Page 138 - Hospital Authority Convention 2018

Service Enhancement Presentations
HOSPITAL AUTHORITY CONVENTION 2018

F4.4 Clinical Safety and Quality Services II 16:15 Room 421

Are We Imaging Gently Enough? A Clinical Audit on Paediatric Digital Chest Radiograph Dosages
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Fung KFK , Chan TYE , Yeung TW , Lau HY , Wong YC 2
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Department of Diagnostic and Interventional Radiology, Kwong Wah Hospital, Department of Radiology, Tuen Mun Hospital,
Hong Kong
Introduction
Radiation protection is an important issue in paediatric radiology, as children are more susceptible to deleterious radiation-
induced effect than adult. Digital chest radiography, despite its relatively low radiation dose, is one of the most frequent
examinations performed in the paediatric patients. Image enhancement through post processing may mask improper
collimation or exposure factors. It is therefore important to ensure radiation dose delivered to our paediatric patients is as low
as reasonably achievable through clinical audit.

Objectives
To audit the dosage of digital chest radiography performed in paediatric patients in Tuen Mun Hospital.

Methodology
Monday, 7 May 2018 as no local DRL is available. All patients from age 0 to 15 years with CXR taken at main department of TMH were included in
Phase one audit was performed prospectively from January to March 2017, collecting dose-area products (DAPs) and
identifying potential factors leading to excessive radiation dosages. Phase two audit followed in July to September 2017 after
changes have been implemented. European diagnostic reference level (EDRL) for paediatric imaging was used as standard

this audit. The patients were assigned to nominal age group 0, 1, 5, 10 and 15 years. Portable CXR, CXR taken for line/tube
placement and whole body radiograph were excluded. Image quality was assessed using European Guidelines on Quality
Criteria for Diagnostic Radiographic Images in Paediatrics by two independent paediatric radiologists. Rejection analysis was
also performed.
Results
63 and 93 radiographs were assessed in phase one and two audits respectively. Excessive radiation dosages were identified
in age groups 0 and 1 in phase one audit. Key contributors to high radiation dose include high rate of anti-scatter grid
use, inadequate collimation, and frequent automatic exposure control use in small patients. Standardised paediatric CXR
protocol addressing these issues was established after phase one audit. In phase two audit, median doses in all age groups
were below EDRL. There was also good adherence to the newly established protocol. All CXRs in phase two audit show
acceptable diagnostic quality. Rejection rate was 6.3% in phase one and 5.4% in phase two audit.

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