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MR DEFECOGRAM
EDUARDO D CAMPUZANO
BS,RT(R,MR,CT)
OBJECTIVES
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INDICATIONS
PREPARATIONS
PROTOCOL
FINDINGS
PITFALLS
SUMMARY
PELVIC FLOOR
• Pelvic Floor Disorders- Typically occur among women
who have given birth or have had a hysterectormy.
– General Pelvic pain , Urinary Incontinence , Constipation
– Usually characterized by abnormal pelvic organs displacement
– More than 300,000 surgeries annually.
DIAGNOSTIC MODALITIES
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Ultrasound- Depict the anal sphincter complex and associated
pathologic changes in exquisite anatomic detail.
Flouroscopy Defecography- Is considered the Gold Standard for
imaging Pelvic Floor disorder.
– Is invasive and requires opacification of Bladder,Vagina and Rectum.
– Uses Ionizing Radiation (Flouroscopy)
– Fails to recognize associated abnormalities of the anterior and
middle pelvic compartments.
PELVIC FLOOR ANATOMY
Three Compartments:
• Anterior Compartment – Bladder & Urethra
• Middle Compartment – Uterus,Cervix & Vagina
• Posterior Compartment – Ano-Rectum
Pelvic Diaphragm ( Levator Ani & Coccygeous Muscle Grpups)
PELVIC FLOOR ANATOMY
PELVIC FLOOR ANATOMY
Pubococcygeal Line (PCL) - The primary landmarks used to
assess pelvic support.
Prolapse “ Rule of Three”
• Organ below the PCL by 3 cm or less is mild
• Organ below the PCL ,between 3 and 6 cm is moderate
• Organ below the PCL by 6cm or more are severe.
MR DEFECOGRAM
Advantages :
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Elimination of ionizing radiation
Excellent depiction of surrounding soft tissues
Allows assessment of all three Compartments
No Intravenous Contrast is needed
Real Time imaging
Disadvantages :
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Claustro/Implants
30 minutes Exam
Cost
Uncooperative patient
PATIENT PREPARATION
• Bowel cleansing enema cleansing 12-24 hours prior to MRI
• Drink four cups of water (approx. 32 oz) over 30 min prior MRI.
- Distend Bladder(full bladder during exam).
• Provide diapers , gown and have Radiologist explain the procedure .
• Inject sonographic gel into vagina.
- Opacify/Identify vagina (Female Patients).
• Prepared and mixed gel with mashed potatoes .
- Doped with 1.5mL of gadolinium.
• Place patient in a right decubitus position
-200 ml of sonographic gel is put into the rectum
MR DEFECOGRAM
Supplies:
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Diapers
Bedpan
Gloves
Sonography Gel
60ml Syringes
Barium Enema Bag
KY Jelly (Lubricant)
Blue Chuks (Undercover)
Towels
SSFSE/HASTE (T2)
• Fast ,single shot (turbo spin echo)
• Relatively motion insensitive
• Sagittal Scout for True Pelvis
– Performed at Rest
– Use for PCL Baseline
Artifacts in Bladder
SSFP (T2*)
• Fast, single shot(steady state)
• Relatively motion insensitive
• Single Slice ,multiple measurement
– Use for Cine Evaluation (Real Time)
– No Cardiac or Respiratory Gating
Suceptibility Artifacts due to GRE
MR DEFECOGRAM
PROTOCOL
Protocol:
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Axial T2 TSE
T2 Haste Sagittal (Rest)
T2* SSFP Cine Sagittal (Rest)
T2* SSFP Cine Sagittal (Contraction)
T2* SSFP Cine Sagittal (Valsalva)
T2* SSFP Cine Coronal (Valsalva)
T2* SSFP Cine Axial (Valsalva)
T2* SSFP Cine Sagiital (Evacuation)
T2* SSFP Cine Coronal (Evacuation)
SSFP T2* Sagittal Cine
THREE POINT POSITIONING
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1. Pubic Symphysis
2. Rectum
3. Coccyx
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SSFP T2* Sagittal Cine Positioning
SSFP T2* (Cine) Sag Rest
PCL in One Image
SSFP T2* Sagittal Cine Positioning
SSFP T2* (Cine) Sag Rest
SSFP T2* (Cine) Sag Contraction
SSFP T2* Coronal Cine Positioning
Sag SSFP Cine
SSFP T2* (Cine) Cor
Need to be able to visualized Anal Sphinter
SSFP T2* Axial Cine Positioning
Sag SSFP Cine
SSFP T2* (Cine) Axial
MR DEFECOGRAM
NORMAL ANATOMY
MR DEFECOGRAM
Anterior Compartment
Pathology
Cystocele- Occurs when the supportive tissue between a
woman's bladder wall weakens and stretches, allowing the
bladder to bulge into the vagina.
MR DEFECOGRAM
Anterior Compartment
Pathology
Cystocele
MR DEFECOGRAM
Middle Compartment
Pathology
Vaginal Prolapse- Occurs when pelvic floor muscles and
ligaments stretch and weaken, providing inadequate
support for the uterus.
MR DEFECOGRAM
Middle Compartment
Pathology
REST
STRAIN
Vaginal Prolapse
MR DEFECOGRAM
Middle Compartment
Pathology
Enterocele - Occurs when the small intestine descends
into the lower pelvic cavity and pushes at the top part of
the vagina, creating a bulge.
MR DEFECOGRAM
Middle Compartment
Pathology
REST
STRAIN
Enterocele
MR DEFECOGRAM
Posterior Compartment
Pathology
Rectocele – Occurs when there is a herniation of the
rectum into the posterior vaginal wall that results in a
vaginal bulge.
MR DEFECOGRAM
Posterior Compartment
Pathology
Rectocele
MR DEFECOGRAM
Posterior Compartment
STRAIN
REST
Anorectal Angle
MR DEFECOGRAM
Posterior Compartment
Pathology
REST
Pelvic Dyssynergia
STRAIN
MR DEFECOGRAM
All Three Compartments
Pathology
PELVIC FLOOR
Treatment:
• Mild Cases - Kegel exercise
• Moderate Cases (Cystocele,Incotenience) – Pessary
may be used.
• Severe Cases (Rectocele,Constipation)- Surgery
may be necessary.
MR DEFECOGRAPHY
LIMITATIONS
Pitfalls/Drawbacks:
• No Bowel cleansing/preparation.
• Inability to evacuate/defecate during examination.
Bend knees if needed.
• Suceptibility artifacts.
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HASTE Cine (SSFSE)
• Implants
CONCLUSION
MR Defecography:
• Provides an accurate and comprehensive evaluation of the defecation
process.
• It is superior to fluoroscopic defecography, providing the ability to detect
associated abnormalities in the bladder and cervix/vagina.
• Defecation phase imaging yields important additional information on the
presence and degree of pelvic floor abnormalities.
• The exam is fast (approx. 30 minutes) and easily incorporates the
defecation phase in which 30% of abnormalities are missed.