Added value of Diffusion-Weighted Images & Contrast Enhanced Magnetic Resonance Imaging for the Diagnosis of Perianal Fistula

Document Type : Original research articles


Diagnostic Radiology Department, Faculty of Medicine, Tanta University, Tanta, Egypt


Background:  The perianal surgical procedure is aimed at removing all infection sources related to the fistula and its tract, while preserving anal sphincter functions. Various peri-operative risk factors impact perianal fistula recurrence. Managing perianal fistula faces many challenges. MRI represents the preferred imaging technique for detecting the fistula's type as well as related adverse events
Objectives: This work was aimed at differentiating between plain, DWI as well as contrast MRI studies, thus establishing the final protocol.
Patients and methods: This prospective non-randomized study included a sample of 80 cases suspected to have perianal fistula, MRI was done for all of them including T2, contrast injection & DWI. The radio logical findings were correlated with surgical outcome.
Results: This study included 80 patients developing perianal discharge or external perianal fistulous opening, contrast deemed to be beneficial within twenty-eight  subjects since the enhancement of perifistulous inflammatory changes as well as the abscesses exhibited better delineation. Regarding to original tract; there was an agreement between Plain T2 and (DWI, contrast and surgery) while there was no agreement between DWI and (contrast and surgery) . Regarding to fibrosed tract, abscess and 2ry tract; there was an agreement between the four groups.. Regarding to internal opining; there was no agreement between Plain T2 and DWI and between DWI and (contrast and surgery) (P value =0.001).
Conclusions: DWI represents a beneficial tool while assessing perianal fistula, yet contrast administration exhibits more sensitivity as well as specificity when identifying fistulas as well as their complications.  It can be reliable especially in patient with any contraindication to contrast injection.


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