Dual source hybrid spectral micro-CT using an energy-integrating and a photon-counting detector.
Abstract
Preclinical micro-CT provides a hotbed in which to develop new imaging technologies,
including spectral CT using photon counting detector (PCD) technology. Spectral imaging
using PCDs promises to expand x-ray CT as a functional imaging modality, capable of
molecular imaging, while maintaining CT's role as a powerful anatomical imaging modality.
However, the utility of PCDs suffers due to distorted spectral measurements, affecting
the accuracy of material decomposition. We attempt to improve material decomposition
accuracy using our novel hybrid dual-source micro-CT system which combines a PCD and
an energy integrating detector. Comparisons are made between PCD-only and hybrid CT
results, both reconstructed with our iterative, multi-channel algorithm based on the
split Bregman method and regularized with rank-sparse kernel regression. Multi-material
decomposition is performed post-reconstruction for separation of iodine (I), gold
(Au), gadolinium (Gd), and calcium (Ca). System performance is evaluated first in
simulations, then in micro-CT phantoms, and finally in an in vivo experiment with
a genetically modified p53fl/fl mouse cancer model with Au, Gd, and I nanoparticle (NP)-based contrasts agents. Our
results show that the PCD-only and hybrid CT reconstructions offered very similar
spatial resolution at 10% MTF (PCD: 3.50 lp mm-1; hybrid: 3.47 lp mm-1) and noise characteristics given by the noise power spectrum. For material decomposition
we note successful separation of the four basis materials. We found that hybrid reconstruction
reduces RMSE by an average of 37% across all material maps when compared to PCD-only
of similar dose but does not provide much difference in terms of concentration accuracy.
The in vivo results show separation of targeted Au and accumulated Gd NPs in the tumor
from intravascular iodine NPs and bone. Hybrid spectral micro-CT can benefit nanotechnology
and cancer research by providing quantitative imaging to test and optimize various
NPs for diagnostic and therapeutic applications.
Type
Journal articleSubject
AnimalsHumans
Mice
Sarcoma
Sarcoma, Experimental
Iodine
Gadolinium
Contrast Media
Phantoms, Imaging
Algorithms
Photons
Image Processing, Computer-Assisted
X-Ray Microtomography
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https://hdl.handle.net/10161/24253Published Version (Please cite this version)
10.1088/1361-6560/aba8b2Publication Info
Holbrook, MD; Clark, DP; & Badea, CT (2020). Dual source hybrid spectral micro-CT using an energy-integrating and a photon-counting
detector. Physics in medicine and biology, 65(20). pp. 205012. 10.1088/1361-6560/aba8b2. Retrieved from https://hdl.handle.net/10161/24253.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Cristian Tudorel Badea
Professor in Radiology
Our lab's research focus lies primarily in developing novel quantitative imaging systems,
reconstruction algorithms and analysis methods. My major expertise is in preclinical
CT.
Currently, we are particularly interested in developing novel strategies for spectral
CT imaging using nanoparticle-based contrast agents for theranostics (i.e. therapy
and diagnostics).
We are also engaged in developin
Darin Clark
Assistant Professor in Radiology
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