Objective:

To investigate the value of two-dimensional endoanal ultrasound (2D-EAUS) and three-dimensional en-doanal ultrasound (3D-EAUS) in diagnosis of anal fistula.

Methods:

Endoanal ultrasound image data of 57 patients with anal fistula was collected and compared to the intraoperative findings using kappa coefficient test.

Results:

3D-EAUS had better concordance with intraoperative finding in the diagnosis of internal opening as compared to 2D-EAUS (Kappa: 0.791

vs

0.482). There was a good concordance be

tween intraoperative findings and the 2D-EAUS or 3D-EAUS results in the diagnosis of the primary tract

secondary tract

and adjacent abscesses. 2D-EAUS showed a small advantage on 3D-EAUS in the diagnosis of the intrasphincteric fistula (Kappa: 1.000

vs

0.926)

on the contrary 3D-EAUS was better than 2D-EAUS in the diagnosis of the secondary tract (Kappa: 1.000

vs

0.814).

Conclusion:

Both 2D-EAUS and 3D-EAUS is good to diagnosis of anal fistula.