, 3229 (2012).
@ H. Morris : How do you mean 'are acquired in one scan'? A scan takes time, whether cone beam or a single/multi slice CT. True that some artifacts may present themselves differently, e.g. breathing artifacts (blurring and distortion respectively).
Beam hardening is not caused by low energy, but because the X-ray source is not monochromatic (different attenuation coefficients for different energies).
By the way Michael, in our hospital we have a stationary sample (a mouse) and a rotating source/detector (micro cone-beam CT).
As far as I know, artifacts are the same as encountered in macro cone-beam, and many artifacts are also shared with helical CT.
A more concise review is Boas and Fleishmann. 1. Boas, F. E. & Fleischmann, D. CT artifacts: causes and reduction techniques. Imaging Med 4, 229–240 (2012).
Also available directly from Ed Boas at the link below.
http://www.edboas.com/science/CT/0012.pdf
@Lambert Zijp - I was referring to cone-beam scan with one volume of acquisition. You are correct that the artifacts generally are the same as clinical scans. Specimen scanners do have the problem of moving sample motion or in very high resolution cases thermal shifts due to temperature changes in the sample over the duration of the scan. I didn't mean to muddle the issue. Thanks for pointing that out.
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