New Oral Contrast Agent Shows Promise for Improved Bowel Imaging in Phase 2 Study

A novel oral contrast agent is demonstrating significant advantages over existing options, according to early results from a pilot phase 2 feasibility study. The imaging compound, known as dark borosilicate oral contrast media, offers clearer visualization of bowel structures and disease processes in patients undergoing CT scans, outperforming traditional agents in key diagnostic areas.

Developed by California-based imaging company Nextrast, the dark contrast agent is designed to enhance diagnostic accuracy by improving contrast between the bowel wall and lumen. The ongoing study involves collaborators from the Mayo Clinic, University of California San Francisco, University of Washington School of Medicine, and Nextrast.

"We carefully designed this new class of oral contrast agent to overcome many of the diagnostic shortcomings of existing contrast agents for a broad range of diseases,” said Benjamin Yeh, MD, radiologist at UCSF and co-founder of Nextrast. “The clinical phase 2 results confirm that our dark agent can reveal previously impossible-to-detect findings, including very small bowel tumors and subtle inflammatory conditions that are often missed with conventional agents at CT."

The study involves two groups of patients: those with known or suspected inflammatory bowel disease and those with suspected peritoneal carcinomatosis. Each patient underwent a CT scan using the new contrast agent, with their results compared to prior imaging completed using standard oral contrast materials.

Researchers reported significantly improved bowel wall visualization, lumen distention, and total distended bowel length when using the new agent, with gains observed from the stomach through the ileum. These improvements led to additional imaging findings in 22% of study participants. In addition, radiologists who reviewed the scans reported a preference for images acquired with the new agent over those from prior exams using traditional contrast.

"CT scans performed with the new agent will likely do a better job of displaying pathologies in the stomach and proximal small bowel, areas where CT with traditional oral contrast performs poorly," said lead author Joel Fletcher, MD, medical director of the Mayo Clinic CT Clinical Innovation Center. “Pathologies within the lumen will be better displayed because the lumen is more distended, and the brightness of the pathologies on the CT images will be increased, making them more conspicuous.”

Although the early results are encouraging, the researchers emphasized the need for further evaluation in larger and more diverse patient populations. They anticipate that the agent’s superior performance could help improve diagnostic accuracy for a wide range of gastrointestinal conditions, particularly those that have been challenging to detect with existing contrast media.