Our research is driven by collaborations with a number of organizations including the University of Canterbury, University of Otago, University of Auckland, and Lincoln University. International collaborations include CERN, Lausanne University, University of Maryland, University of Pennsylvania, Oregon Health and Science University, and Rensselaer Polytechnic Institute. Below are examples of our research, for a full list of scientific publications, click here. If you would like to request sample datasets please email firstname.lastname@example.org.
Detection of arthroplasty implant failure
The world-first study below documents how MARS CT imaging can detect orthopedic implant failure not detected by standard current imaging techniques. MARS CT was shown to identify polyethylene insert and metallic tibial tray wear as a cause of TKA (total knee arthroplasty) failure.
- Lau, L.C.M, et al., (2021). Multi-energy spectral photon-counting computed tomography (MARS) for detection of arthroplasty implant failure. Scientific Reports, vol. 11, 1554. https://doi.org/10.1038/s41598-020-80463-2: Read paper
Measure multiple contrast agents simultaneously
CT has traditionally been limited to the use of a single contrast agent per scan. Spectral CT gives researchers a tool that can quantify a number of contrast agents as well as intrinsic markers such as lipid, bone and soft tissue. Tracking multiple biomarkers simultaneously provides a way to monitor multiple processes non-invasively.
Available data sets include mouse data and phantom data.
- R. Panta, et al., (2018). Element-specific spectral imaging of multiple contrast agents: a phantom study. Journal of Instrumentation. 13 T02001. Read paper.
- M. Moghiseh, et al., (2016). Discrimination of Multiple High-Z Materials by Multi-Energy Spectral CT– A Phantom Study. JSM Biomed Imaging Data Pap 3(1): 1007. Read paper.
- N. Anderson, et al., (2010). Spectroscopic (multi-energy) CT distinguishes iodine and barium contrast material in MICE. European Radiology, vol. 20, pp. 2126–2134. Read paper.
- R .K. Roeder, et al., (2017). Probes for Molecular Imaging with Computed Tomography and Application to Cancer Imaging. Proc. SPIE, 10132, 101320X. Read paper.
A mouse model of multiple contrast agents
Gold nanoparticles located in the lungs, iodine found in the bladder and kidneys, and gadolinium in the stomach and intestines. Soft tissues are identified in blue and bones in white.
Better monitoring of drug delivery
Imaging specific binding of antibody-gold nanoparticle complexes in vitro
MARS scanning opens the door to targeted imaging probes on CT.
Knowing whether an antibody-based treatment has reached its target tissue can be difficult. MARS spectral CT offers a method to track nanoparticles, allowing preclinical researchers to have confidence that their treatment has reached their target cells.
(a), (b), (c) calibration standards of gold chloride
(d) HER2 positive breast cancer cells incubated with gold nanoparticles functionalized with monoclonal antibody Herceptin
(e) HER2 positive breast cancer cells incubated with gold nanoparticles functionalized with monoclonal antibody Rituximab Rituximab
- M. Moghiseh, et al., (2018). Spectral photon-counting Molecular Imaging for Quantification of Monoclonal Antibody-Conjugated Gold Nanoparticles Targeted to Lymphoma and Breast Cancer: An In Vitro Study. Contrast media & molecular imaging. Read paper.
Better characterization of tumors
Lighting up tumor neovascularization using nanoparticles
A tumor was placed under the flank of the animal. Small gold nanoparticles (5 nm) were injected. The non-functionalized nanoparticles accumulate in areas of neovascularization (e.g. tumors) where vessels are leakier.
Targeted probes for micro-calcifications in breast cancer
Case Study: researchers at the University of Notre Dame have successfully targeted breast microcalcification using modified gold nanoparticles in a mouse model. MARS scanning of excised tissue showed co-localization of the gold nanoparticles and microcalcification.
- R. Roeder, (2017). Nanoparticle imaging probes for molecular imaging with computed tomography and application to cancer imaging. Vol. 10132, p. 101320X. International Society for Optics and Photonics. DOI: Read paper.
Develop targeted imaging probes
Functionalized nanoparticles targeted to bone micro-fractures
Identification and quantification of a novel hafnia-based functionalized nanoparticle. Hafnia-based nanoparticles highlighted bone microdamage in an excised human finger bone (left) and rat specimens (middle). Further, functionalized nanoparticles were evaluated versus non-functionalized nanoparticles. This study was in collaboration with the University of Maryland, Baltimore, USA and the University of Illinois at Urbana–Champaign, Urbana, USA.
