title: Comparison of manual and semiautomated techniques for analyzing gastric volumes with MRI in humans.
abstract: Gastric emptying, accommodation, and motility can be quantified with magnetic resonance imaging (MRI). The first step in image analysis entails segmenting the stomach from surrounding structures, usually by a time-consuming manual process. We have developed a semiautomated process to segment and measure gastric volumes with MRI. Gastric images were acquired with a three-dimensional gradient echo MRI sequence at 5, 10, 20, and 30 min after ingestion of a liquid nutrient (Ensure, 296 ml) labeled with gadolinium in 20 healthy volunteers and 29 patients with dyspeptic symptoms. The agreement between gastric volumes measured by manual segmentation and our new semiautomated algorithm was assessed with Lin's concordance correlation coefficient (CCC) and the Bland Altman test. At 5 min after a meal, food volumes measured by manual (352 ± 4 ml) and semiautomated (346 ± 4 ml) techniques were correlated {CCC[95% confidence interval (CI)] 0.70 (0.52, 0.81)}; air volumes measured by manual (88 ± 6 ml) and semiautomated (84 ± 6 ml) techniques were also correlated [CCC (95% CI) 0.89 (0.82, 0.94)]. Findings were similar at subsequent time points. The Bland Altman test was not significant. The time required for semiautomated segmentation ranged from an average of 204 s for the 5-min images to 233 s for the 20-min images. These times were appreciably smaller than the typical times of many tens of minutes, even hours, required for manual segmentation. To conclude, a semiautomated process can measure gastric food and air volume using MRI with comparable accuracy and far better efficiency than a manual process.
authors.affiliation: Division of Gastroenterology and Hepatology, Clinical Enteric Neuroscience Translational and Epidemiological Research Program, College of Medicine, Mayo Clinic, Rochester, Minnesota; bharucha.adil@mayo.edu.
authors.forename: Adil E
authors.initials: AE
authors.lastname: Bharucha
authors.affiliation: Biomedical Imaging Resource, College of Medicine, Mayo Clinic, Rochester, Minnesota;
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Karwoski
authors.affiliation: Department of Radiology, College of Medicine, Mayo Clinic, Rochester, Minnesota;
authors.forename: Jeff
authors.initials: J
authors.lastname: Fidler
authors.affiliation: Biomedical Imaging Resource, College of Medicine, Mayo Clinic, Rochester, Minnesota;
authors.forename: David R
authors.initials: DR
authors.lastname: Holmes
authors.affiliation: Biomedical Imaging Resource, College of Medicine, Mayo Clinic, Rochester, Minnesota;
authors.forename: Richard A
authors.initials: RA
authors.lastname: Robb
authors.affiliation: MR Research Laboratory, College of Medicine, Mayo Clinic, Rochester, Minnesota; and.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Riederer
authors.affiliation: Division of Biostatistics, College of Medicine, Mayo Clinic, Rochester, Minnesota.
authors.forename: Alan R
authors.initials: AR
authors.lastname: Zinsmeister
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004415:Dyspepsia / Q000175:diagnosis / Q000503:physiopathology; D001330:Electronic Data Processing; D005260:Female; D005682:Gadolinium; D005746:Gastric Emptying; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged
chemical_list: D005682:Gadolinium
keywords: emptying; magnetic resonance imaging; motility