FEASIBILITY OF DISPLAYED EXPOSURE INDEX IN IEC STANDARD FRAMEWORK AS A DOSE OPTIMISATION TOOL FOR DIGITAL RADIOGRAPHY SYSTEMS

Abstract International Electrotechnical Commission (IEC) established the framework for the use of exposure index (EI) for evaluating the exposure conditions with various digital systems. In this study, we investigated the feasibility of EI, as per the IEC, by comparing the EIs obtained through manual calculated and that displayed on the console of two computed radiography (CR) and digital radiography (DR) systems with radiation beam qualities of RQA3,5,7 and 9. As a result, both two systems indicated an uncertainty of less than 20% for both calculated and displayed EI with all beam qualities except displayed EI obtained by RQA3. However, the displayed EI values were different even under the same exposure conditions because of the characteristics of the imaging receptor materials, such as BaFI or CsI, of two systems. Therefore, when an operator attempts to introduce displayed EI for managing radiation dose, it is essential to understand the characteristics of the digital system.

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USE OF CLINICAL EXPOSURE INDEX AND DEVIATION INDEX BASED ON NATIONAL DIAGNOSTIC REFERENCE LEVEL AS DOSE-OPTIMIZATION TOOLS FOR GENERAL RADIOGRAPHY IN KOREA

Radiation Protection Dosimetry ◽

10.1093/rpd/ncaa185 ◽

2020 ◽

Vol 191 (4) ◽

pp. 439-451

Author(s):

Hyemin Park ◽

Yongsu Yoon ◽

Jungmin Kim ◽

Jungsu Kim ◽

Hoiwoun Jeong ◽

...

Keyword(s):

Patient Dose ◽

Reference Level ◽

Dose Optimization ◽

International Electrotechnical Commission ◽

Exposure Index ◽

Clinical Exposure ◽

Deviation Index ◽

Clinical Environments ◽

Anterior Posterior ◽

Exposure Conditions

Abstract The International Electrotechnical Commission introduced the concepts of exposure index (EI), target exposure index (EIT) and deviation index (DI) to manage and optimize patient dose in real time. In this study, we have proposed an appropriate method for setting the EIT based on the Korean national diagnostic reference levels (DRLs). Furthermore, we evaluated the use of clinical EI, EIT and DI as tools for patient dose optimization in clinical environments by observing the changes in DI with those in EIT. According to the Korean national exposure conditions, we conducted experiments on three representative radiographic examinations (chest posterior–anterior, lateral and abdomen anterior–posterior) of clinical environments. As the exposure conditions and DRLs varied, the clinical EI, EIT and DI also varied. These results reveal that the clinical EI, EIT and DI can be used as tools for optimizing the patient dose if EIT is periodically and properly updated.

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Proper Management of the Clinical Exposure Index Based on Body Thickness Using Dose Optimization Tools in Digital Chest Radiography: A Phantom Study

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18105203 ◽

2021 ◽

Vol 18 (10) ◽

pp. 5203

Author(s):

Yongsu Yoon ◽

Hyemin Park ◽

Jungmin Kim ◽

Jungsu Kim ◽

Younghoon Roh ◽

...

Keyword(s):

Digital Radiography ◽

Chest Radiography ◽

Exposure Dose ◽

Dose Optimization ◽

International Electrotechnical Commission ◽

Exposure Condition ◽

Exposure Index ◽

Lateral Projection ◽

Exposure Indicator ◽

Digital Chest

In radiography, the exposure index (EI), as per the International Electrotechnical Commission standard, depends on the incident beam quality and exposure dose to the digital radiography system. Today automatic exposure control (AEC) systems are commonly employed to obtain the optimal image quality. An AEC system can maintain a constant incident exposure dose on the image receptor regardless of the patient thickness. In this study, we investigated the relationship between body thickness, entrance surface dose (ESD), EI, and the exposure indicator (S value) with the aim of using EI as the dose optimization tool in digital chest radiography (posterior–anterior and lateral projection). The exposure condition from the Korean national survey for determining diagnostic reference levels and two digital radiography systems (photostimulable phosphor plate and indirect flat panel detector) were used. As a result, ESD increased as the phantom became thicker with constant exposure indicator, which indicates similar settings to an AEC system, but the EI indicated comparatively constant values without following the tendency of ESD. Therefore, body thickness should be considered under the AEC system for introducing EI as the dose optimization tool in digital chest radiography.

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