3D-Printed Coronary Plaques to Simulate High Calcification in the Coronary Arteries for Investigation of Blooming Artifacts.

The diagnostic value of coronary computed tomography angiography (CCTA) is significantly affected by high calcification in the coronary arteries owing to blooming artifacts limiting its accuracy in assessing the calcified plaques. This study aimed to simulate highly calcified plaques in 3D-printed coronary models. A combination of silicone + 32.8% calcium carbonate was found to produce 800 HU, representing extensive calcification. Six patient-specific coronary artery models were printed using the photosensitive polyurethane resin and a total of 22 calcified plaques with diameters ranging from 1 to 4 mm were inserted into different segments of these 3D-printed coronary models. The coronary models were scanned on a 192-slice CT scanner with 70 kV, pitch of 1.4, and slice thickness of 1 mm. Plaque attenuation was measured between 1100 and 1400 HU. Both maximum-intensity projection (MIP) and volume rendering (VR) images (wide and narrow window widths) were generated for measuring the diameters of these calcified plaques. An overestimation of plaque diameters was noticed on both MIP and VR images, with measurements on the MIP images close to those of the actual plaque sizes (<10% deviation), and a large measurement discrepancy observed on the VR images (up to 50% overestimation). This study proves the feasibility of simulating extensive calcification in coronary arteries using a 3D printing technique to develop calcified plaques and generate 3D-printed coronary models.

Evaluation of academic integrity of online open book assessments implemented in an undergraduate medical radiation science course during COVID-19 pandemic.

INTRODUCTION: Online open book assessment has been a common alternative to a traditional invigilated test or examination during the COVID-19 pandemic. However, its unsupervised nature increases ease of cheating, which is an academic integrity concern. This study's purpose was to evaluate the integrity of two online open book assessments with different formats (1. Tightly time restricted - 50 min for mid-semester and 2. Take home - any 4 h within a 24-h window for end of semester) implemented in a radiologic pathology unit of a Bachelor of Science (Medical Radiation Science) course during the pandemic. METHODS: This was a retrospective study involving a review and analysis of existing information related to the integrity of the two radiologic pathology assessments. Three integrity evaluation approaches were employed. The first approach was to review all the Turnitin plagiarism detection software reports with use of 'seven-words-in-a-row' criterion to identify any potential collusion. The second approach was to search for highly irrelevant assessment answers during marking for detection of other cheating types. Examples of highly irrelevant answers included those not addressing question requirements and stating patients' clinical information not from given patient histories. The third approach was an assessment score statistical analysis through descriptive and inferential statistics to identify any abnormal patterns that might suggest cheating occurred. An abnormal pattern example was high assessment scores. The descriptive statistics used were minimum, maximum, range, first quartile, median, third quartile, interquartile range, mean, standard deviation, fail and full mark rates. T-test was employed to compare mean scores between the two assessments in this year (2020), between the two assessments in the last year (2019), between the two mid-semester assessments in 2019 and 2020, and between this and last years' end of semester assessments. A p-value of less than 0.05 was considered statistically significant. RESULTS: No cheating evidence was found in all Turnitin reports and assessment answers. The mean scores of the end of semester assessments in 2019 (88.2%) and 2020 (90.9%) were similar (p = 0.098). However, the mean score of the online open book mid-semester assessment in 2020 (62.8%) was statistically significantly lower than that of the traditional invigilated mid-semester assessment in 2019 (71.8%) with p < 0.0001. CONCLUSION: This study shows the use of the online open book assessments with tight time restrictions and the take home formats in the radiologic pathology unit did not have any academic integrity issues. Apparently, the strict assessment time limit played an important role in maintaining their integrity.

National survey of Australian sonographer knowledge and behaviour surrounding the ALARA principles when conducting the 11-14-week obstetric screening ultrasound.

OBJECTIVES: To identify gaps in Australian sonographer's knowledge and application of as low as reasonably achievable (ALARA) principles during first trimester imaging; Identify relationships between demographic variables and knowledge or application of the Output Display Standard (ODS) value thermal index (TI) and compare Australian sonographers to their international peers. METHODS: Australian Sonographer Accreditation Registered ( ASAR)-registered sonographers completed a voluntary questionnaire over September 2015 after institutional ethics approval (RDSE-48-15). Seventeen questions detailed their demographics (5); knowledge of ultrasound bioeffects terminology and ALARA principles (9); behaviour surrounding ALARA and first trimester imaging (2) and continuing bioeffects education (1). Exclusion criteria was non-ASAR status. Descriptive (mode frequency) and inferential statistics (Fisher exact test) were used. Significance level was 95%. RESULTS: Ninety-five valid surveys were collected. Ninety-nine per cent knew the meaning of ALARA, 93.55% correctly defined 'TI' and 85.39% knew where to find the TI value via the ODS. Half never monitor the ODS. No correlation (P = 0.094) was found between experience and ODS monitoring. No statistical difference (P = 0.189) existed between obstetric and non-obstetric sonographers who knew the meaning of TIB (87.18% vs. 76.92%) or those who correctly identified it as the setting for 11-14-week examinations (30.77% vs. 30.77%). When using Doppler during obstetric examinations, no difference existed (P = 0.293), between obstetric and non-obstetric sonographers' knowledge of ASUM/WFUMB guidelines for maximum TI (47.37% vs. 46.15%). CONCLUSIONS: Despite poor ODS usage, Australian sonographers outperform their international peers for ALARA literacy, and show better application of ALARA principles in the first trimester. No relationships were found between demographic variables and knowledge or conscious monitoring of ODS.

