An investigation of scatter removal techniques in paediatric cardiac catheterisation imaging: effects upon radiation dose, image quality DNA integrity and cancer risk

Abstract

This thesis investigated the potential for radiation dose reduction in paediatric cardiaccatheterisation (PCC). A systematic literature review was performed to assess theradiation doses reportedly received by patients undergoing PCC. A wide variation inradiation dose was reported. Children are receiving radiation doses equivalent toreceiving >1000 chest radiographs. An in vitro investigation to assess the effects of thepresence of iodinated contrast media (ICM) during ionising radiation exposure relevantto PCC was performed. It was demonstrated that iodine caused a significant increase in deoxyribonucleic acid (DNA) double-strand breaks (DSBs). An in vitro tissueequivalent phantom study assessed the need to use an anti-scatter (AS) grid in PCC.Large variations in radiation dose reductions were observed with greater signal-to-noise ratio (SNR) in the mediastinum (17 - 67%) by removing the AS grid or by using a 15cm air-gap (AG) between the phantom and X-ray detector. Ethical approval wasobtained for a randomised control trial (RCT). PCC was performed on 70 childrenusing either (1) the current imaging protocol (use of the AS grid), (2) no AS grid, or (3)no AS grid and a 15 cm AG. The results demonstrated that by removing the AS grid,the average radiation dose was reduced by 53%. The number of DNA DSBs wasreduced by 20 - 30% and estimated cancer mortality risk by 18 - 45%. Proceduresperformed without the use of the AS grid were judged to have sufficient clinical imagequality and diagnostic efficacy. It was demonstrated that participants receiving ICMhad 19% more DNA DSBs. This thesis has added to the body of knowledge and willassist clinicians making evidence-based decisions. This work may contribute tolowering radiation dose and biological detriment to children with congenital heartdisease (CHD).

Date of Award	Feb 2016
Original language	English
Supervisor	Ciara Hughes (Supervisor) & Sonyia McFadden (Supervisor)