Sea Moss (Eucheuma cottonii) Extract as a Natural X-ray Contrast Candidate: Experimental Evaluation of Image Quality, Physicochemical Behavior, and Sensory Acceptability

Synthetic radiographic contrast agents remain standard in diagnostic imaging but pose safety, cost, and acceptability concerns, which has renewed interest in bio-based alternatives.Seaweeds such as Eucheuma cottonii supply carrageenan and iodine and may offer a natural platform for contrast formulations.This experimental study evaluated three sea moss extract formulations and a commercial barium sulfate suspension as a reference.Prepared suspensions underwent in-vitro X-ray imaging under fixed exposure factors.Five radiologic technologists rated density, contrast, detail, and overall quality.Miscibility in water and alcohol and relative viscosity by gravitational flow were assessed.The most concentrated extract produced high image quality, whereas lower concentrations were rated low to moderate; barium sulfate achieved very high scores.The optimized extract showed complete miscibility in water, partial miscibility in alcohol, and the highest viscosity, consistent with a carrageenan-rich hydrocolloid.Results support E. cottonii extract as a promising candidate matrix for natural contrast development, subject to further optimization and safety testing.