Gastrointestinal tract, Abdomen, MR, MR-Diffusion/Perfusion, Diagnostic procedure, Fistula, Abscess
L. A. M. S. Mohsen, N. Osman; Minia/EG
Aims and objectives
Perianal fistulas represent a common inflammatory condition of the anal canal and perianal tissues.
Most of these fistulas occur due to idiopathic inflammation of the cryptogenic glands in the anal mucosa.
Less common causes include Crohn’s disease,
child birth related trauma or radiotherapy.
MRI allows the direct visualization of the fistulous tract,
its site and the extent of the fistula - and its abscess - in relation to the anal sphincters and levator ani muscle.
This has further improved the surgical outcome for these patients.
Diffusion weighted imaging (DWI) is currently under investigation to evaluate whether it adds any value to the evaluation of perianal inflammation.
Some authors have suggested that DWI is more sensitive than T2W sequence regarding the visibility of the fistula.(1) Others suggested that restricted diffusion indicated activity of the fistula,
and some even suggested that it represents a good alternative for post-contrast imaging in case gadolinium can’t be used.(2,3) However,
these studies are still few and the applicability of DWI in the imaging of perianal fistulas is still questionable.
In this study,
we aimed to evaluate the value of adding DWI to the routine evaluation of perianal fistula.
We aimed to compare the visibility of perianal fistulas and abscesses and correlate the diffusion characteristics of the perianal fistulas and abscesses to the serum inflammatory markers.
James’s University Hospital classification of perianal fistulas based on DWI and combined DWI and T2W evaluation was also compared to this classification based on combined T2W and post-contrast T1W images.