title: Assessment of Crohn's disease activity by Doppler sonography of the superior mesenteric artery, clinical evaluation and the Crohn's disease activity index: a prospective study.
abstract: OBJECTIVE
  Recent data have shown that superior mesenteric artery (SMA) flow rates are significantly increased in active Crohn's disease, suggesting that SMA flow may be a useful, non-invasive index of disease activity. The aim of this prospective study was to evaluate the use of SMA Doppler sonography as an indicator of Crohn's disease activity and to compare with clinical evaluation and the Crohn's disease activity index (CDAI).
  
  
  METHODS
  Patients with active Crohn's (n = 19), inactive Crohn's (n = 17) and control subjects (n = 17) were evaluated. Categorization of disease activity was based on a reference standard. CDAI scores were also calculated independently. The SMA flow parameters evaluated were resistive index, pulsatility index, end diastolic velocity, peak systolic velocity, time averaged maximum velocity, cross-sectional area and maximum flow volume.
  
  
  RESULTS
  Using a three-group ANOVA for each of peak systolic velocity (PSV) (P = 0.01), end-diastolic velocity (EDV) (P = 0.04), pulsatility index (PI) (P = 0.003), time-averaged maximum velocity (TAMV) (P = 0.05), and maximum flow volume (TAMV.CSA) (P = 0.01), there was a significant effect of group. Using post-hoc tests, only EDV (P = 0.01), TAMV (P = 0.02) and TAMV.CSA (P = 0.003) were significantly different between active and inactive Crohn's disease, though with considerable overlap of values for EDV and TAMV. The mean CDAI scores were significantly different between patients with active Crohn's (287) and inactive Crohn's (71) (P = 0.0001) and correlated well with the reference standard.
  
  
  CONCLUSIONS
  Only three of several parameters previously described as allowing Crohn's disease activity assessment actually did so in our study. However, for two of these parameters (EDV, TAMV), there was overlap between the measurements in the active and inactive groups, thus limiting the ability to discriminate disease activity in practice. The degree of overlap for maximum flow volume (TAMV.CSA) between active and inactive disease was considerably less and this parameter may be more discriminatory of disease activity. On the other hand, we found CDAI scores to be accurate in disease categorization. We agree that there appear to be hyperdynamic changes in active Crohn's disease but suggest that Doppler ultrasound assessment does not reliably assess disease activity in routine clinical practice.
authors.affiliation: Department of Gastroenterology, Beaumont Hospital, Dublin, Ireland. mfbyrne@rcsi.ie
authors.forename: M F
authors.initials: MF
authors.lastname: Byrne
authors.forename: M A
authors.initials: MA
authors.lastname: Farrell
authors.forename: S
authors.initials: S
authors.lastname: Abass
authors.forename: A
authors.initials: A
authors.lastname: Fitzgerald
authors.forename: J C
authors.initials: JC
authors.lastname: Varghese
authors.forename: F
authors.initials: F
authors.lastname: Thornton
authors.forename: F E
authors.initials: FE
authors.lastname: Murray
authors.forename: M J
authors.initials: MJ
authors.lastname: Lee
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D003424:Crohn Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D017538:Mesenteric Artery, Superior / Q000000981:diagnostic imaging* / Q000502:physiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012039:Regional Blood Flow; D012720:Severity of Illness Index; D018608:Ultrasonography, Doppler / Q000379:methods