Impact of Dose Optimization Protocols on Pediatric Chest Radiography Outcomes

Thesis Abstract

The study investigates how dose optimization protocols influence the diagnostic quality, radiation exposure, and overall patient safety outcomes in pediatric chest radiography within two urban tertiary hospitals over a 12-month period. The problem addressed is the persistent tension between minimizing ionizing radiation dose and maintaining sufficient image quality for accurate pediatric diagnosis, compounded by variability in protocol adherence and equipment capabilities. The aim is to evaluate the effectiveness of standardized dose optimization protocols in improving image quality while reducing effective dose in children aged 0–12 years. Specific objectives are to (1) quantify changes in entrance surface dose (ESD) and computed tomography dose index (CTDIvol)-equivalent metrics before and after protocol implementation, (2) assess radiographic image quality using a standardized scoring system adapted from the European Guidelines on Radiographic Quality, (3) determine adherence levels to the optimization protocols among radiographers, (4) identify radiographic technique factors associated with optimal doses, and (5) examine patient-level outcomes such as repeat radiographs and need for retakes. The theoretical framework integrates the Health Belief Model to understand radiographer motivation and the Theory of Planned Behavior to account for practice adherence, complemented by diffusion of innovations theory to explain protocol uptake. The study adopts an explanatory mixed-methods design, with a quantitative phase followed by a qualitative phase to enrich interpretation. The population includes pediatric radiography departments across two tertiary hospitals, and the sample comprises 1,200 chest radiographs from children aged 0–12 years collected pre- and post-implementation, along with 20 focus group discussions and 30 in-depth interviews with radiographers, radiologists, and supervising physicians. Data collection instruments include calibrated dosimetry records, a validated image quality scoring rubric, standardized radiographic technique checklists, and semi-structured interview guides. Instrument validity is established through expert panel reviews and pilot testing, with reliability assessed via intra-class correlation for image quality scores (ICC > 0.80) and Cronbach’s alpha for survey items (? > 0.7). Quantitative analysis employs descriptive statistics, paired t-tests for dose comparisons, repeated-measures ANOVA to examine temporal effects across age groups, and multivariate linear regression to identify technique factors predicting image quality while controlling for patient age and weight. Dose optimization effectiveness is further analyzed using hierarchical linear modeling to account for clustering by radiology unit. For qualitative data, thematic analysis follows a six-step approach with coding reliability checks, triangulating findings with quantitative results. Ethical considerations include informed consent waivers for retrospective imaging data, de-identification procedures, and approval from institutional review boards. Expected findings anticipate a statistically significant reduction in mean ESD and CTDIvol-equivalents post-implementation, without a clinically meaningful decline in image quality scores (mean difference within 0.5 points on a 5-point scale), and a reduction in repeat radiographs by at least 15%. It is also anticipated that high-adherence units will demonstrate greater dose reductions and stable or improved diagnostic quality, with qualitative insights indicating perceived barriers and drivers of protocol adherence, such as training adequacy, equipment firmware updates, and workflow integration. The study aims to contribute to knowledge by providing robust, context-specific evidence on the real-world effectiveness of dose optimization protocols in pediatric radiography, informing guidelines for pediatric imaging and offering a model for multi-site adoption. The anticipated conclusion is that carefully designed dose optimization protocols, coupled with targeted training and ongoing monitoring, can achieve substantial dose reductions in pediatric chest radiography without compromising diagnostic accuracy, while highlighting the critical role of organizational culture and technology support. Recommendations include implementing mandatory dose-optimization checklists, routine dose auditing with feedback loops, continuous professional development for radiographers, and integrating dose metrics into electronic health record dashboards to sustain improvements. The study also suggests further research into protocol customization for infants and children with chronic cardiopulmonary conditions and the cost-effectiveness of optimization strategies in resource-constrained settings.