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Endosonographic Anatomy of the Normal Anal Canal Compared with Endocoil Magnetic Resonance Imaging

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  • Published:
Diseases of the Colon & Rectum

Abstract

PURPOSE: This study was designed to clarify the sonographic anatomy of the normal anal canal by comparison with endoanal magnetic resonance imaging, to determine agreement between these imaging modalities and interobserver error in measuring layer thickness. METHODS: Three-dimensional endosonographic and endocoil magnetic resonance images of the anal canal were obtained in four males and five nulliparous females aged 22 to 34 years. Images were analyzed at similar levels throughout the canal using a graphics-overlay technique to compare sonographic with magnetic resonance images. Measurements were taken at one level for agreement analysis between modalities and for interobserver variability in the measurement of the thickness of the main anal canal layers. RESULTS: The muscularis submucosae ani, muscle bundles in the longitudinal muscle layer, and puboanalis were identified on sonography. The outer border of the external sphincter was demarcated by an interface reflection with ischioanal fat. Clarification of the external sphincter anatomy allowed excellent correlation (Ri = 0.96) for the assessment of thickness. There was excellent correlation for the interobserver measurement of the external and internal sphincters and the submucosal width on endosonography, but there was poor correlation for the longitudinal muscle (0.12). CONCLUSION: The overlay technique has improved endosonographic interpretation, and measurement of external sphincter thickness has been validated both by comparison with magnetic resonance and on interobserver agreement.

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References

  1. AH Sultan RJ Nicholls MA Kamm CN Hudson J Beynon CI Bartram (1993) ArticleTitleAnal endosonography and correlation with in vitro and in vivo anatomy Br J Surg 80 508–511

    Google Scholar 

  2. NM deSouza R Puni A Zbar DJ Gilderdale GA Coutts T Krausz (1996) ArticleTitleMR imaging of the anal sphincter in multiparous women using an endoanal coil AJR Am J Roentgenol 167 1465–1471

    Google Scholar 

  3. SM Hussain J Stoker AW Zwamborn et al. (1996) ArticleTitleEndoanal MRI of the anal sphincter complex J Anat 1893 677–682

    Google Scholar 

  4. UM Peschers JO DeLancey H Fritsch LE Quint MR Prince (1997) ArticleTitleCross-sectional imaging anatomy of the anal sphincters Obstet Gynecol 90 839–844

    Google Scholar 

  5. BE Van Beers A Kartheuser MA Delos et al. (1996) ArticleTitleMRI of the anal canal Magn Reson Imaging 14 151–156

    Google Scholar 

  6. E Rociu J Stoker JW Briel WR Schouten JS Lameris (1997) ArticleTitleEndoanal MR imaging evaluation of sphincter atrophy [abstract] Radiology 205 453–156

    Google Scholar 

  7. NM deSouza R Puni WA Kmiot CI Bartram AS Hall GM Bydder (1995) ArticleTitleMRI of the anal sphincter J Comput Assist Tomogr 19 745–751

    Google Scholar 

  8. DM Gold CI Bartram S Halligan KN Humphries MA Kamm WA Kmiot (1999) ArticleTitleThree-dimensional endoanal sonography in assessing anal canal injury Br J Surg 86 365–370

    Google Scholar 

  9. MJ Bland DG Altman (1986) ArticleTitleStatistical methods for assessing agreement between two methods of clinical measurement Lancet 1 307–310

    Google Scholar 

  10. PJ Lunniss RK Phillips (1992) ArticleTitleAnatomy and function of the anal longitudinal muscle Br J Surg 79 882–884

    Google Scholar 

  11. JC Golicher AG Leacock JJ Brossy (1955) ArticleTitleThe surgical anatomy of the anal canal Br J Surg 43 51–61

    Google Scholar 

  12. RV Gorsch (1960) ArticleTitleThe sigmoid, rectum, and anal canal. Relations, attachments and pelvic spaces Clin Symp 12 35–61

    Google Scholar 

  13. MB Kimmey RW Martin RC Haggitt KY Wang DW Franklin FE Silverstein (1989) ArticleTitleHistologic correlates of gastrointestinal ultrasound images Gastroenterology 9621 433–441

    Google Scholar 

  14. P Enck T Heyer B Gantke et al. (1997) ArticleTitleHow reproducible are measures of the anal sphincter muscle diameter by endoanal ultrasound Am J Gastroenterol 92 293–296

    Google Scholar 

  15. DM Gold S Halligan WA Kmiot CI Bartram (1999) ArticleTitleIntraobserver and interobserver agreement in anal endosonography Br J Surg 86 371–375

    Google Scholar 

  16. NM deSouza WA Kmiot R Puni et al. (1995) ArticleTitleHigh resolution magnetic resonance imaging of the anal sphincter using an internal coil Gut 37 284–287

    Google Scholar 

  17. JW Briel J Stoker E Rociu JS Lameris WC Hop WR Schouten (1999) ArticleTitleExternal anal sphincter atrophy on endoanal magnetic resonance imaging adversely affects continence after sphincteroplasty Br J Surg 86 1322–1327

    Google Scholar 

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Williams, A.B., Bartram, C.I., Halligan, S. et al. Endosonographic Anatomy of the Normal Anal Canal Compared with Endocoil Magnetic Resonance Imaging. Dis Colon Rectum 45, 176–183 (2002). https://doi.org/10.1007/s10350-004-6140-1

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  • DOI: https://doi.org/10.1007/s10350-004-6140-1

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