Evaluation of perianal fistulas with magnetic resonance imaging: Significance of T2-weighted BLADE sequence in disease diagnosis

Abstract

Aim: Anatomical details of perianal fistulas can be revealed more clearly by T2-weighted (T2-W) periodically rotated overlapping parallel lines with enhanced reconstruction (BLADE) sequence during magnetic resonance imaging (MRI). This study aimed to compare the efficacy of the T2-W BLADE sequence and the T2-W turbo spin echo (TSE) sequence in diagnosing perianal fistula, as well as to compare the findings with the results obtained using the dynamic contrast-enhanced (DCE) T1-weighted (T1-W) sequence during routine pelvic MRI examination. Methods: Ninety patients (male/female: 67/23) who had undergone pelvic MRI examination (1.5Tesla) for the prediagnosis of perianal fistula were included in this prospective study. In addition to our routine pelvic MRI protocol, T2-W BLADE sequence imaging and T2-W TSE sequence imaging in the axial, sagittal, and coronal planes were performed. Using a three-stage scoring system, two radiologists independently compared the T2-W BLADE and T2-W TSE sequences with each other and then with the DCE T1-W sequence in terms of perianal fistula imaging. Statistical analysis was performed using a sample t-test and the Cronbach’s α test. Results: Compared with the T2-W TSE sequence, the T2-W BLADE sequence was associated with fewer ghosting artifacts, with higher overall image quality, and with clearer visualization of the anatomical details of perianal fistula (p < 0.05). Images with high anatomic details and contrast resolution were obtained using the T2-W BLADE sequence similar to those obtained using the DCE T1-W sequence (p < 0.05). Conclusion: On the basis of the reduced imaging time and on the higher image resolution, T2-W images can be obtained with the BLADE technique for the diagnosis of perianal fistula.