HISTOLOGICAL CORRELATES TO PIG GASTROINTESTINAL WALL LAYERS IMAGED IN-VITRO WITH THE MAGNETIC-RESONANCE ENDOSCOPE

Background & Aims: The magnetic resonance endoscope consists of a nonf erromagnetic endoscope with a receiver coil incorporated into its tip. The aim of this study was to define the anatomic correlates of the ga strointestinal wall layers imaged in vitro with the magnetic resonance endoscope. Methods: Twenty-two tissue specimens from various segments of the porcine gastrointestinal tract were imaged with the magnetic r esonance endoscope using up to four different scanning sequences. Cyan oacrylate, serving as a marker, was randomly injected into the tissue strips before imaging. Histological sections were then compared with t he magnetic resonance images. Results: T1-weighted spin echo sequences yielded the highest image quality and typically showed three wall lay ers that corresponded to distinct histological layers. The mucosa show ed high signal intensity, the submucosa low signal intensity, and the muscularis propria an intermediate signal intensity. In the esophagus and rectum, the muscularis propria could be visualized as separate cir cular and longitudinal layers, Conclusions: In vitro imaging with the magnetic resonance endoscope shows three to five wall layers of the po rcine gastrointestinal tract depending on the segment scanned. This de gree of gut wall resolution suggests that endoscopic magnetic resonanc e imaging may have potential for local staging of gastrointestinal tum ors.