MRI Fistulogram

What the Scan Shows

• The full course, length, and branching of a fistula
• Internal opening(s) inside the anal canal
• Presence of abscesses or secondary tracts
• Relationship to the anal sphincter muscles

Average Duration and Safety Profile

• Scan time: 25–35 minutes
• Radiation exposure: Zero
• Contraindications: Limited to certain implants; otherwise very safe

1. Non-contrast high-resolution T2

• Ideal for most simple fistulas
• No injection required

2. Contrast-enhanced (Gadolinium) study

• Highlights active inflammation and abscess pockets
• Requires IV cannula and kidney-function check The radiologist at Cadabams Diagnostics chooses the protocol based on clinical history provided by your referring doctor.

• Fistula tract course and length – helps decide incision site
• Internal opening location – critical to avoid muscle damage
• Abscess or secondary tracts – prevents missed infection
• Sphincter muscle involvement – influences surgical approach (sphincter-saving vs cutting)

• Pre-surgical planning: Guides safe, complete removal of the tract
• Recurrent or complex fistulas: Maps hidden branches missed earlier
• Evaluation of Crohn’s-related fistulas: Monitors disease activity and response to treatment

• Non-invasive – no scopes or needles (unless contrast is chosen)
• Zero ionising radiation – safe for repeated follow-ups
• Precise 3-D mapping – gives surgeons confidence and reduces risk of incomplete surgery
• Single-visit convenience – report ready in 2–4 hours at Cadabams Diagnostics

• Simple & complex perianal fistulas
• Supralevator & extrasphincteric extensions
• Perianal abscess (acute or chronic)
• Rarely, underlying cancer within a long-standing fistula tract

• Fasting: Light meal 2–4 hours before; avoid fizzy drinks
• Metal screening: Fill questionnaire at reception or online
• What to wear & bring:
• Cotton clothes without metal zippers
• Remove jewellery, watches, and credit cards
• Carry any previous reports or CDs for comparison

• Creatinine report (within 4 weeks) only if contrast is planned
• Signed consent for the scan and, if needed, IV gadolinium

• Morning slots (7 a.m.–11 a.m.) – bowel is quieter, image quality better
• Before elective surgery – schedule 1–7 days prior for freshest anatomy

• Adults & children ≥8 years – child-friendly staff and optional sedation
• Pregnancy: Generally deferred in first trimester; discuss risks vs benefits with your obstetrician

1. Patient positioning: Lying on your stomach or back; a surface coil is placed over the buttocks.
2. Sequence run-time: Around 30 minutes total; several short scans with brief breaks.
3. Post-procedure care:

• Resume normal diet immediately
• If contrast given, drink extra water to flush kidneys
• Leave with printed films and digital report on CD/USB

• Claustrophobia or anxiety: Inform staff; mild oral sedation can be arranged.
• Kidney function: eGFR <30 mL/min may limit contrast use; discuss with radiologist.

MRI Safety Considerations

• Absolute contraindications: Most pacemakers, cochlear implants, certain aneurysm clips
• Relative checks: Orthopaedic screws, IUDs, insulin pumps Cadabams Diagnostics performs a detailed metal-screening questionnaire and in-person review.

Limitations in Very Early or Superficial Fistulas

Tiny tracts less than 2 mm may not be visible. In such cases, clinical examination and endo-anal ultrasound remain complementary.