Water as a contrast medium: a re-evaluation using the multidetector-row computed tomography

Area of Science:

• Radiology and Medical Imaging
• Gastrointestinal Imaging
• Computed Tomography (CT)

Background:

• Oral water as an intraluminal negative contrast medium can enhance CT image quality by reducing artifacts.
• Previous limitations in water's clinical use were due to rapid bowel absorption, not aligning with older imaging speeds.
• Advances in multidetector-row CT (MDCT) necessitate re-evaluating water's efficacy as a contrast agent.

Purpose of the Study:

• To compare image quality, specifically luminal distention and clarity, between pancreas protocol CT (PPCT) using oral water and conventional positive oral contrast CT.
• To assess the effectiveness of water as a negative contrast agent in modern CT technology.

Main Methods:

• Retrospective review of 66 patients who underwent both PPCT with oral water and conventional oral contrast abdominal CT.
• Independent radiologist scoring of hollow viscus distention and mural detail using a Likert scale.
• Statistical analysis including Wilcoxon-signed rank test for image quality, Student's t test for radiation dose, and Spearman's correlation for interrater reliability.

Main Results:

• No significant difference in mean radiation dosage between the two protocols.
• PPCT with water demonstrated statistically significant improvements in clarity and distention in the stomach and duodenum compared to conventional contrast.
• Water provided better or equal bowel distention and clarity compared to routine barium contrast, supporting its efficacy with current CT technology.

Conclusions:

• Modern CT technology enables water to be an effective intraluminal negative contrast medium.
• Water offers comparable or superior image clarity and luminal distention in the stomach and duodenum versus traditional contrast agents.
• The findings support reconsidering the clinical application of water as a contrast agent in CT imaging.