Monitoring clinical exposure index and deviation index for dose optimization based on national diagnostic reference level: Focusing on general radiography of extremities

Abstract

BACKGROUND: The International Electrotechnical Commission established the concept of the exposure index (EI), target exposure index (EIT) and deviation index (DI). Some studies have conducted to utilize the EI as a patient dose monitoring tool in the digital radiography (DR) system. OBJECTIVE: To establish the appropriate clinical EIT, this study aims to introduce the diagnostic reference level (DRL) for general radiography and confirm the usefulness of clinical EI and DI. METHODS: The relationship between entrance surface dose (ESD) and clinical EI is obtained by exposure under the national radiography conditions of Korea for 7 extremity examinations. The EI value when the ESD is the DRL is set as the clinical EIT, and the change of DI is then checked. RESULTS: The clinical EI has proportional relationship with ESD and is affected by the beam quality. When the clinical EIT is not adjusted according to the revision of DRLs, there is a difference of up to 2.03 in the DI value and may cause an evaluation error of up to 1.6 time for patient dose. CONCLUSIONS: If the clinical EIT is periodically managed according to the environment of medical institution, the appropriate patient dose and image exposure can be managed based on the clinical EI, EIT, and DI.

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

“…This is defined as the calibration of EI, and applies equally to all DR system manufacturers [ 14 ]. Accordingly, EI is proportional to the incident dose on the detector [ 12 , [14] , [15] , [16] , [17] , [18] ]. The IEC standard notes that the EI may differ for each manufacturer and each type of examination in clinical protocols, but the proportional relationship with the incident dose on the detector does not change [ 12 ].…”

“…In general radiography, the DAP serves as an indicator for monitoring patient dose, and it can be conveniently measured using a DAP meter during patient examinations. However, the ESD cannot be measured using a dosimeter when examining patients; thus, it is difficult to identify in real-time [ 17 , [24] , [25] , [26] , [27] , [28] ]. The approach taken in this study, which involves inferring ESD through clinical EI, provides a means to monitor patient dose in real time without needing a dosimeter during the examination.…”

“…Previous studies are being conducted to monitor the patient dose using EI as per the IEC standard [ [14] , [15] , [16] , [17] , [18] ]. This study conducted, additional experiments to utilize clinical EI to monitor the patient dose.…”

“…Therefore, the clinical EI values for each examination protocol may differ for each manufacturer [ 15 , 16 ]. However, the clinical EI also shows a proportional relationship with the incident dose on the detector [ 15 , 17 ]. Therefore, several studies have demonstrated the utility of the EI as a real-time dose-monitoring tool [ [14] , [15] , [16] , [17] , [18] ].…”

“…A previous study reported that the EI could be used as a quality control tool for the detector through the relationship between EI and air kerma incident on the detector under radiation beam quality (RQA) 5, a calibration condition according to the IEC standard [ 14 ]. In addition, the possibility of using clinical EI as a dose-monitoring tool was suggested by setting an appropriate target exposure index (EI T ) based on national diagnostic reference levels (DRLs) [ 15 , 17 ]. A study was conducted on the considerations when using EI as a dose monitoring tool in clinical practice through the change in EI according to the patient's thickness in an environment where an automatic exposure control (AEC) system is applied [ 18 ].…”