In which of these radiological examinations ionizing radiation is used?Question 33Select one:Digital subtraction angiographyUltrasoundMagnetic resonance imaging

Which of the following is a contrast X-ray technique?*magnetoencephalographyangiographystructural magnetic resonance imagingpositron emission tomographyfunctional MRI

Which radiological examination plays leading role in the differential diagnosis of peripheral lung cancer and benign tumor/structure?Question 20Select one:X-raysComputed tomographyMagnetic resonance imaging

Pediatric radiation exposure during medical imaging procedures has been a topic of increasing concern due to the potential long-term health implications associated with ionizing radiation. Previous studies have highlighted the heightened sensitivity of pediatric patients to radiation due to their developing tissues and longer life expectancy, necessitating a critical evaluation of radiation doses in pediatric imaging procedures (Sabarudin & Sun, 2013; BEIR VII Phase 2, 2006).In the context of computed tomography angiography (CTA), several studies have emphasized the need for optimizing imaging protocols to minimize radiation exposure while maintaining diagnostic quality. For instance, research by Xu and Zhang (2010) demonstrated the importance of dose optimization measures in reducing radiation exposure during CTA procedures. Similarly, Westra et al. (2014) highlighted the significance of entrance skin dose reduction in pediatric CT examinations.Furthermore, the American College of Radiology (ACR) has provided guidelines for quality control and radiation safety in computed tomography, emphasizing the ALARA principle and the use of protective shielding to minimize radiation exposure (ACR, 2017). These guidelines serve as a benchmark for evaluating the adherence to radiation safety measures in pediatric CTA procedures.Studies by Ali et al. (2019) and Hollingsworth et al. (2007) have provided valuable insights into radiation dose reduction initiatives and effective strategies for minimizing radiation exposure in cardiac CT and other imaging modalities. These initiatives underscore the importance of continuous improvement in imaging protocols to ensure patient safety.In summary, the existing literature underscores the critical need for optimizing imaging protocols, standardizing radiation doses, and adhering to radiation safety measures to minimize pediatric radiation exposure during CTA procedures. This literature review provides a foundation for the current study, which aims to comprehensively evaluate pediatric radiation exposure and imaging protocols in the context of CTA procedures.

X-rays are used in hospitals for computed tomography (CT) scans. (i) State one other medical use for X-rays. ______________________________________________________________ ______________________________________________________________(1) (ii) State a property of X-rays that makes them suitable for your answer in part (d)(i). ______________________________________________________________ ______________________________________________________________(1)

Tomography is imaging by sections. By aquiring multiple 2-D images from multiple , a 3-D image may be reconstructed with the aid of a tomographic reconstruction applied by a computer. The device used to produce the images is called a tomograph, while the image produced is a tomogram. Several different tomographic methods are used in modern medicine for purposes. Of particular interest to us are techniques which use radionuclides. In SPECT ( photon computed tomography), the patient is injected with a that decays by gamma-ray emission. These gamma rays are detected by a camera, forming an image of the distribution of the in the body of the patient. Another tomographic method that uses radionuclides is PET ( emission ). In this method, the radionuclide which is injected decays by (positive beta-particle) emission. It does not take long for the positron to collide with an , anihiliating each other, producing two that travel off in (generally) opposite directions. These of gamma-rays are then detected by the PET scanner.