Evaluation of the effects of food and fasting on signal intensities from the gut region in mice during magnetic particle imaging (MPI)

Gastrointestinal signals present a major challenge in magnetic particle imaging (MPI) because of their strong background interference. This study aimed to evaluate and compare the gut MPI signal in mice fed six commercially available diets in Australia, including Gordon’s Specialty Stock Feeds (normal and low iron), Specialty Feeds (normal and low iron), a Western diet, and Gubra-Amylin NASH (GAN diet). We also assessed the impact of 24 h fasting on gut signal reduction. Each diet group included three mice, and the gut signal intensity was monitored over seven days. The results indicated that the standard diet produced signal intensities approximately eight times greater than those of the low-iron diet from specialty feeds and over eleven times greater than those of the GAN or Western diets. Notably, switching to GAN or Western diets led to a tenfold reduction in the gut signal within 24 h, a decrease comparable to that achieved by fasting. These findings suggest that dietary modification—particularly the use of low-iron diets—can effectively minimize gastrointestinal signals in MPI, reducing background interference by up to 90%. This simple dietary adjustment offers a practical and noninvasive method for improving image clarity and experimental reliability in preclinical MPI studies.