First application of liquid-metal-jet sources for small-animal imaging: High-resolution CT and phase-contrast tumor demarcation
2013 (English)In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 40, no 2, 021909- p.Article in journal (Refereed) Published
Purpose: Small-animal studies require images with high spatial resolution and high contrast due to the small scale of the structures. X-ray imaging systems for small animals are often limited by the microfocus source. Here, the authors investigate the applicability of liquid-metal-jet x-ray sources for such high-resolution small-animal imaging, both in tomography based on absorption and in soft-tissue tumor imaging based on in-line phase contrast. Methods: The experimental arrangement consists of a liquid-metal-jet x-ray source, the small-animal object on a rotating stage, and an imaging detector. The source-to-object and object-to-detector distances are adjusted for the preferred contrast mechanism. Two different liquid-metal-jet sources are used, one circulating a Ga/In/Sn alloy and the other an In/Ga alloy for higher penetration through thick tissue. Both sources are operated at 40-50 W electron-beam power with similar to 7 mu m x-ray spots, providing high spatial resolution in absorption imaging and high spatial coherence for the phase-contrast imaging. Results: High-resolution absorption imaging is demonstrated on mice with CT, showing 50 mu m bone details in the reconstructed slices. High-resolution phase-contrast soft-tissue imaging shows clear demarcation of mm-sized tumors at much lower dose than is required in absorption. Conclusions: This is the first application of liquid-metal-jet x-ray sources for whole-body small-animal x-ray imaging. In absorption, the method allows high-resolution tomographic skeletal imaging with potential for significantly shorter exposure times due to the power scalability of liquid-metal-jet sources. In phase contrast, the authors use a simple in-line arrangement to show distinct tumor demarcation of few-mm-sized tumors. This is, to their knowledge, the first small-animal tumor visualization with a laboratory phase-contrast system.
Place, publisher, year, edition, pages
2013. Vol. 40, no 2, 021909- p.
small-animal imaging, liquid-metal-jet, x-ray, CT, tumor demarcation, mouse
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-119468DOI: 10.1118/1.4788661ISI: 000314727700038PubMedID: 23387757ScopusID: 2-s2.0-84873576570OAI: oai:DiVA.org:kth-119468DiVA: diva2:611836
FunderSwedish Research CouncilVinnova
QC 201303192013-03-192013-03-142015-03-31Bibliographically approved