Affiliations: [a] Biomedical Engineering Department, Rensselaer Polytechnic Institute, Troy, NY, USA
| [b] Chemistry Department, University of Massachusetts Lowell, Lowell, MA, USA
| [c]
MARS Bioimaging Ltd., Christchurch, New Zealand
Correspondence:
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Corresponding authors: Manos Gkikas, Chemistry Department, University of Massachusetts Lowell, Lowell, MA, USA. Tel.: +1 978 934 3245; E-mail: Manos_Gkikas@uml.edu and Ge Wang, Biomedical Engineering Department, Rensselaer Polytechnic Institute, Troy, NY, USA. Tel.: +1 518 276 3726; E-mail: wangg6@rpi.edu.
Abstract: BACKGROUND:X-ray CT/micro-CT methods with photon-counting detectors (PCDs) and high Z materials are a hot research topic. One method using PCDs allows for spectral imaging in 5 energy windows while conventional X-ray detectors only collect energy-integrating data. OBJECTIVE:To demonstrate the enhanced separation of contrast materials by using PCDs, multivariate analysis, and linear discriminant methods. METHODS:Phantoms containing iodine and aqueous nanomaterials were scanned on a MARS spectral micro-CT. Image volumes were segmented into separate material-specific populations. Contrast comparisons were made by calculating T2 test statistics in the univariate, pseudo-conventional and multivariate, spectral CT data sets. Separability after Fisher discriminant analysis (FDA) was also assessed. RESULTS:The T2 values calculated for material comparisons increased as a result of the spectral expansion. The majority of the tested contrast agents showed increased T2 values by a factor of ∼2 -3. The total significant T2 statistics in the pure and mixed lanthanide image sets increased in the spectral data set. CONCLUSION:This work consolidates the groundwork for photon-counting-based material decomposition with micro-CT, facilitating future development of novel nanomaterials and their preclinical applications.
