Abstract
Computed Tomography (CT) is generally accepted as a valuable diagnostic imaging modality producing high-quality, detailed cross-sectional imaging. However, CT is the primary source of radiation exposure in medical imaging and is associated with an increased risk of biological challenges. The main source of radiation exposure to internal organs outside the imaging area primarily results from X-rays scattering within the body. There is a scarcity of research devoted to investigating internal scatter and the use of lead rubber surface shielding in CT. Therefore, the study aimed to investigate the impact of lead rubber surface shielding on internal scatter in an anthropomorphic adult RANDO phantom undergoing a CT of the brain, chest, abdomen, and pelvis.
This quantitative experimental study was performed at Nelson Mandela’s Children’s Hospital (NMCH) using the 128-channel multidetector-row General Electric (GE) Optima CT660 CT scanner. An anthropomorphic RANDO phantom equivalent to a 70-kilogram (kg) adult, designed slots for thermoluminescent dosimeters’ (TLDs) placement, was used and underwent CT imaging. The brain, chest, abdomen, and pelvis were imaged with and without lead rubber surface shielding, while all other variables remained constant. The TLD measurements were recorded and statistically analysed.
The experiment demonstrated that the inverse square law applies to internal scatter in CT scans. The areas far from the primary exposure area recorded lower internal scatter levels than the areas within the X-ray beam. The results of the CT examination of the brain, chest, abdomen and pelvis indicated minimal changes to the internal scatter regardless of lead rubber shielding.