Radiological Society of North America 2005 Scientific Assembly and Annual Meeting

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Research Title: 
Real-time High-Resolution MR Imaging for the Assessment of Gastric Motility Disorders
Authors: 
Waleed Ajaj
Authors: 
Susanne Charlotte
Authors: 
Christiane Astrid Kuehle
Authors: 
Thomas C. Lauenstein
Authors: 
Jorg Barkhausen
Authors: 
Michael Nuefer
Date: 
Thu, 2005-12-01
Research Abstract: 

Functional pathologies of the GI tract are highly prevalent, but all available tests to assess motor function are either invasive, expose the patient to radiation or are inaccurate. Aim of this study was to determine the practicability of a real-time TrueFISP sequence for the assessment of gastric motion in patients with gastric motility disorders and compare the results with reference values obtained in a healthy volunteer group.
METHOD AND MATERIALS
Thirty subjects were included: Ten healthy volunteers (reference group A). ten patients with gastroparesis (group B) and ten patients with functional pylorospasm or peptic pyloric stenosis (group C). 400 ml of a high caloric, liquid nutrient was ingested after a six hour fast. Subjects were imaged in the supine position on a 1.5T scanner (Magnetom , Siemens Medical Systems/Germany) in five-minute intervals up toâSonata 30 minutes following the ingestion. The acquisition time for the real-time scan amounted to 20 sec. The acquisition plane was chosen interactively to be parallel to the axis of the gastric antrum. For each data set a motility index was calculated. Therefore, the minimal diameter of the antrum lumen parallel to the scan axis was multiplied with the distance that one peristaltic wave had passed within 20 sec. Indices of each group were compared using a McNemar test.
RESULTS
Ingestion of the liquid nutrient led to a homogeneously high signal on the real-time 2D TrueFISP data sets. This allows a reliable delineation of the gastric lumen and gastric wall. For the examination at 15 minutes average values of the motility index within the volunteer group amounted to 2.5 cm2/sec (SD = +/- 0.29). For patients with functional pylorospasm and peptic pyloric stenosis, however, the mean index at the same acquisition time point was 9 mm2/s (range 7-16 mm2/s). In opposite, patients with gastroparesis were found to have a mean motility index of 1.5 mm2/s (range 1.2-1.9 mm2/s). Differences were statistically significant (p<.05).
CONCLUSION
Gastric motility can be assessed by means of real-time MRI. Patients with decreased gastric motion can be reliably distinguished from patients with increased gastric motility.