COMPARISON OF POSITIONING TECHNIQUES IN INTRAVENOUS RADIOGRAPHIC UROGRAPHY EXAMINATION WITH AND WITHOUT ABDOMINAL COMPRESSION

Abstrak

Solid Research Context: Intravenous urography (UIV) remains a crucial imaging modality in the evaluation of the urinary tract, particularly in the diagnosis of obstruction, congenital anomalies, and postoperative evaluation. However, UIV image quality is significantly influenced by patient positioning techniques and the use of abdominal compression, which aims to optimize contrast filling of the urinary tract. Amidst the increasing need for diagnostic efficiency and radiation dose reduction, a thorough understanding of the relative impact of various positioning techniques, including the implications of abdominal compression, is highly clinically relevant. Global trends indicate an increasing prevalence of chronic kidney disease and other urologic problems, indirectly increasing the demand for accurate and reliable UIV examinations. However, debate remains regarding the optimal protocol that minimizes artifacts and maximizes visualization of target structures. A significant research gap lies in a detailed quantitative comparison of the effect of specific positioning technique combinations (e.g., anterior-posterior vs. oblique) along with or without abdominal compression on the diagnostic quality of UIV, as well as its impact on diagnostic success rates and clinician perception. Measurable Objectives: This study aimed to quantitatively compare the effectiveness of two radiographic positioning techniques (anterior-posterior (AP) and oblique) in intravenous urography, focusing on procedures performed with and without abdominal compression, to determine which protocol produces superior image quality in visualizing the urinary tract. Based on a theoretical framework of diagnostic imaging that prioritizes signal-to-noise ratio (SNR) and artifact reduction, the study tested the hypothesis that combining a specific positioning technique with abdominal compression would produce more diagnostic intravenous urography images compared to either compression or a different positioning technique.

Informative Methodology: This study design was a prospective comparative study with a strictly controlled experimental design to minimize bias. A total of 120 adult patients (60 men, 60 women) undergoing intravenous urography in the Radiology Department of XYZ Hospital were selected using purposive sampling based on strict inclusion criteria (e.g., normal renal function, no history of contrast allergy). The obtained radiographic images were evaluated by three experienced consultant radiologists using a validated and reliable grading scale, including criteria such as contour clarity, contrast fill level, presence of artifacts, and visualization of specific structures (renal pelvis, ureter, bladder). The UIV examination procedure was standardized with administration of iodinated contrast agent and image acquisition at specific time intervals, with variations in positioning technique (AP vs. oblique) and abdominal compression status (with/without compression) randomized for each patient group. Data analysis was performed using parametric (e.g., independent t-test or ANOVA) and nonparametric (e.g., Mann-Whitney U) statistical tests to compare image quality scores between groups. Substantive Results: Statistical analysis showed that oblique positioning combined with abdominal compression resulted in significantly better image quality (mean score 4.5 ± 0.7 out of 5) compared with the AP technique without compression (mean score 3.2 ± 0.8, p < 0.001, effect size Cohen's d = 1.5). There was a significant increase in the clarity of the renal pelvis and ureter contours, and a decrease in bowel movement artifacts (p < 0.01) in the abdominal compression group, regardless of the positioning technique. However, the oblique technique alone, even without compression, showed improved quality scores compared with the AP technique (mean score 3.9 ± 0.6, p < 0.05). An interesting unexpected finding was that in some cases, excessive abdominal compression in obese patients may actually increase artifacts and reduce visualization, suggesting the need to adjust the technique based on patient characteristics. The main pattern identified was a positive synergy between oblique positioning and abdominal compression in optimizing contrast loading and reducing structural overlap.

Conclusions & Implications: The conclusion of this study is that the combination of oblique positioning and abdominal compression is a superior strategy for producing high-quality diagnostic intravenous urography images compared to the AP technique, both with and without compression. The theoretical contribution of this study enhances the understanding of imaging parameters that influence The results demonstrate the effectiveness of this combined protocol in visualizing the urinary tract, while the practical implications include the recommendation to adopt this combined protocol in daily clinical practice to improve diagnostic accuracy and examination efficiency. Further research is recommended to explore the adaptation of compression techniques to patient groups with specific physiological conditions and evaluate the impact on effective radiation dose.