The history of medical physics in Asia-Oceania goes back to the late nineteenth century when X-ray imaging was introduced, although medical physicists were not appointed until much later. Medical physics developed very quickly in some countries, but in others the socio-economic situation as such prevented it being established for many years. In others, the political situation and war has impeded its development. In many countries their medical physics history has not been well recorded and there is a danger that it will be lost to future generations. In this paper, brief histories of the development of medical physics in most countries in Asia-Oceania are presented by a large number of authors to serve as a record. The histories are necessarily brief; otherwise the paper would quickly turn into a book of hundreds of pages. The emphasis in each history as recorded here varies as the focus and culture of the countries as well as the length of their histories varies considerably.

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Dose metrics on intraoral and panoramic dental radiography were analyzed to preliminarily indicate dose trend of dental radiology equipment in Indonesia. Measurements were performed in 71 healthcare institutions involving a total of 92 dental X-ray devices. Imaging modes are categorized into 'low dose' and 'high dose' based on the task. The 75th percentile for intraoral IAK was 2.8 and 4.3 mGy for 'low' and 'high' dose modes, respectively while for panoramic devices the 75th percentile of the KAP for 'low' and 'high' dose modes were 85.2 and 192.4 mGy cm2, respectively. Results compared with local regulatory recommendation for intraoral units indicated that 38.8 and 6.3% of measured dose modes on analogue and digital devices, respectively, were above the recommended range. The dose trend can be used as reference for local regulations concerning patient dose in dental radiography and preliminary value prior to the establishment of national diagnostic reference level.

Optimization of imaging examinations is a key requirement of both the International and European Basic Safety Standards, and the focus of much international activity. Although methodologies are well established in principle, there continues to be a variety of practical issues both in collecting and interpreting dose and image quality data and in making successful interventions to optimize exposures. A Coordinated Research Project, involving institutes from ten different countries, was established by the IAEA to assess the efficacy of recommended optimization methodologies in the field of paediatric radiology and to derive practical guidance on their implementation. The steps followed in this process were identification of the imaging process to be investigated (abdomen and chest x-rays, micturating cysto-urethrograms, and brain & thorax CT scans); collection of dose and image quality data; evaluation and comparison of the data between institutes and to standards; identification and implementation of interventions for optimization; and reevaluation of dose and image quality parameters. The project succeeded both in achieving effective interventions for optimization of specific imaging tasks in individual institutes and in identifying key issues with potential to handicap this process. The main area in which problems were encountered was in the collation of reliable dose and image quality data. The reasons for this were explored and a series of recommendations have been made, summarized into 'ten practical tips' for optimization to assist institutes, particularly those in the early stages of addressing optimization issues.

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The use of computed tomography (CT) has become a common practice in medical diagnosis in Indonesia. Its number, however, is not matched by the availability of dedicated-performance-check phantoms. This paper aims to describe the design, construction, and evaluation of an in-house phantom for CT performance check that accommodates both radiation dose measurement and image quality performance checks. The phantom is designed as laser-cut polymethyl methacrylate (PMMA) slabs glued together to form a standard cylindrical shape, with spaces to place dose measurement and image quality modules. In this paper, measurement results on both aspects are discussed and compared with standard phantoms and other works. For dose measurement, the constructed phantom exhibited the greatest absolute discrepancy against the reference standard phantom of 8.89 %. Measurement of the CT number linearity and modulation transfer function (MTF) yielded, at most, 7.51 % and 5.07 % discrepancies against Catphan 604, respectively. Meanwhile, although found to be more linear in the phantom-based contrast linearity test, the use of the in-house phantom for clinical image contrast threshold determination requires further study. For noise power spectrum (NPS) measurement, accurate results were obtained within a limited range of spatial frequency.

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