- F. Ostadhossein, et al,. (2020). Multi‐“Color” Delineation of Bone Microdamages Using Ligand‐Directed Sub‐5 nm Hafnia Nanodots and Photon Counting CT Imaging. Vol. 30. No. 4. Advanced Functional Materials. Read paper
Improved soft tissue discrimination
Spectral imaging provides better soft tissue contrast than is available with traditional x-ray systems. This enables imaging and distinguishing pathological features of cardiovascular disease at high spatial resolution, for example the components of atherosclerotic plaque. Alternatively it can be used to better characterize muscles, bone and fat.
Downloadable data set of lamb meat.
- H. Prebble, et al., (2018). Induced macrophage activation in live excised atherosclerotic plaque. Immunobiology, vol. 223, no. 8-9, p. 526-535. Read paper.
- R. Aamir, et al., (2005). MARS spectral molecular imaging of lamb tissue: data collection and image analysis. Journal of Instrumentation, vol. 9, no. 02, p. P02005. Read paper.
Profiles of lipid (beige), calcium (white) and soft tissue (red) in lamb steak (left) and excised atherosclerotic plaque (right).
With high-resolution and high-soft tissue contrast of MARS material images, the local increased attenuation (due to increased density of parenchyma) in the lung may be identified and quantified earlier and more accurately than conventional CT images. This improves the detectability of ground-glass opacities, crazy paving appearances and air space consolidation which are important radiographic features in the diagnosis of tuberculosis and pneumonia.
Similarly, with high-resolution MARS attenuation images, peribronchovascular interstitial thickness, bronchial wall thickness and lumen size of bronchi and bronchioles may be measured more accurately than conventional CT images, which ultimately improve the detection of TB earlier.
Bone structural and material information in a single scan
MARS enables both structural, and material information to be measured simultaneously. This means that bone mineralization or bone densitometry can be measured within bone sites as well as architectural features such as cortical thickness, trabecular thickness, and trabecular spacing. Furthermore, some biomarkers of cartilage health can be measured including early measures of osteoarthritis.
Downloadable data sets include metallic scaffolds.
- M. R. Amma, et al., (2019). Assessment of metal implant induced artefacts using photon counting spectral CT. In Developments in X-Ray Tomography XII. Vol. 11113, p. 111131D. International Society for Optics and Photonics. DOI: Read paper.
- M. Ramyar, et al., (2017). Establishing a method to measure bone structure using spectral CT. SPIE Medical Imaging. DOI: 10.1117/12.2255616. Read paper.
- M. Ramyar, et al., (2017). Establishing a method to measure bone density using spectral CT. Published by the European Congress of Radiology. Read paper.
- K. Rajendran et al., (2014). Reducing beam hardening and metal artefacts in spectral CT using Medipix3RX. Journal of Instrumentation, Vol. 9 P03015. Read paper.
Joint health: Crystal arthritis
MARS provides multi-energy information and crystal type specific images of small joints with increased diagnostic value at higher spatial resolution (<80 µm) compared to traditional modalities.
(A) An excised gouty finger with a core (arrow) revealing subcutaneous Tophus. (B) Plain x-ray showing bone erosions with overhanging edges and soft tissue changes consistent with tophus. (C)Conventional dual-energy CT image and (D) high resolution MARS scanner, both depicting monosodium urate (MSU) crystal deposits, with MARS detecting finer detail and higher MSU volume. (E) Polarized light microscopy of a sample obtained from the core, confirming the presence of negatively birefringent MSU crystals.
- L. Stampet al., (2019). Clinical utility of multi‐energy spectral photon‐counting CT in crystal arthritis. Arthritis Rheumatol, 71: 1158-1162. doi:10.1002/art.40848. Read paper.
Characterization of atherosclerotic plaque in cardiovascular disease
The image to the left shows a carotid plaque from a patient who suffered a retinal (eye) stroke. A lipid-coated void is visible, possibly a previous rupture of the necrotic core. MARS reveals an intra plaque haemorrhage in blue along a densely calcified region.
The image on the right is an exposure rendered image of an excised human carotid atheroma at the bifurcation level showing lipid-like, calcium-like, and water-like material components. The darker the color hue, the greater the quantity of the component.