Pediatric Computed Tomography Dose Optimization Strategies: A Literature Review.

INTRODUCTION: Computed tomography (CT) dose optimization is an important issue in radiography because CT is the largest contributor to medical radiation dose and its use is increasing. However, CT dose optimization for pediatric patients could be more challenging than their adult counterparts. The purpose of this literature review was to identify and discuss the current pediatric CT dose saving techniques. Optimized pediatric protocols were also proposed. METHODS: A comprehensive literature search was conducted using the Medline, ProQuest Health and Medical Complete, PubMed, ScienceDirect, Scopus, Springer Link, and Web of Science databases and the keywords CT, pediatric, optimization, protocol, and radiation dose to identify articles focusing on pediatric CT dose optimization strategies published between 2004 and 2014. RESULTS AND SUMMARY: Seventy-seven articles were identified in the literature search. Strategies for optimizing a range of scan parameters and technical considerations including tube voltage and current, iterative reconstruction, diagnostic reference levels, bowtie filters, scout view, pitch, scan collimation and time, overscanning, and overbeaming for pediatric patients with different ages and body sizes and compositions were discussed. An example of optimized pediatric protocols specific to age and body size for the 64-slice CT scanners was devised. It is expected that this example could provide medical radiation technologists, radiologists, and medical physicists with ideas to optimize their pediatric protocols.

Study of lone working magnetic resonance technologists in Western Australia.

OBJECTIVES: It is recommended that magnetic resonance (MR) technologists should not work alone due to potential occupational health risks although lone working is legally acceptable. The objective of this study was to investigate the current situation of lone working MR technologists in Western Australia (WA) and any issue against the regulations. MATERIALS AND METHODS: A questionnaire regarding the issues of occupational health of lone working MR technologists was developed based on relevant literature and distributed to WA MR technologists. Descriptive (percentage of frequency, mean and standard deviation) and inferential statistics (Fisher's exact, Chi(2) and t tests, and analysis of variance) were used to analyze the responses of the yes/no, multiple choice and 5 pt scale questions from the returned questionnaires. RESULTS: The questionnaire response rate was 65.6% (59/90). It was found that about half of the MR technologists (45.8%, 27/59) experienced lone working. The private magnetic resonance imaging (MRI) centers were more likely to arrange technologists to work alone (p < 0.05). The respondents expressed positive views on issues of adequacy of training and arrangement, confidence and comfort towards lone working except immediate assistance for emergency (mean: 3). Factors of existence of MRI safety officer (p < 0.05) and nature of lone working (p < 0.001-0.05) affected MR technologists' concerns. CONCLUSIONS: Lone working of MR technologists is common in WA especially in private centers. The training and arrangement provided seem to be adequate for meeting the legal requirements. However, several areas should be improved by the workplaces including enhancement on immediate emergency assistance and concern relief.

Pain Controlling and Cytokine-regulating Effects of Lyprinol, a Lipid Extract of Perna Canaliculus, in a Rat Adjuvant-induced Arthritis Model.

Using an adjuvant-induced arthritis rat model, we investigated the effects of a lipid extract of Perna canaliculus (Lyprinol(R)) on pain. Radiological examinations, as well as levels of pro- and anti-inflammatory (AI) cytokines, were measured aiming to provide independent objective data to the pain controlling investigation. We confirmed the ability of Lyprinol(R) to control pain at the initial phase of its administration; with similar efficacy to that observed with Naproxen. The pain scores slowly increased again in the group of rats treated with Lyprinol(R) after day 9-14. The Naproxen-treated rats remained pain-free while treated. Both Naproxen and Lyprinol(R) decreased the levels of the pro-inflammatory cytokines TNF-alpha and IFN-gamma, and increased that of IL-10. Extra-virgin olive oil was ineffective on cytokine secretion. Rats treated with Lyprinol(R) were apparently cured after 1 year. This study confirms the AI efficacy of this lipid extract of P. canaliculus, its initial analgesic effect, its perfect tolerance and its long-term healing properties.