New Oral Contrast Agent Enhances CT Detection of Bowel Disease

A novel oral contrast agent for CT imaging significantly improves visualization of bowel anatomy and disease, according to a pilot Phase 2 study conducted by researchers from Mayo Clinic, the University of Washington, the University of California, San Francisco, and Nextrast Inc.

The agent, described as a “dark” borosilicate oral contrast, is ingested prior to imaging and is designed to address limitations of conventional water- or iodine-based agents. In a study of 32 patients, CT scans performed with the new agent demonstrated superior detection of abdominal pathology, including inflammatory bowel disease (IBD) and cancer.

“The new oral contrast agent… helps detect pathologies within and outside of the bowel wall in ways current imaging agents do not,” said lead author Joel Fletcher, MD, medical director of the Mayo Clinic CT Clinical Innovation Center.

Researchers reported that evaluators identified clinically relevant findings in seven patients that were not seen using standard contrast agents. Improved bowel distension and enhanced contrast between tissue and lumen contributed to better visualization, particularly in the stomach and proximal small bowel.

“CT scans performed with the new agent will likely do a better job of displaying pathologies… where CT with traditional oral contrast performs poorly,” Fletcher said, noting that increased luminal distension and lesion brightness make abnormalities more conspicuous.

Benjamin Yeh, MD, radiologist at UCSF and co-founder of Nextrast, emphasized the agent’s broader diagnostic potential. “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,” he said.

First author Achille Mileto, MD, of the University of Washington, added that the agent “has the potential to improve the assessment of numerous pathologies, including the detection of cancer and inflammatory disorders.”

While the findings are preliminary, investigators say the results support further evaluation in larger patient populations.