title: Measurement of oro-caecal transit time by magnetic resonance imaging.
abstract: OBJECTIVE
  To assess prospectively the agreement of orocaecal transit time (OCTT) measurements by lactulose hydrogen breath test (LHBT) and magnetic resonance imaging (MRI) in healthy subjects.
  
  
  METHODS
  Volunteers underwent abdominal 1.5-T MRI using axial and coronal single-shot fast-spin-echo T2-weighted sequences, having fasted and after lactulose ingestion (10 g/125 mL). Imaging and H2 excretion gas-chromatography were performed concurrently every 15 min up to 180 min. MR images were analyzed using semiautomatic segmentation to calculate small bowel gas volume (SBGV) and visually to detect bolus arrival in the caecum. Agreement between MRI- and LHBT-OCTT was assessed.
  
  
  RESULTS
  Twenty-eight subjects (17 men/11 women; mean age ± standard deviation 30 ± 8 years) were evaluated. Two H2 non-producers on LHBT were excluded. OCTT measured by MRI and LHBT was concordant in 18/26 (69 %) subjects (excellent agreement, k = 0.924). Median SBGV was 49.0 mL (interquartile interval 44.1 - 51.6 mL). In 8/26 (31 %) subjects, MRI showed that the lactulose bolus was in the terminal ileum and not the caecum when H2E increased on LHBT. Median OCTT measured by MRI was significantly longer than OCTT measured by LHBT [135 min (120 - 150 min) vs. 127.5 min (105 - 150 min); p = 0.008]. Above baseline levels, correlation between [H2] and SBGV was significant (r = 0.964; p < 0.001).
  
  
  CONCLUSIONS
  MRI provides valid measurements of OCTT and gas production in the small bowel.
  
  
  CONCLUSIONS
  • MRI is a valid technique to measure OCTT. • Excellent agreement between MRI and LHBT was found. • Measuring gas production using MRI may provide evidence of small bowel fermentation.
authors.affiliation: Division of Gastroenterology, Department of Surgical, Oncological and Gastroenterological Sciences, Padua, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Savarino
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Savarino
authors.forename: Mark
authors.initials: M
authors.lastname: Fox
authors.forename: Giovanni
authors.initials: G
authors.lastname: Di Leo
authors.forename: Manuele
authors.initials: M
authors.lastname: Furnari
authors.forename: Elisa
authors.initials: E
authors.lastname: Marabotto
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Gemignani
authors.forename: Luca
authors.initials: L
authors.lastname: Bruzzone
authors.forename: Alessandro
authors.initials: A
authors.lastname: Moscatelli
authors.forename: Chiara
authors.initials: C
authors.lastname: De Cassan
authors.forename: Francesco
authors.initials: F
authors.lastname: Sardanelli
authors.forename: Luca Maria
authors.initials: LM
authors.lastname: Sconfienza
mesh_terms: D000328:Adult; D001944:Breath Tests; D002432:Cecum / Q000502:physiology*; D005260:Female; D005772:Gastrointestinal Transit / Q000502:physiology*; D006801:Humans; D007421:Intestine, Small / Q000502:physiology*; D007792:Lactulose / Q000008:administration & dosage; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D007792:Lactulose