Automated extraction of anorectal pressures from high-resolution manometry reports

Mohamed ElWazir, Misha Gautam, Rahul Mishra, Nicholas R. Oblizajek, John W. Blackett, Adil E. Bharucha

Research output: Contribution to journalArticlepeer-review


Background: During high-resolution anorectal manometry (HR_ARM), the raw data are converted into software-derived summary variables (e.g., rectoanal gradient during evacuation) that capture only a snapshot of the data collected during HR_ARM and are less useful than newer indices, which are also derived from the raw data, for diagnosing defecatory disorders (DD). However, it is cumbersome and time-consuming to extract raw data from the program and calculate such indices. This study aimed to devise a user-friendly approach to extract anorectal pressures measured with HR_ARM. Methods: Anorectal pressures at rest, during anal squeeze, and evacuation were measured with HR_ARM in 180 women, among whom 60 each were healthy, had DD, or fecal incontinence. A reverse engineering approach extracted pressure values from color images in HR_ARM reports. The summary variables generated by the software and a reverse engineering approach were compared with Lin's concordance correlation coefficient (CCC), paired t-tests, and Bland–Altman's tests. Results: Anorectal pressures summarized by the software and a reverse engineering method were highly concordant for anal resting (CCC [95% CI], 0.98 [0.97, 0.99]) and squeeze pressures (0.99 [0.99, 0.99) and the rectoanal gradient during evacuation with an empty (0.98 [0.97, 0.98]) and a filled balloon (0.99 [0.99, 0.99]). For most variables, the paired t and Bland–Altman comparisons were not significant. Conclusions: Anorectal pressures can be accurately determined from pressure topography images in HR_ARM reports. In future, this reverse engineering approach can be harnessed to compile large HR_ARM datasets across centers and to uncover newer, potentially more useful summary rectoanal pressure variables.

Original languageEnglish (US)
Article numbere14411
JournalNeurogastroenterology and Motility
Issue number11
StatePublished - Nov 2022


  • International anorectal physiology working group
  • anal weakness
  • chronic constipation
  • diagnostic accuracy
  • pelvic floor dysfunction

ASJC Scopus subject areas

  • Physiology
  • Endocrine and Autonomic Systems
  • Gastroenterology


Dive into the research topics of 'Automated extraction of anorectal pressures from high-resolution manometry reports'. Together they form a unique fingerprint.

Cite this