Perianal fistula:MRI classification and DWI features / 实用放射学杂志

ABSTRACT

Objective MRI findings of 1 6 perianal fistula patients were retrospectively analyzed to improve the value of imaging diagnosis and to help making clinical management.Methods 1 6 cases of periansl fistula were classified by Parks classification and St.James University hospital grades.MRI manifestations were compared with operation results,and diffusion weighted imaging (DWI)features were observed.Results According to Parks classification,there were 7 cases of intersphincteric fistula and trans-sphincteric fistula,respectively,1 case of suprasphincteric fistula and extrasphincteric fistula,respectively.According to St.James University hospital grades,there were 5 cases of grade Ⅰ,2 cases of grade Ⅱ,5 cases of grade Ⅲ,2 cases of grade Ⅳ and 2 cases of grade Ⅴ.MR imaging had a sensitivity of 93.75% and a specificity of 100% for detecting perianal fistula.Displaying rate of in-ternal opening was 79.1 7%.Only 3 cases with perianal abscess could be clearly detected on DWI.Conclusion MRI can be used to identify the internal fistula opening and the course of perianal fistula,determine the location and shape of abscess,as well as whether they combined with branch.MRI may provide excellent anatomic and pathologic information for classification and clinical manage-ment.But DWI has limited value for detection of perianal fistula.