10 results for Anderson, N.

  • Feasibility of biomedical spectroscopic x-ray imaging with Medipix

    Butler, A.; Cook, N.; Watts, R.; Bell, A.; Anderson, N.; Tipples, R.; Butler, P.; MARS-CT Team (2008)

    Conference Contributions - Other
    University of Canterbury Library

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  • Applying CERN’s detector technology to health: MARS Biomedical 3D spectroscopic x-ray imaging

    Butler, P.H.; Bell, A.J.; Butler, A.P.H.; Cook, N.J.; Reinisch, L.; Butzer, J.S.; Anderson, N.; MARS-CT Team (2008)

    Conference Contributions - Published
    University of Canterbury Library

    New Zealand has benefited considerably from our links with the European Centre for Nuclear Research (CERN). We have been an associate member of CERN for 8 years, with projects in high energy physics theory, in the high energy physics Compact Muon Solenoid (CMS) experiment, and in technology development. In 2006 we joined the Medipix-3 Collaboration. We have installed Medipix detectors in the CMS Cavern for monitoring neutrons and ionising radiation. Our major effort has been to build Medipix detectors into a 3D x-ray scanner of our design. The scanner is dubbed Desktop MARS (Medipix All Resolution system) and provides energy selective images of small biological and pathology specimens. This paper reviews several matters. We look at the support given by the NZ government who have seen benefits in our involvement, including skill development, economic and commercial opportunities, and in overcoming the isolation of distance. We review NZ’s particular role in CMS where particle physics is a driver of new technology; We explore the opportunities arising from Medipix as the first photon processing detector. We first summarise the design of the Medipix detector and discuss likely benefits of spectroscopic imaging in clinical radiology. CERN and the Medpiox-3 Collaboration have licensed us to commercialise the technology for biomedical imaging of small animals and humans using the Medipix detector as the key tool for obtaining 3D computed tomography spectroscopic x-ray CT images. Finally we present some images of biological specimens taken with the MARS scanner, including initial spectroscopic images of mice.

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  • MARS: a 3D Spectroscopic X-Ray Imaging Device Based on Medipix

    Butzer, J.S.; Butler, A.P.H.; Cook, N.J.; Butler, P.H.; Ross, F.; Schleich, N.; Selkirk, J.; Watts, R.; Meyer, J.; Scott, N.; Bones, P.J.; van Leeuwen, D.; Hemmingsen, S.; Melzer, T.P.; Anderson, N.; MARS-CT Team (2008)

    Conference Contributions - Other
    University of Canterbury Library

    A spectroscopic x-ray CT scanner, providing both spatial and energy resolution was built. Tomographic datasets from mice have been acquired to evaluate the potential benefits of spectroscopic imaging in biomedical applications.

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  • Identifying Clinical applications of Spectroscopic x-ray imaging

    Butler, A.P.H.; Anderson, N.; Cook, N.; Butler, P.; MARS-CT Team (2008)

    Conference Contributions - Other
    University of Canterbury Library

    Spectroscopic x-ray detectors, such as Medipix, are opening the door to the widespread use of energy selective biomedical x-ray imaging. With dual energy computed tomography quickly becoming the clinical standard, spectroscopic imaging is a likely next step. However to confirm the utility of spectroscopic x-ray detectors there needs to be a clearer indication of the clinical benefits of the technology.

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  • Spectroscopic biomedical imaging with the Medipix2 detector

    Melzer, T.R.; Cook, N.J.; Butler, A.P.H.; Watts, R.; Anderson, N.; Tipples, R.; Butler, P.H.; MARS-CT Team (2008)

    Journal Articles
    University of Canterbury Library

    This study confirms that the Medipix2 x-ray detector enables spectroscopic bio-medical plain radiography. We show that the detector has the potential to provide new, useful information beyond the limited spectroscopic information of modern dual-energy computed tomography (CT) scanners. Full spectroscopic 3D-imaging is likely to be the next major technological advance in computed tomography, moving the modality towards molecular imaging applications. This paper focuses on the enabling technology which allows spectroscopic data collection and why this information is useful. In this preliminary study we acquired the first spectroscopic images of human tissue and other biological samples obtained using the Medipix2 detector. The images presented here include the clear resolution of the 1.4mm long distal phalanx of a 20 week old miscarried foetus, showing clear energy-dependent variations. The opportunities for further research using the forthcoming Medipix3 detector are discussed and a prototype spectroscopic CT scanner (MARS, Medipix All Resolution System) is briefly described.

