Abstract

 
BACKGROUND:
and other inflammatory diseases of the anusand perianal soft tissues area cause perianal fistulas substantial morbidity.Diffusion-weighted magnetic resonance imaging (MRI) plays a great role in the evaluation of anal fistulae.
OBJECTIVE:
To evaluate the value of DWI in the examination of perianal fistula.
PATIENTS AND METHODS:
The study included 38 patients (30 males and 8 females) with clinical suspicion of perianal fistula. It was done in MRI department (3.0T) of AL-Imamain AL-Kadhimyianmedical city, Baghdad/ Iraq during the period from November 2020 to January 2021. MRI images were assessed for the presence of visible fistulas, internal openings, secondary extension, horse shoe and abscess.
RESULTS:
68.4% of the fistulas were at Lt. side and 31.6% in the Rt. Side. Intra-sphincteric was 63.2%, trans-sphincteric was 31.6% and supra-sphinctericwas 5.3%. The primary tract detection rate at T1 was 81.6%, at T2 was 92.1%. The internal opening, the detection rate in T1 was only 10.5%, at T2  was 21.1%, at T2 Fat was 81.6%, T1+contrast was 63.2%, at DWI was 89.5% and T2 Fat+DWI was 100%. (P< 0.001. The detection rates at T2 fat sat, T1+contrast, DWI and T2 fat sat+DWI were 100%, 89.5%, 86.6% and 100%, respectively, indicating a higher detection rate at T2 sequence and T2 fat sat+DWI, with highly significant differences (p<0.001). According to the detection rates reported above, the best accuracy rate in combined T2 Fat+DWI, (P< 0.001, highly significant).
CONCLUSION:
Both DWI and CE sequences have high accuracy in the diagnosis and detecting complications of PAF. The combined FS-T2W + DWI and FST2W + CE data sets have equal sensitivity and specificity, and the use of the combined FS-T2W + DWI data set can prevent unnecessary use of contrast agent and prevent both cost and contrast-related complications.