1. Seow-Choen F, Nicholls RJ. Anal fistula. Br J Surg. 1992; 79:197–205.
2. Practice parameters for treatment of fistula-in-ano--supporting documentation. The Standards Practice Task Force. The American Society of Colon and Rectal Surgeons. Dis Colon Rectum. 1996; 39:1363–1137.
3. Lilius HG. Fistula-in-ano, an investigation of human foetal anal ducts and intramuscular glands and a clinical study of 150 patients. Acta Chir Scand Suppl. 1968; 383:7–88.
4. Seow-Choen , Phillips RK. Insights gained from the management of problematical anal fistulae at St. Mark's Hospital, 1984-88. Br J Surg. 1991; 78:539–541.
5. Bartram C, Buchanan G. Imaging anal fistula. Radiol Clin North Am. 2003; 41:443–457.
6. de Miguel Criado J, del Salto LG, Rivas PF, del Hoyo LF, Velasco LG, de las Vacas MI, et al. MR imaging evaluation of perianal fistulas: spectrum of imaging features. Radiographics. 2012; 32:175–194.
7. Yousem DM, Fishman EK, Jones B. Crohn disease: perirectal and perianal findings at CT. Radiology. 1988; 167:331–334.
8. Kalra MK, Woisetschläger M, Dahlström N, Singh S, Lindblom M, Choy G, et al. Radiation dose reduction with Sinogram Affirmed Iterative Reconstruction technique for abdominal computed tomography. J Comput Assist Tomogr. 2012; 36:339–346.
9. Tio TL, Mulder CJ, Wijers OB, Sars PR, Tytgat GN. Endosonography of peri-anal and peri-colorectal fistula and/or abscess in Crohn's disease. Gastrointest Endosc. 1990; 36:331–336.
10. Lunniss PJ, Phillips RK. Anatomy and function of the anal longitudinal muscle. Br J Surg. 1992; 79:882–884.
11. Proscia N, Jaffe TA, Neville AM, Wang CL, Dale BM, Merkle EM. MRI of the pelvis in women: 3D versus 2D T2-weighted technique. AJR Am J Roentgenol. 2010; 195:254–259.
12. Kim H, Lim JS, Choi JY, Park J, Chung YE, Kim MJ, et al. Rectal cancer: comparison of accuracy of local-regional staging with two- and three-dimensional preoperative 3-T MR imaging. Radiology. 2010; 254:485–492.
13. Fütterer JJ, Yakar D, Strijk SP, Barentsz JO. Preoperative 3T MR imaging of rectal cancer: local staging accuracy using a two-dimensional and three-dimensional T2-weighted turbo spin echo sequence. Eur J Radiol. 2008; 65:66–71.
14. Flohr T, Stierstorfer K, Raupach R, Ulzheimer S, Bruder H. Performance evaluation of a 64-slice CT system with z-flying focal spot. Rofo. 2004; 176:1803–1810.
15. Lichy MP, Wietek BM, Mugler JP 3rd, Horger W, Menzel MI, Anastasiadis A, et al. Magnetic resonance imaging of the body trunk using a single-slab, 3-dimensional, T2-weighted turbo-spin-echo sequence with high sampling efficiency (SPACE) for high spatial resolution imaging: initial clinical experiences. Invest Radiol. 2005; 40:754–760.
16. Halligan S, Stoker J. Imaging of fistula in ano. Radiology. 2006; 239:18–33.
17. Liang C, Jiang W, Zhao B, Zhang Y, Du Y, Lu Y. CT imaging with fistulography for perianal fistula: does it really help the surgeon? Clin Imaging. 2013; 37:1069–1076.
18. Parks AG, Gordon PH, Hardcastle JD. A classification of fistula-in-ano. Br J Surg. 1976; 63:1–12.
19. Spencer JA, Chapple K, Wilson D, Ward J, Windsor AC, Ambrose NS. Outcome after surgery for perianal fistula: predictive value of MR imaging. AJR Am J Roentgenol. 1998; 171:403–406.
20. Chapple KS, Spencer JA, Windsor AC, Wilson D, Ward J, Ambrose NS. Prognostic value of magnetic resonance imaging in the management of fistula-in-ano. Dis Colon Rectum. 2000; 43:511–516.
21. Harisinghani MG, Gervais DA, Hahn PF, Cho CH, Jhaveri K, Varghese J, et al. CT-guided transgluteal drainage of deep pelvic abscesses: indications, technique, procedure-related complications, and clinical outcome. Radiographics. 2002; 22:1353–1367.