What organs can be visualized on a sacral Magnetic Resonance Imaging (MRI)?

From the Guidelines

A sacral Magnetic Resonance Imaging (MRI) can visualize several important anatomical structures, including pelvic organs such as the bladder, urethra, and urethral ligaments, as well as the pelvic floor musculature and morphology. When considering the visualization of organs on a sacral MRI, it is essential to understand the capabilities and limitations of this imaging modality.

• The inherent high soft-tissue contrast resolution of MRI allows for anatomic evaluation of the pelvic organs, including the bladder and urethra, as well as urethral ligaments 1.
• MRI of the pelvis can demonstrate differences in pelvic floor musculature and bladder-neck morphology and urethrovesical angle when comparing patients with various conditions, such as stress urinary incontinence (SUI), mixed urinary incontinence (UI), and continence 1.
• Additionally, portions of other pelvic organs may be visible depending on the field of view, including the rectum, lower portions of the sigmoid colon, posterior aspects of the bladder, and in females, the posterior uterus and vagina, and in males, the prostate and seminal vesicles.
• The sacral MRI is particularly valuable for evaluating conditions such as sacral fractures, sacroiliitis, sacral insufficiency fractures, tarlov cysts, perineural cysts, sacral tumors (primary or metastatic), and sacral nerve compression syndromes, providing excellent soft tissue contrast that allows differentiation between normal anatomy and pathological processes, making it superior to CT scans for evaluating neural structures and soft tissue abnormalities in this region.
• The use of MRI pelvis without defecation or straining for functional evaluation of urinary dysfunction is not well-established; however, pelvic floor MRI allows for anatomic assessment of the pelvic floor, including location of urethrovesical junction, and assessment of urethral angle at rest 1.

From the Research

Organs Visible on Sacral MRI

The following organs can be visualized on a sacral Magnetic Resonance Imaging (MRI):

• Uterus 2, 3, 4
• Ovary 2, 3, 4
• Prostate gland 2, 4
• Rectum 5
• Sacrum 5, 6
• Pelvic musculature 6
• Urethra 4
• Vagina/Vulva 4
• Cervix 4

Additional Structures

Other structures that can be identified on a sacral MRI include:

• Fat, fluid, and calcification 3
• Lipid, hemorrhage, smooth muscle, fibrosis, solid malignant tissue, and hydrated soft tissue 3
• Congenital anomalies, such as imperforate anus 6
• Tethered cord, lipoma of the filum terminale, and renal dysplasia 6