Research highlights and societal impact

Professor Meikle's most distinguished contributions to the field of medical imaging are in quantitative emission computed tomography and small animal imaging instrumentation.

His work on positron emission tomography (PET), which began in the early 1990s, addressed the major challenges in whole body PET at that time – the lack of suitable methods for transmission scanning and algorithms for performing attenuation correction and image reconstruction in the presence of very high noise. Prior to these developments, whole body PET was a non-quantitative procedure. While working as a visiting scientist at the UCLA School of Medicine, Professor Meikle developed a novel image segmentation algorithm that transforms noisy attenuation images into a noiseless correction for photon attenuation in the body, making it feasible to perform transmission scans of very short duration. After returning to Sydney, he performed experiments that demonstrated the improvement in image quality (due to enhanced noise properties) and lesion detection resulting from the use of iterative image reconstruction in whole body PET. These methodologies are now used in routine clinical practice throughout the world for cancer staging and evaluation of response to treatment.

He also developed a scatter correction method for single photon emission computed tomography (SPECT), which was the first to model variable tissue density in the thorax, an essential requirement for accurate imaging of the heart and lungs. The method was incorporated into a software package, which is currently undergoing the world’s first multi-centre clinical trial in Japan of the utility of quantitative SPECT for assessing the viability of damaged heart muscle.

More recently, Professor Meikle proposed a method to increase the sensitivity of small animal SPECT systems, which has spawned research by several groups and three commercial companies (BioScan, Gamma Medica-Ideas, Siemens Medical Solutions), who are further developing and refining the technology. The technology is used to evaluate promising drug treatments for cancer and neuropsychiatric conditions in animal models of human disease.