Evaluating the use of exposure indicators in digital x-ray imaging system: Gauteng South Africa

Feasibility of new patient dose management tool in digital radiography: Using clinical exposure index data of mobile chest radiography in a large university hospital

The clinical anteroposterior (AP) chest images taken with a mobile radiography system were analyzed in this study to utilize the clinical exposure index (EI) as a patient dose-monitoring tool. The digital imaging and communications in medicine header of 6048 data points exposed under the 90 kVp and 2.5 mAs were extracted using Python for identifying the distribution of clinical EI. Even under the same exposure conditions, the clinical EI distribution was 137.82-4924.38. To determine the cause, the effect of a patient's body shape on EI was confirmed using actual clinical chest AP image data binarized into 0 and 255-pixel values using Python. As a result, the relationship between the direct X-ray area of the chest AP image, the higher the clinical EI, the larger the rate of the direct X-ray area. A conversion equation was also derived to infer entrance surface dose through clinical EI based on the patient thickness. This confirmed the possibility of directly monitoring patient dose through EI without a dosimeter in real-time. Therefore, to use the clinical EI of the mobile radiography system as a patient dose-monitoring tool, the derivation method of clinical EI considers several factors, such as the relationship between patient factors.

Radiation Protection among South African Diagnostic Radiographers-A Mixed Method Study

ABSTRACT

Worldwide, radiographers' radiation protection practices vary. In South Africa, evidence of diagnostic radiographers' suboptimal radiation protection practices has been reported, but the reasons for these practices and suggestions to improve practices were lacking. Therefore, this study explored radiation protection among South African diagnostic radiographers. This study used an explanatory, sequential, mixed-method approach. Data were collected in three phases. Phase I, the quantitative phase, used an online questionnaire and respondents from Phase I interested in participating in Phase II, the qualitative phase, were interviewed, yielding 13 in-depth semi-structured telephone interviews. In Phase III, eight radiography managers co-constructed change strategies to optimize radiation protection in South Africa in two focus group interviews. Radiation protection was suboptimal despite diagnostic radiographers having a good attitude, subjective norm and perceived behavioral control toward radiation protection and optimal radiation protection knowledge. Varying attitudes to radiation protection, lack of resources, and support from radiography management and healthcare teams contributed to suboptimal radiation protection practices. Radiography managers suggested increasing radiation protection awareness, ameliorating the diminished stature of the radiographer in the healthcare team, and increasing the availability of optimal quality resources. South African diagnostic radiographers' radiation protection knowledge was optimal, but the implementation of radiation protection varied and was influenced by multiple factors. A radiation protection culture supported by management is advocated to optimize radiation protection. However, ultimately radiation protection practices are incumbent on the individual radiographers' choice to practice radiation protection.

South African radiographers' radiation protection practices, a qualitative study

INTRODUCTION

Radiation protection is multifarious, and consequently, a radiographers' application of radiation protection is multifaceted. Studies have shown varying radiation protection practices among radiographers. The first quantitative phase of this explanatory, sequential mixed-method study used the theory of planned behaviour to explore South African radiographers' radiation protection behaviour. Overall, South African radiographers' attitudes to radiation protection, subjective norm, perceived behavioural control, and radiation protection intention was high. This second phase of the study aimed to explore the reasons for South African radiographers' radiation protection practices.

METHODS

This study used an exploratory and descriptive qualitative approach. Data was collected through 13 in-depth semi-structured telephone interviews. Thematic analysis was used in order to uncover original phenomena. Data saturation was achieved and the study adhered to trustworthiness and ethical measures.

RESULTS

Thematic analysis identified two themes. The participants had the appropriate radiation protection knowledge, but radiation protection compliance remained a personal choice. Impediments such as feeling rushed during imaging of trauma and challenging patients, patients knowledge of radiation protection, resources, imaging referrals, inadequate training when transitioning from analogue to digital radiography and managerial support contributed to radiation protection compliance. Strategies such as further education, research and a change in mindset were suggested to further foster radiation protection compliance.

