Terence Riauka

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Lung cancer represents the most deadly type of malignancy. In this work we propose a machine learning approach to segmenting lung tumours in Positron Emission Tomography (PET) scans in order to provide a radiation therapist with a " second reader " opinion about the tumour location. For each PET slice, our system extracts a set of attributes, passes them to(More)
Compared with slice-by-slice approaches for SPECT reconstruction, three-dimensional iterative methods provide a more accurate physical model and an improved SPECT image. Clinical application of these methods, however, is limited primarily to their computational demands. This paper investigates the methods for approximate 3D iterative reconstruction that(More)
We applied a learning methodology framework to assist in the threshold-based segmentation of non-small-cell lung cancer (NSCLC) tumours in positron-emission tomography-computed tomography (PET-CT) imaging for use in radiotherapy planning. Gated and standard free-breathing studies of two patients were independently analysed (four studies in total). Each(More)
A new method to correct for attenuation and the buildup of scatter in planar imaging quantification is presented. The method is based on the combined use of 3D density information provided by computed tomography to correct for attenuation and the application of Monte Carlo simulated buildup factors to correct for buildup in the projection pixels. CT and(More)
Increasingly, fractals are being incorporated into pharmacokinetic models to describe transport and chemical kinetic processes occurring in confined and heterogeneous spaces. However, fractal compartmental models lead to differential equations with power-law time-dependent kinetic rate coefficients that currently are not accommodated by common commercial(More)
Noise levels observed in positron emission tomography (PET) images complicate their geometric interpretation. Post-processing techniques aimed at noise reduction may be employed to overcome this problem. The detailed characteristics of the noise affecting PET images are, however, often not well known. Typically, it is assumed that overall the noise may be(More)
It is demonstrated that birdcage resonators, satisfying conditions of quadrature operation and radiofrequency field homogeneity, can be realized in practice on formers of non-circular cross section described by an equation of the form (x/a)n + (y/b)n = 1 where a and b are constants and n > or = 2 is an integer. Using a ladder network analogous to that of a(More)
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