Application of multimodal MRI sequences in Parks classification and lesion detection in patients with anal fistula of damp-heat downward pouring pattern
HONG Qi
LI Juan
ZHU Biao
JIANG Shenlin
PENG Hong
Abstract：Objective To investigate the application value of multimodal magnetic resonance imaging(MRI)se-quences in preoperative Parks classification and lesion detection for patients with dampness-heat downward pouring type anal fistula.Methods Seventy-two patients with dampness-heat downward pouring type anal fistula were enrolled.All underwent surgical treatment and preoperative multimodal MRI sequences,including:diffusion-weighted imaging(DWI),fat-suppressed T2-weighted imaging(T2WI FS),fat-suppressed T1-weighted three-dimensional gradient-echo sequence(T1 VIBE FS)enhanced scanning.Kappa consistency test was used to evaluate agreement between preoperative MRI findings and intraoperative diagnosis.The detection concordance rates of three sequences for lesions(internal openings,fistula tracts,and abscesses)were calculated and compared.Results In the Parks classification of 72 cases of anal fistulas with damp-heat downward pouring type,there are 42 cases of intersphincteric type,15 cases of transsphincteric type,7 cases of suprasphincteric type,and 2 cases of extrasphincteric type.The Kappa value for MRI-based Parks classification versus intraoperative diagnosis was 0.848(P<0.001).Intraoperative and pathological confirmation identified 81 internal openings,90 fistula tracts,and 22 perianal abscesses among 72 patients.All MRI images met diagnostic quality criteria.Internal openings and fistula tracts exhibited high signal intensity on T2WI FS and DWI.Enhanced scans showed punctate/rim enhancement of internal openings and linear/tubular enhancement of fistula tracts.Abscesses demonstrated high sig-nal on T2WI FS and DWI,with rim enhancement of walls and non-enhancing cavities.T1 VIBE FS enhanced scanning showed significantly higher coincidence rates than DWI and T2WI FS for internal openings(both P<0.05)and higher coin-cidence rate than DWI for fistula tracts(all P<0.05).All three sequences achieved 100%coincidence rate for abscess de-tection.Conclusion The results of multimodal MRI sequence examination for Parks classification of anal fistula of damp-heat downward pouring type are highly consistent with the intraoperative diagnostic results;the detection coinci-dence rate of internal openings and fistulas by T1 VIBE FS enhanced scan is higher than that by DWI and T2WI FS,and all three sequences can accurately detect perianal abscesses.
Keywords：anal fistuladampness-heat downward pouring syndromemultimodal MRIParks classificationin-ternal openingfistula tractperianal abscess
Publication Date：2025-08-25
Online Publishing Date：2025-09-10(First online date of this platform, not the publication date of the document)
Pages：5( 85-89 )