Indications for mri proctogram scan

> Descending perineum syndrome
> Internal rectal intussusception
> Difficulty in opening bowel
> Obstructed defecation
> Faecal incontinence
> Pelvic floor dysfunction
> Rectal prolapse
> Sigmoidocele
> Rectocele
> Enterocele
> Anismus

Contraindications





Any electrically, magnetically or mechanically activated implant (e.g. cardiac pacemaker, insulin pump biostimulator, neurostimulator, cochlear implant, and hearing aids)
Intracranial aneurysm clips (unless made of titanium)
Pregnancy (risk vs benefit ratio to be assessed)
Ferromagnetic surgical clips or staples
Metallic foreign body in the eye
Metal shrapnel or bullet

Patient preparation

 






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It is important that the bowel is clean and empty before the procedure. Patient should be supplied with a laxative suppository and instructions leaflet for how to insert the suppository. The suppository should insert into the rectum on the morning of the test. Instruct the patient to retain the suppository for 15 minutes and then empty your bowel completely.
A satisfactory written consent form must be taken from the patient before entering the scanner room
Ask the patient to remove all metal object including keys, coins, wallet, any cards with magnetic strips, jewellery, hearing aid and hairpins
Ask the patient to undress and change into a hospital gown
If possible provide a chaperone for claustrophobic patients (e.g. relative or staff )

Offer earplugs or headphones, possibly with music for extra comfort
Explain the procedure to the patient
Instruct the patient to keep still
Note the weight of the patient

Positioning


 
 

 


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Before positioning the patient place some inco pads over the table (over the spine coil) and cover it with a disposable couch roll. Now position the patient over the couch roll in supine position with head pointing towards the magnet (head first supine)
Position the patient over the spine coil and place the body coil over the pelvis(two inches above iliac crest down to three inches below symphysis pubis)
Securely tighten the body coil using straps to prevent respiratory artefacts
Give a pillow under the head for extra comfort (do not give cushions under the legs )
Centre the laser beam localiser over anterior superior iliac spine (2 inches below iliac crest)

Suggested protocols, parameters and planning

localiser

A three plane localiser must be taken in the beginning to localise and plan the sequences. Localisers are normally less than 25sec. T1 weighted low resolution scans.

T2 tse sagittal 3mm SFOV pre proctogram

Plan the sagittal slices on the axial plane; angle the position block parallel to the line along the interpubic fibrocartilage and the anal canal. Check the positioning block in the other two planes. An appropriate angle must be given in the coronal plane (parallel to the line along the rectum and the anal canal). Slices must be sufficient to cover the whole pelvis from the right acetabulum to the left acetabulum. FOV must be big enough to cover the whole pelvis (normally 270mm-300mm). Adding saturation bands on top and front of the sagittal block will reduce artifacts from arterial pulsation and breathing.

Parameters

TR

3000-4000

TE

100-120

SLICE

3 MM

FLIP

130-150

PHASE

A>P

MATRIX

320X320

FOV

270-300

GAP

10%

NEX(AVRAGE)

3

T2 tse axial oblique 3mm SFOV pre proctogram

Plan the axial oblique slices on the sagittal plane; angle the position block perpendicular to the anal canal. Check the positioning block in the other two planes. An appropriate angle must be given in the coronal plane (perpendicular to anal canal ). Slices must be sufficient to cover the whole anal canal.

Parameters

TR

3000-4000

TE

100-120

SLICE

3 MM

FLIP

130-150

PHASE

A>P

MATRIX

320X256

FOV

180-230

GAP

10%

NEX(AVRAGE)

5

T2 tse coronal oblique 3mm SFOV pre proctogram

Plan the coronal oblique slices on the sagittal plane; angle the position block parallel to the anal canal. Check the positioning block in the other two planes. An appropriate angle must be given in the axial plane (horizontally across the anal canal or parallel to the right and left hip joint). Slices must be sufficient to cover the whole anal canal.

Parameters

TR

3000-4000

TE

100-120

SLICE

3 MM

FLIP

130-150

PHASE

R>L

MATRIX

320X256

FOV

180-230

GAP

10%

NEX(AVRAGE)

5

pause for proctogram

Now move the patient out   and ask them to lie down in prone position. Now the radiologist will insert a small catheter in to the rectum using kyjelly for lubrication. Then the radiologist will inject small amount of ultrasound jel into the rectum. Now remove the catheter and position the patient back in to the same position. Instructions should be given to the patient to clench, relax and strain while pictures are taken.

localiser

A three plane localiser must be taken to localize and plan the sequences. Localisers are normally less than 25sec. T1 weighted low resolution scans.

 

T2 trufi cine small fov 10mm 1.5 sconds 100 measurements

Plan the sagittal slices on the axial plane; angle the position block parallel to the line along the interpubic fibrocartilage and the anal canal. Check the positioning block in the other two planes. An appropriate angle must be given in the coronal plane (parallel to the line along the rectum and the anal canal). Slice must be positioned over the middle of rectum and anal canal.

Approximately after 5 measurements ask the patient to strain and empty this gel from the rectum onto the inco pads underneath (cine scans should be running while the patient doing these).

Parameters

TR

40-50

TE

1-2

SLICE

5-10 MM

FLIP

70

PHASE

A>P

MATRIX

208X208

FOV

250-300

OVERS.

50%

CINE

100measurement

 

CLICK THE SEQUENCES BELOW TO CHECK THE SCANS