MRI T2-Weighted Imaging and Fat-Suppressed T2-Weighted Imaging Image Fusion Technology Improves Image Discriminablity for the Evaluation of Anal Fistulas

Shi-Ting Feng, Mengqi Huang, Zhi Dong, Ling Xu, Yin Li, Yingmei Jia, Huasong Cai, Bingqi Shen, Zi-Ping Li

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5 Citations (Scopus)


Objective: To explore whether MRI fusion technology (combined T2-weighted imaging [T2WI] and fat-suppressed T2WI [T2WI-(FS)]) improves signal differences between anal fistulas and surrounding structures.

Materials and Methods: A total of 32 patients with confirmed diagnoses of anal fistula were retrospectively studied. All available T2WI and T2WI-(FS) images for each patient were used to generate fusion image (T2WI-(Fusion)) based on the addition of Fusion, gray values obtained from each pixel via an MR post-processing work station. The discriminability of fistula, perianal sphincter, and perianal fat in T2WI, T2WI-(FS), and T2WI-(Fusion) images was quantified with Fisher's scoring algorithm. For subjective visual image assessment by researchers, five-point scale scores were determined using a modified double-stimulus continuous quality-scale test to evaluate T2WI-(FS), T2WI, enhanced axial three-dimensional-volumetric interpolated breath-hold examination (3D-VIBE), and T2WI-(Fusion) sequence images. The differences were subsequently compared.

Results: Mean Fisher scores for fistulas vs. sphincters obtained from T2WI-(Fusion) (F-(Fusion-fistula) = 6.56) were significantly higher than those from T2WI (F-T2WI(-fistula) = 3.35) (p = 0.001). Mean Fisher scores for sphincters vs. fat from T2WI-(Fusion) (F-(Fusion-sphincter) = 10.84) were significantly higher than those from T2WI-(FS) (FSFS-sphincter = 2.57) (p = 0.001). In human assessment, T2WI-(Fusion) showed the same fistula discriminability as T2WI-(FS), and better sphincter discriminability than T2WI. Overall, T2WI-(Fusion) showed better discriminability than T2WI, T2WI-(FS), and enhanced 3D-VIBE images.

Conclusion: T2WI and T2WI-(FS) fusion technology improves signal differences between anal fistulas and surrounding structures, and may facilitate better evaluation of anal fistulas and sphincters.

Original languageEnglish
Number of pages9
JournalKorean Journal of Radiology
Issue number3
Publication statusPublished - Mar 2019

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