Including video and novel parameter-height of penetration of external anal sphincter-in magnetic resonance imaging reporting of anal fistula

Table 2 Format for reporting the fistula magnetic resonance imaging in the video

Axial Section T2-weighted
1 External opening- location
2 Define primary tracts
Location and course – Ischiorectal fossa/ Intersphincteric and clock-dial position
Location and ‘height’ of penetration of external anal sphincter (HOPE)- Point of penetration of external anal sphincter
Intersphincteric course
Location and height of internal opening- clock-dial position and whether it is at dentate line or higher
3 Secondary tracts
4 Associated abscesses
5 Supralevator extension
6 Additional internal opening
7 Sphincter anatomy
Axial section-STIR
1 Confirm findings of Axial-T2
2 Additional areas with inflammation
Coronal T2-weighted
1 Confirm findings of Axial-T2
2 Length of tract
3 Supralevator or suprasphincteric tract
4 Confirm the ‘height’ of penetration of external anal sphincter (HOPE) by the fistula tract – Indicates the amount of external sphincter involved
5 Confirm the ‘height’ of the site of internal opening
6 Extent of fistula tract in anterior fistulas- relation with urethra
7 Sphincter anatomy
Coronal section- STIR
1 Confirm findings of Coronal-T2
2 Good to detect thin Intersphincteric collections
Biplanar (Axial T-2 weighted + Coronal T-2 weighted)
1 Confirm the ‘height’ of the site of penetration of external sphincter by the fistula tract – Indicates the amount of external sphincter involved
2 Confirm the ‘height’ of the site of internal opening
Sagittal section
1 Extent of fistula tract in posterior fistulas- Relation with sacrococcygeal spine, presacral space
2 Extent of fistula tract in anterior fistulas- Relation with urethra