title: Functional brain imaging in irritable bowel syndrome with rectal balloon-distention by using fMRI.
abstract: OBJECTIVE
  Irritable bowel syndrome (IBS) is characterized by abdominal pain and changes in stool habits. Visceral hypersensitivity is a key factor in the pathophysiology of IBS. The aim of this study was to examine the effect of rectal balloon-distention stimulus by blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) in visceral pain center and to compare the distribution, extent, and intensity of activated areas between IBS patients and normal controls.
  
  
  METHODS
  Twenty-six patients with IBS and eleven normal controls were tested for rectal sensation, and the subjective pain intensity at 90 ml and 120 ml rectal balloon-distention was reported by using Visual Analogue Scale. Then, BOLD-fMRI was performed at 30 ml, 60 ml, 90 ml, and 120 ml rectal balloon-distention in all subjects.
  
  
  RESULTS
  Rectal distention stimulation increased the activity of anterior cingulate cortex (35/37), insular cortex (37/37), prefrontal cortex (37/37), and thalamus (35/37) in most cases. At 120 ml of rectal balloon-distention, the activation area and percentage change in MR signal intensity of the regions of interest (ROI) at IC, PFC, and THAL were significantly greater in patients with IBS than that in controls. Score of pain sensation at 90 ml and 120 ml rectal balloon-distention was significantly higher in patients with IBS than that in controls.
  
  
  CONCLUSIONS
  Using fMRI, some patients with IBS can be detected having visceral hypersensitivity in response to painful rectal balloon-distention. fMRI is an objective brain imaging technique to measure the change in regional cerebral activation more precisely. In this study, IC and PFC of the IBS patients were the major loci of the CNS processing of visceral perception.
authors.affiliation: Department of Gastroenterology, Ruijin Hospital, Shanghai Second Medical University, Shanghai 200025, China. yyz28@hotmail.com
authors.forename: Yao-Zong
authors.initials: YZ
authors.lastname: Yuan
authors.forename: Ran-Jun
authors.initials: RJ
authors.lastname: Tao
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.forename: Ke-Min
authors.initials: KM
authors.lastname: Chen
authors.forename: Fei
authors.initials: F
authors.lastname: Miao
authors.forename: Zhong-Wei
authors.initials: ZW
authors.lastname: Zhang
authors.forename: Jia-Yu
authors.initials: JY
authors.lastname: Xu
mesh_terms: D000328:Adult; D002404:Catheterization; D002560:Cerebrovascular Circulation; D003109:Colonic Diseases, Functional / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D012007:Rectum / Q000503:physiopathology*
chemical_list: D010100:Oxygen