Background and objectives: Digital radiography is a
common diagnostic practice and it has been a significant
increase in the number of x-ray examinations.
Patients were frequently exposed to radiation may
consider increasing the risk of exposure to radiation.
The purpose of this study was set up to evaluate the
entrance skin dose (ESD) in common digital radiography
in Srinagarind hospital, faculty of medicine, Khon
Kaen university and compared to ESD with national
and international diagnostic reference level (DRL)
including study of parameters which effect the ESD.
Material and method: The retrospective study was
conducted from January to May 2019 by using picture
achieving communication systems (PACS). The digital
radiographic parameters from total 1,010 patients from
12 examinations including chest, cervical spine, thoracic
spine and lumbar spine, skull in anteroposterior/
posteroanterior (AP/PA) view and lateral view, abdomen
and pelvis in AP view were recorded. The ESD
was calculated using the specific formula. All data
were analyzed using descriptive analysis and the
correlation of digital radiographic parameters and ESD
was also analyzed Result: The result showed that the highest kVp for DR
was observed in chest LAT while the highest mAs was
observed in lumbar spine LAT. The median ESD of all
digital radiography examination was lower than the
international IAEA DRL value while the median of ESD
of chest PA, abdomen AP, pelvis AP, lumbar spine LAT
and skull AP/PA was lower than Thai national DRL
except for the median ESD of lumbar spine AP and
skull LAT were higher than national DRL. Moreover,
the median ESD was compared with the Japanese and
United Kingdom (UK) DRL. The comparison between
ESD and Japanese DRL was showed the result like the
Thai national DRL. While the comparison between ESD
and UK DRL, the median ESD of abdomen AP, pelvis
AP and lumbar spine LAT were lower than UK DRL
except for the median ESD of chest PA, lumbar spine
AP, skull AP/PA and skull LAT were higher than UK
DRL. In addition, mAs showed a high positive correlation
with ESD while weight, age and kVp were showed
a low correlation with ESD.
Conclusion: This study provided the median ESD in
Srinagarind hospital and already compared with national
DRL, international IAEA DRL, Japanese DRL and
UK DRL. When the median ESD was higher than national
and international DRL, technologist and team
member could investigate and determine the cause
of problem. The quality assurance program and efficiency
of X-ray machine firstly check to ensure the
good performance of the machine and radiation
output and then the protocol and exposure technique
were also revised. Further step, dose optimization is
required to reduce the patient dose and limit the
stochastic effect risk.
Keywords
Digital Radiography; Entrance Skin Dose; Diagnostic reference level