MRI DEFECOGRAPHY

MRI – Defecography Overview

Introduction  

Defecography using MRI (also referred to as MR Defecogram) is a specialized imaging procedure that is carried out with no invasiveness. It is used for examination of the pelvis floor and the anorectal region. During imaging the patient performs defecation. The scans are obtained in static and dynamic modes, which allows evaluating more precisely the abnormalities of morphology and functions accompanying constipation, incontinence, or pelvic organ prolapse. 

What is MRI Defecography? 

MRI Defecography examines the position and the activities of pelvic muscles and anorectal structures during palpation of the rectum to defecate. The contrast material which is usually ultrasound gel is injected into the rectum in the form of soft gel or paste. Then the patient is scanned while performing the following: squeezing, straining, and evacuation manoeuvres.

Parameters Considered in MRI Defecography

• Dynamics in rectal wall motion and its profile 
• Anal sphincter activity 
• Anorectal angle at rest and at strain level 
• Descent of pelvic organs 
• Presence Rectocele, enterocele, Intussusception or prolapse 

Reasons for the Test

• Explore the patients with difficult defecation for possible structural defects 
• Search for hidden rectal prolapse or intussusception. * Assess muscular coordination of pelvic floor.  
• Diagnose and plan appropriate surgery or nonsurgical management.  
• Identify functional vs structural causes of constipation.  

When and Who Needs MRI Defecography? 

Indications: 

• Trouble Bowel Movement (Outlet Obstruction Constipation) 
• Incomplete Evacuation of Contents 
• Prolapsed Rectum (External/Internal Prolapse) 
• Faecal Incontinence 
• Descent Or Dysfunction of the Pelvic Floor Organs 
• Enterocele, Cystocele, or Prolapse of the Uterus 
• Possible Animus or Dyssynergia Defecation Disorder 

Patient Demographics: 

• Chronic bowel symptom middle aged and elderly patients 
• Females post-delivery having pelvic floor prolapse 
• Patients with recurrent intra-abdominal pressure changes after pg. or pelvic surgery 
• Unexplained rectal symptom females and males 

Benefits of MRI Defecography

• No invasion and non-radiation.  
• Clear detail of many pelvic spaces (such as rectum, bladder, uterus) as well as layers.  
• Dynamic verification imaging during evacuation.  
• Greater soft tissue contrast than traditional X-ray defecography.  
• Can direct precision pelvic floor therapy or surgery.  

Conditions Diagnosed with MRI Defecography

• Rectocele  
• Enterocele  
• Intussusception  
• Pelvic organs prolapse  
• Animus: paradoxical puborectalis contraction  
• Perineal descent  
• Sphincter dysfunctions faecal incontinence  

Preparation for MRI Defecography

• Low residues diet the day before.  
• Mild laxative/enema the evening or morning prior.  
• Clear bladder before the scan.  
• Informed consent prior is needed prior to rectal gel insertion.  

Pre-requisites 

• Referral detailing symptoms such as explaining the rationale for imaging.  
• Other pelvic floor physiotherapy or surgical referrals can happen after depending on the findings.  
• MRI screening form to confirm no implants or for other contraindications to the procedure.  

Best Time for Test 

• After enduring ongoing symptoms of pelvic floor dysfunction.  
• Before surgical intervention for prolapse suspects.  
• Not responsive to conservative measures such as laxatives or physiotherapy.  

Eligibility for MRI Defecography 

• Adults and geriatrics with defecatory and continence disorders. 
• Patients with severe mobility restrictions or inability to cooperate may not be appropriate candidates.  
• Patients having implants or devices that are not compatible with MRI are contraindicated.  

MRI Defecography Procedure 

• Patient is positioned on the MRI bed (usually in slight upright sitting or relaxed supine position).  
• Rectum is distended with ultrasound gel/ jelly-like substance. 
• Initial static images are taken. 
• Patient is instructed to perform the following actions: squeeze, bear down, and evacuate. 
• Each phase is recorded dynamically.  
• Total Scan time: ~30-45 minutes.  

Caution During MRI Defecography 

• During insertion of gel, there is mild discomfort.  
• Fulfilling instructions on straining and evacuation is required.  
• Privacy and dignity are upheld during the procedure.