Measurement of rectal tumor height from the anal verge on MRI: A comparison of internal versus external anal sphincter Journal Article


Authors: Bates, D. D. B.; Fuqua, J. L. 3rd; Zheng, J.; Capanu, M.; Golia Pernicka, J. S.; Javed-Tayyab, S.; Paroder, V.; Petkovska, I.; Gollub, M. J.
Article Title: Measurement of rectal tumor height from the anal verge on MRI: A comparison of internal versus external anal sphincter
Abstract: Purpose: To determine the most accurate measurement technique to assess rectal tumor height on MRI using two different anatomic landmarks for the anal verge. Introduction: Accurate measurements and standardized reporting of MRI for rectal cancer staging is essential. It is not known whether measurements starting from the internal anal sphincter (IAS) or external anal sphincter (EAS) more closely correlate with tumor height from the anal verge on endoscopy. Methods: This retrospective study included baseline staging MRI examinations for 85 patients after exclusions. Two radiologists blinded to endoscopic results measured the distance of rectal tumors from the internal anal sphincter and external anal sphincter on sagittal T2 images. The reference standard was endoscopic measurement of tumor height; descriptive statistics were performed. Results: For reader 1, the mean difference in measurement of tumor height between MRI and endoscopy was − 0.45 cm (SD ± 1.76 cm, range − 6.0 to 3.9 cm) for the IAS and 0.51 cm (SD ± 1.75 cm range − 4.7 to 4.8 cm) for the EAS. For reader 2, the mean difference in measurement of tumor height between MRI and endoscopy was − 0.57 (STD ± 1.81, range − 5.9 to 4.8 cm) for the IAS and 0.52 cm (STD ± 1.85, range − 4.3 to 5.6 cm) for the EAS. Interobserver ICC was excellent between reader 1 and reader 2 for measurements from both the IAS (0.955 95% CI 0.931–0.97) and EAS (0.952, 95% CI 0.928, 0.969). Conclusion: Measurement of tumor height on MRI was highly reproducible between readers; beginning measurements from the EAS tends to slightly overestimate tumor height on average and from the IAS tends to slightly underestimate tumor height on average. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
Keywords: measurement; rectal cancer; anal canal; rectal mri; anal verge; tumor height
Journal Title: Abdominal Radiology
Volume: 46
Issue: 3
ISSN: 2366-004X
Publisher: Springer  
Date Published: 2021-03-01
Start Page: 867
End Page: 872
Language: English
DOI: 10.1007/s00261-020-02757-3
PUBMED: 32940753
PROVIDER: scopus
PMCID: PMC7946652
DOI/URL:
Notes: Article -- Export Date: 1 April 2021 -- Source: Scopus
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MSK Authors
  1. Junting Zheng
    200 Zheng
  2. Marc J Gollub
    208 Gollub
  3. Marinela Capanu
    385 Capanu
  4. Viktoriya Paroder
    60 Paroder
  5. David Dawson Bartlett Bates
    53 Bates