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  • Dosimetry for spectral molecular imaging of small animals with MARS-CT

    Ganet, N.; Anderson, N.; Bell, S.; Butler, A.; Butler, P.; Carbonez, P.; Cook, N.; Cotterill, T.; Marsh, S.; Kumar, R.; Laban, J.; Walker, S.; Yeabsley, A.; Damet, J. (2015)

    Conference Contributions - Published
    University of Canterbury Library

    The Medipix All Resolution Scanner (MARS) spectral CT is intended for small animal, pre-clinical imaging and uses an x-ray detector (Medipix) operating in single photon counting mode. The MARS system provides spectrometric information to facilitate differentiation of tissue types and bio-markers. For longitudinal studies of disease models, it is desirable to characterise the system’s dosimetry. This dosimetry study is performed using three phantoms each consisting of a 30 mm diameter homogeneous PMMA cylinder simulating a mouse. The imaging parameters used for this study are derived from those used for gold nanoparticle identification in mouse kidneys. Dosimetry measurement are obtained with thermo-luminescent Lithium Fluoride (LiF:CuMgP) detectors, calibrated in terms of air kerma and placed at different depths and orientations in the phantoms. Central axis TLD air kerma rates of 17.2 (± 0.71) mGy/min and 18.2 (± 0.75) mGy/min were obtained for different phantoms and TLD orientations. Validation measurements were acquired with a pencil ionization chamber, giving an air-kerma rate of 20.3 (±1) mGy/min and an estimated total air kerma of 81.2 (± 4) mGy for a 720 projection acquisition. It is anticipated that scanner design improvements will significantly decrease future dose requirements. The procedures developed in this work will be used for further dosimetry calculations when optimizing image acquisition for the MARS system as it undergoes development towards human clinical applications.

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  • Spectroscopic Contrast-agent imaging with the Medipix CT-Scanner “MARS”

    Butzer, J.S.; Butler, A.P.H.; Butler, P.H.; Cook, N.J.; Schleich, N.; Firsching, M.; Scott, N.; Anderson, N.; Ross, F.; Watts, R.; Meyer, J.; van Leeuwen, D.; Selkirk, J.; Bones, P.J.; MARS-CT Team (2008)

    Conference Contributions - Other
    University of Canterbury Library

    The prototype MARS (Medipix All Resolution System) x-ray CT scanner provides spatial and energy resolution at the same time. It is currently operated at Christchurch Hospital to evaluate the clinical potential of spectroscopic images. The first datasets with a focus on contrast-agent imaging have been processed.

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  • Diurnal, weekly, and seasonal variations in stroke occurrence in a population-based study in Auckland, New Zealand

    Anderson, N.; Feigin, V.; Bennett, D.; Broad, J.; Pledger, M.; Anderson, C.; Bonita, R. (2004)

    Journal article
    The University of Auckland Library

    An open access copy of this article is available and complies with the copyright holder/publisher conditions. Aims: To determine (via a population-based study in Auckland, New Zealand) if there are diurnal, weekly, or seasonal variations in the occurrence of stroke. Methods: All new stroke events in Auckland residents were traced. Time of onset of the stroke was defined as the time when neurological symptoms were first noticed. The day of the week and month of onset were analysed for all strokes. Results: 1711 patients were registered over 1 year. The rate ratios for the onset of stroke in each 6-hourly interval compared with reference interval (1800-2359 hours) were 0.74 (95% CI: 0.61-1.10) for 0000-0559 hours, 2.88 (95% CI: 2.48-3.34) for 0600-1159 hours and 1.74 (95% CI: 1.49-2.05) for 1200-1759 hours. Rate ratios of the seasonal occurrence of stroke compared with spring were 0.75 (95% CI: 0.65-0.86) for summer, 0.83 (95% CI: 0.73-0.95) for autumn and 1.08 (95% CI: 0.96-1.23) for winter. No weekly pattern of stroke occurrence was observed. Conclusions: Strokes were less likely to occur during the summer and autumn than in the winter or spring. There was an increase in the occurrence of stroke in the late morning. The results have implications for the provision of acute stroke services in the community and in hospital.

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  • Changes in stroke care at Auckland hospital between 1996 and 2001

    Barber, P.A.; Charleston, A.; Anderson, N.; Spriggs, D.; Bennett, D.; Bennett, P.; Thomas, K.; Baker, Y. (2004)

    Journal article
    The University of Auckland Library

    An open access copy of this article is available and complies with the copyright holder/publisher conditions. Aims: In 1996, we performed a descriptive audit of stroke care in Auckland Hospital. Since then, a mobile stroke team has been established. We have repeated the 1996 audit to assess changes in stroke management. Methods: From 1 June to 30 September 2001, information was prospectively recorded for all patients with stroke. Results: There were 177 strokes in 175 patients (92 men, mean age 70.9, standard deviation [SD] 14.9 years). Ninety-seven percent of patients had cerebral imaging (median 4.5 hours; interquartile range [IQR] 2.7-11.6). Acute aspirin was given to 78% of patients in 2001 and 40% in 1996 (p of stroke care and use of therapies, which are shown to be of benefit in randomised controlled trials.

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  • Documentary analysis hui: an innovative research method employed to bring documents to life through culturally responsive conversation

    Cardno, Carol; Anderson, N.; McDonald, M. (2017-05-10T05:35:31Z)

    Conference item
    Unitec

    Kaupapa Māori research is collectivist – oriented towards benefitting all research participants and their agendas Self-determination is a key dimension – providing agentic positioning for research participants Māori language, culture, knowledge and values are accepted in their own right. ... In this case courage was needed to align research action with the principles of Kaupapa Māori research – namely agentic positioning, partnership, participation and respect for the knowledge of the participants.

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