Fistulogram MRI

Magnetic resonance imaging ( MRI scan ) fistulogram is an imaging technique used before surgery for conditions such as anal, anovaginal, or rectovaginal fistulas .

The problem of anal fistula is less seen in which a small tunnel starts forming in the skin near it inside the anus.

It is usually caused by an infection of the glands inside the anus that make pus. When the pus makes its way from the infected gland to the skin and starts to come out, it leaves a tunnel behind. Anal fistula does not go away on its own and in most cases it requires surgery.

Anovaginal and rectovaginal fistula is a passageway between the anus or rectum and the vagina. This can be caused by radiation therapy , inflammatory bowel disease , or surgical trauma.

An MRI scan uses a strong magnetic field and radio waves to produce detailed pictures of structures inside the body.

MRI fistulogram shows the location of the fistula passage. This helps in detecting any abscess and helps in locating the external and internal opening of the fistula before surgery.

Who cannot get fistulogram MRI done?

People with the following medical implants cannot have an MRI scan without a safety check:

ear transplant

Certain types of metal coils may be placed inside the blood vessels.

artificial joint

Pacemakers and Cardiac Defibrillators

Some types of clips used for brain aneurysms

It is also advised not to do MRI in the first trimester of pregnancy .

Why is fistulogram MRI done?

MRI fistulogram is the best option for the diagnosis of anal fistula. This scan is also a good option for detecting anovaginal and rectovaginal fistulas.

An MRI fistulogram scan reveals the following:

Fistula passage detection

planning surgery for fistula,

to identify associated abscesses

Doctors recommend this test if you have the following symptoms of anal fistula:

redness and swelling around the anus

skin irritation around the anus

fever

difficulty in holding a stool in some cases

foul-smelling discharge from the anus

blood or pus in the stool

Stinging pain is continuously felt in the rectal region which gets worse on sitting, walking, coughing and passing stool.

Doctors may also recommend this scan in the following symptoms of anovaginal or rectovaginal fistula:

passing stool and gas from the vagina

vaginal discharge

vaginal swelling

Contrast enhanced MRI fistulogram may be performed for conditions such as Crohn's disease as it helps to localize and reach disease progression.

A non-contrast enhanced MRI fistulogram may be done immediately after the operation to assess the process. During surgery, a fat-rich graft is used to fill the fistula.

Noncontrast MRI also helps to visualize the residual tract of the fistula and differentiate it from piles immediately after operation as piles show up more clearly on noncontrast MRI.

Preparation before MRI fistulogram :

If the doctor does not refuse, then you can take food and medicines. You may be asked to wear a hospital gown for the scan, or loose clothing if you are wearing one, but nothing metallic.

If you are pregnant, tell the doctor. Inform the doctor if you have recently had any surgery or have any health problems.

Metal objects are not allowed inside the scan room as they may be affected by the magnetic field and may pose a safety risk. Keep the following things out of the MRI scan room:

Jewelry, Credit Cards, and Body Piercing

Hearing aids, glasses and removable dental work

Hair accessories, metal zippers and any other metal items

pen and pocket knife

watches, mobile phones and other electronic items

If you have any medical device implanted, it may affect the MRI scan. If any shrapnel, bullet or other metal object is lodged in the body, especially near the eye, tell the doctor. This may cause heat build up or movement during imaging and may cause blindness.

If you are afraid of closed spaces, your doctor may give you sedation before the test. Gadolinium contrast dye can be used for contrast MRI. Tell your doctor if you have any allergies or asthma .

If you are allergic to contrast dye, your doctor may prescribe medication before the scan. A special contrast dye will be needed if you have a disease such as severe kidney disease. Before the scan, some tests can be done to know whether the kidney is working properly or not.

How is fistulogram MRI done?

The procedure for MRI fistulogram is as follows:

You will be asked to lie down on a movable examination table. A strap can be used to keep you from moving during the scan.

A device with a coil that can receive and send radio waves will be placed over the area to be scanned.

You will then be moved to the center of the scanner and a technologist will work on a computer outside the room to take the images.

Sometimes a gadolinium contrast rectal enema is given through a catheter, especially if the scan does not show a fistula.

The catheter will be taken out and you will be asked to have a bowel movement. This is done to apply pressure to the contrast through the fistula due to increased rectal pressure. After this it is scanned again.

Usually this scan takes half an hour to 50 minutes.

What does it feel like during a fistulogram MRI?

There is no pain in this scan but you may feel a little uncomfortable while lying flat during the procedure.

The machine can make noise while taking pictures but you will be provided with ear plugs to reduce the noise. The area to be scanned may feel slightly warm but this is normal.

Fistulogram MRI Scan Result :

MRI fistulogram shows the following types of fistula:

perineal fistula

anovaginal fistula

rectovaginal fistula

Advantages of Fistulogram MRI:

Fistula access accuracy

Proper planning of fistula surgery

less wear and tear

There is no need for much ripping process, it gets enough information

have not been exposed to any radiation

Risks of Fistulogram MRI :

Strong magnetic fields may affect the function of the implanted device or corrupt the images.

Strong magnetic fields in the first trimester of pregnancy can harm the baby.

What happens after MRI fistulogram?

If anesthesia is not given then you will not take any time to recover and after the test you will be normal as before.

What other tests can be done along with MRI fistulogram?

The following tests may be done along with an MRI fistulogram:

rectal examination

ultrasound

CT scan

proctoscopy