Serdar ASLAN

Added value of contrast-enhanced and diffusion-weighted MRI data sets for characterization of perianal fistulas; single center experience

Aim: Our aim in this study is to determine the effectiveness of fat-suppressed T2-weighted (FS-T2W), FS-T2W+Diffusion-weighted image (DWI) and FS-T2W+Contrast-enhanced (CE) magnetic resonance imaging (MRI) data sets in the diagnosis of perianal fistula (PAF).Material and Methods: Retrospective analysis of 207 patients with a history of PAF operation between January 2018 and March 2020 was performed. The inclusion criteria were patients with PAF who underwent MRI prior to surgery and had a detailed intraoperative report. MRI data sets were evaluated by a radiologist, assessed fistula type, internal/external orifice position and presence of abscess/secondary tracts. The Cohen’s kappa (κ) statistic was used to define the level of between from intraoperative findings and MRI data sets agreement. The sensitivity and specificity were compared using the McNemar’s test.Results: All MRI data sets showed the presence of PAF correctly (n = 67, 100%). When the type of PAF per St James and AGA classification, presence of perianal abscesses/secondary tract agreement between intraoperative findings and MRI data sets is evaluated; moderate agreement for isolated FS-T2W data set, almost perfect agreement for combined FS-T2W+DWI and FS-T2W+CE data sets. In the evaluation of agreement for internal/external orifice position; substantial agreement for isolated FS-T2W data set, almost perfect agreement for combined FS-T2W+DWI and FS-T2W+CE data sets. Combined FS-T2W+DWI and FS-T2W+CE data sets have equal sensitivity and specificity each other (p = 0.544) and both data sets higher sensitivity and specificity than isolated FS-T2W data set (p < 0.001, p < 0.001, respectively).Conclusion: Adding DWI or CE data sets to the FS-T2W data set in the diagnosis of PAF has been shown to detect both diagnosis and complications with high accuracy. Combined FS-T2W+DWI and FS-T2W+CE data sets have equal sensitivity and specificity, and the use of the FS-T2W+DWI data set can prevent unnecessary use of contrast agent.

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1. Vanbeckevoort D, Bielen D, Vanslembrouck R, et al. Magnetic resonance imaging of perianal fistulas. Magn Reson Imaging Clin N Am 2014; 22:113-23.
2. Sainio P. Fistula-in-ano in a defined population. Incidence and epidemiological aspects. Ann Chir Gynaecol 1984;73:219-24
3. Parks AG, Gordon PH, Hardcastle JD. A classification of fistula-in-ano. Br J Surg 1976;63:1-12.
4. Jordan J, Roig JV, Garcia-Armengol J, et al. Risk factors for recurrence and incontinence after anal fistula surgery. Colorectal Dis 2010;12:254-60.
5. S Sahni VA, Ahmad R, Burling D. Which method is best for imagingof perianal fistula? Abdom Imaging 2008;33:26-30.
6. Spencer JA, Ward J, Beckingham IJ, et al. Dynamic contrast-enhanced MR imaging of perianal fistulas. Am J Roentgenol 1996;167:735-41.
7. Chrysochou C, Buckley DL, Dark P, et al. Gadoliniumenhanced magnetic resonance imaging for renovascular disease and nephrogenic systemic fibrosis: criticalreview of the literature and UK experience. J Magn Reson Imaging 2009; 29:887-94.
8. Wesbey GE, Moseley ME, Ehman RL. Translation molecular self-diffusion in magnetic resonance imaging. II. Measurement of the self-diffusion coefficient. Invest Radiol 1984;19:491-8.
9. Sandborn WJ, Fazio VW, Feagan BG, et al. AGA technical review on perianal Crohn’s disease. Gastroenterology 2003;125:1508-30.
10. de Miguel Criado J, del Salto LG, Rivas PF, et al. MR imaging evaluation of perianal fistulas: spectrum of imaging features. RadioGraphics 2012;32:175-94
11. Hori M, Oto A, Orrin S, et al. Diffusion-weighted MRI: a new tool for the diagnosis of fistula-in-ano. J Magn Reson Imaging 2009;30:1021-6.
12. Yoshizako T, Wada A, Takahara T, et al. Diffusionweighted MRI for evaluating perianal fistulaactivity: feasibility study. Eur J Radiol 2012;81:2049-53.
13. Cavusoglu M, Duran S, Sozmen Cılız D, et al. Added value of diffusion-weighted magnetic resonance imaging for the diagnosis of perianal fistula. Diagn Interv Imaging 2017;98:401-8.
14. Cattapan K, Chulroek T, Kordbacheh H, et al. Contrastvs. non-contrast enhanced MR data sets for characterization of perianal fistulas. Abdom Radiol (NY) 2019;44:446-55.
15. Singh K, Singh N, Thukral C, et al. Magnetic resonance imaging (MRI) evaluation of perianal fistulae with surgical correlation. J Clin Diagn Res 2014;8:01-4.