CONCLUSION

Even though participants' knowledge of radiation protection aligned with the legislated guidelines, limited internalising of the knowledge resulted in compliance being a personal choice. Participants reflected on their insouciant attitude and observed a similar attitude in their radiographer colleagues. Patient and work-related impediments were identified to contribute to radiation protection compliance. Strategies to further foster compliance were suggested.

IMPLICATIONS FOR PRACTICE

Understanding the reasons for radiographers' choice in radiation protection will allow the development of strategies that foster optimum application of radiation protection practises. Developing a radiation protection culture that enhances personal compliance supported by education and evidence should be considered.

Exploring the reliability of the exposure index with a range of kV and mAs values: An experimental study

INTRODUCTION

The exposure index (EI) is a numerical post-exposure tool that provides feedback to diagnostic radiographers undertaking digital X-ray examinations. The EI seeks to provide an indicator of the quantity of incident ionising radiation imparted on an image receptor. However, any large increase to X-ray intensity could interfere with the calculation of the EI. The aim of this paper was to evaluate detector overexposure by increasing X-ray beam intensity and quantifying the resultant effect on the EI.

METHODS

A porcine hip was purchased and exposed with varying tube potentials (50 to 110 kVp) and tube current-time products (5 to 100 mAs). Entrance surface dose (ESD) and EI values were determined for each exposure. For each acquisition parameter, two dose readings were collected. Linear regression was utilised to ascertain the relationship between the EI and varying tube exposures.

RESULTS

Tube exposures between 50 and 80 kVp demonstrated strong positive linear correlation coefficients (r = 0.993, p <0.001; r = 0.999, p <0.001; r = 0.983, p <0.001; r = 0.925, p <0.001) between ESD and EI. However, upon increasing tube exposures (90 to 110 kVp), interference with the EI calculation was demonstrated, which impacted both linearity, strength and direction of correlation (90 kVp r = 0.083, p = .248; 100 kVp r = -0.066, p = .479; 110 kVp r = -0.110, p = .601). Consequently, the use of higher tube exposures demonstrated variability with the EI by not demonstrating an expected positive linear relationship, which remained the initial expectation in this study.

CONCLUSION

The EI value is generally associated with providing reliable feedback to radiographers, yet this paper identifies some unexpected findings at high tube exposures (90 to 110 kVp). In short, this experiment provides insight that the EI value demonstrates inconsistent values within certain energy ranges.

IMPLICATIONS FOR PRACTICE

The findings have implications because it identifies variability of EI values at higher tube exposures. EI values may, therefore, not be helpful in providing meaningful feedback to radiographers when making changes to exposure factors.

Using the theory of planned behaviour to determine radiation protection among South African diagnostic radiographers: a cross-sectional survey

Introduction

The use of ionising radiation in medicine accounts for the majority of radiation exposure from artificial sources. Therefore, all measures to safeguard against unnecessary radiation exposure must be taken. As radiographers are central to radiation protection, this study aimed to determine South African radiographers’ attitude towards radiation protection, subjective norm and perceived behavioural control concerning radiation protection.

Methods

This quantitative cross‐sectional study used an online theory of a planned behaviour radiation protection questionnaire shared through social media platforms from August 2019 to February 2020. Diagnostic radiographers registered with the Health Professions Council of South Africa and employed at radiology departments in South Africa were invited to participate in the study.

Results

Four hundred and seventeen radiographers in South Africa responded to the questionnaire. The majority of respondents (90%, n = 376) plan to use radiation protection; however, only 16% continuously used radiation protection in the past. Respondents felt that using radiation protection was extremely good (72.2%), pleasant (47%), beneficial (74.1%), rewarding (55.2%) and worth the time (52.5%); 57% of respondents indicated that using radiation protection takes longer to complete the examination. Respondents report that approval from patients (43.5%), patients’ family (32%), radiographer coworkers (31%), radiology managers (47%) and radiologists (43.9%) is very much important to them.

Conclusion

The study shows that even though fewer respondents use radiation protection at present, most respondents plan and intend to use radiation protection measures. Respondents felt that radiation protection was good and beneficial, with some respondents feeling that radiation protection is not worth the time, which coincide with lengthening the examination. Overall, South African radiographers’ attitudes towards radiation protection, subjective norm, perceived behavioural control and radiation protection intention were high.