This article was published online on 29 November 2011. Subsequently, an error was identified and the article was corrected on 27 January 2012.
Diffusion tensor imaging of the anal canal at 3 tesla: Feasibility and reproducibility of anisotropy measures†
Article first published online: 29 NOV 2011
Copyright © 2011 Wiley Periodicals, Inc.
Journal of Magnetic Resonance Imaging
Volume 35, Issue 4, pages 820–826, April 2012
How to Cite
Goh, V., Tam, E., Taylor, N. J., Stirling, J. J., Simcock, I. C., Jones, R. G. and Padhani, A. R. (2012), Diffusion tensor imaging of the anal canal at 3 tesla: Feasibility and reproducibility of anisotropy measures. J. Magn. Reson. Imaging, 35: 820–826. doi: 10.1002/jmri.22873
- Issue published online: 20 MAR 2012
- Article first published online: 29 NOV 2011
- Manuscript Accepted: 4 OCT 2011
- Manuscript Received: 8 FEB 2011
- magnetic resonance imaging;
- diffusion tensor imaging;
To assess the feasibility and reproducibility of 3-tesla diffusion tensor imaging (DTI) of the anal canal.
Materials and Methods:
DTI was performed in 25 men with no clinical history of anal canal disease undergoing MRI for prostate cancer. Analysis of fractional anisotropy (FA), relative anisotropy (RA), and apparent diffusion coefficient (ADC) were determined for the epithelial/subepithelial layer, internal sphincter, external sphincter, and puborectalis. The directionality of diffusion was recorded from color-coded tractography maps. Obturator internus and gluteus maximus served as reference muscles. Mean (SD) of values for FA, RA, and ADC were compared using analysis of variance. Intra and inter-rater agreement and test reproducibility (n = 5) was assessed by Bland-Altman statistics.
Mean (SD) for the epithelial/subepithelial layer, internal, external sphincter, and puborectalis were as follows: FA: 0.283 (0.099); 0.337 (0.049); 0.415 (0.072); and 0.407 (0.062), respectively. RA: 0.241 (0.094); 0.292 (0.050); 0.371 (0.083); 0.361 (0.067), respectively; and ADC: 1.49 (0.23); 1.59 (0.19); 1.51 (0.28); and 1.54 (0.29) × 10−3mm2/s, respectively. Good overall intra and inter-rater agreement and test–retest reproducibility was noted (coefficient of variation of 4.8–19.4% and 5.9–12.9%, respectively).
Anisotropy is evident in the anal canal with good inter-rater agreement and test reproducibility. J. Magn. Reson. Imaging 2012;35:820–826. © 2011 Wiley Periodicals, Inc.