What is the best imaging modality to confirm a diagnosis of cystocele (a type of pelvic organ prolapse) in a woman with urinary incontinence and an outpouching in the anterior vaginal wall?

From the Guidelines

For a patient with urinary incontinence and an outpouching in the anterior vaginal wall, the best imaging modality to confirm a diagnosis of cystocele is MR defecography, as it allows for comprehensive anatomic and functional evaluation of the entire pelvic floor, including the bladder and urethra, and has been shown to have high agreement with physical examination for prolapse in the anterior compartment 1.

Key Points to Consider

• MR defecography is a specialized type of dynamic MRI of the pelvic floor that is typically performed with rectal contrast but without IV contrast and includes MRI acquisition during active defecation of rectal contrast 1.
• The inherent high soft-tissue contrast resolution of MRI allows for assessment of the pelvic organs, including the bladder and urethra, as well as the urethral ligaments 1.
• MR defecography has moderate correlation with surgical findings for diagnosis of full-thickness rectal prolapse, internal rectal prolapse, posterior colopocele, rectocele, and peritoneocele, and is beneficial in detecting or differentiating cases of enteroceles in apical or posterior compartment prolapse 1.
• Static high-resolution T2-weighted images performed as part of a routine MR defecography may be used for anatomic evaluation and can detect and quantify levator muscle defects in patients with prolapse 1.

Benefits of MR Defecography

• Allows for comprehensive anatomic and functional evaluation of the entire pelvic floor
• High agreement with physical examination for prolapse in the anterior compartment
• Can detect and quantify levator muscle defects in patients with prolapse
• Beneficial in detecting or differentiating cases of enteroceles in apical or posterior compartment prolapse

Limitations of Other Imaging Modalities

• Other imaging modalities, such as CT and ultrasound, may not provide the same level of detail and comprehensive evaluation of the pelvic floor as MR defecography 1.
• While physical examination is an important part of the initial evaluation, imaging may be necessary to confirm clinically suspected prolapse, assess the severity of prolapse, and evaluate for associated structural defects or functional abnormalities 1.

From the Research

Imaging Modalities for Cystocele Diagnosis

To confirm a diagnosis of cystocele, a type of pelvic organ prolapse, in a woman with urinary incontinence and an outpouching in the anterior vaginal wall, the following imaging modalities can be considered:

• Magnetic Resonance Imaging (MRI): Highly sensitive and specific for the diagnosis of urethral diverticulum 2, and can depict pelvic floor anatomy as well as organ prolapse 3, 4
• Computed Tomography (CT): Can demonstrate prolapse in patients who cannot tolerate MRI, and may be useful as an alternative diagnostic tool 3
• Sonography: May be the first line investigation for urethral diverticulum, although MRI is more sensitive and specific 2

Key Findings

Key findings from the studies include:

• MRI can evaluate the curvature of the urethral-vaginal interface in women with and without stress urinary incontinence 5
• The radius of the urethral-vaginal interface curvature was smaller in subjects with anterior vaginal wall prolapse beyond 2 cm proximal to the hymen 5
• MRI can predict and study patients with and at risk for pelvic organ prolapse using novel measures such as anterior pelvic area and levator volumes 4

Diagnostic Considerations

When considering a diagnosis of cystocele, the following should be taken into account:

• Clinical evaluation, including history and physical examination, is essential for diagnosing pelvic organ prolapse 6
• Additional testing, such as imaging studies, may be indicated for evaluation of bowel and bladder symptoms 6
• MRI is a valuable tool for evaluating pelvic floor disorders, including pelvic organ prolapse, rectal prolapse, and defecatory dysfunction 4