Abstract
Background and Study Aims: The principle of endoscopic ultrasonography - introducing the transducer of an external imaging method, such as ultrasonography, in combination with an endoscope into the gastrointestinal tract for higher-resolution imaging - has also been applied to magnetic resonance imaging (MRI). We report here on our preliminary experience with a new method of endoscopic MRI in the upper gastrointestinal tract.
Patients and Methods: Endoscopic MRI was performed in 32 patients with esophageal (n = 8) or gastric diseases (n = 24), mostly tumors (n = 26). Most cancers were at an advanced stage (T3/T4). A prototype MRI endoscope connected to a 1.5 tesla MRI scanner was used. The accuracy of endoscopic MRI in visualizing and staging gastrointestinal lesions was assessed.
Results: The normal gastrointestinal wall consisted of three layers, and tumors were visualized as having a low signal intensity on both T1- and T2-weighted sequences. Destruction of the wall layers was found to be characteristic of malignancy. Sufficient images were obtained in seven of eight esophageal cases (88 %), but in only 14 of 24 gastric cases (58 %). In patients in whom adequate visualization was achieved, the endoscopic MRI results of local and regional staging were consistent with surgical, histopathological, CT and/or EUS results in all six esophageal cancer cases and in 89 % (T stage) and 56 % (N stage) of the nine patients with gastric cancer.
Conclusions: These preliminary results of endoscopic MRI are the first to be reported in the English literature. They show the potential of the method for local and regional staging, three-dimensional visualization of lesions being a potential advantage. Further technical improvements are expected.
