Pelvic Floor Dysfunction: The Role of Transperineal/Translabial Ultrasound in Diagnosis

Introduction to Pelvic Floor Dysfunction

Pelvic floor dysfunction (PFD) encompasses a range of disorders resulting from impaired function or structure of the pelvic floor muscles, ligaments, and connective tissues that support the bladder, rectum, and reproductive organs (uterus or prostate). Common conditions include urinary incontinence (UI), pelvic organ prolapse (POP), fecal incontinence (FI), defecatory dysfunction, chronic pelvic pain, and sexual dysfunction. PFD prevalence is substantial, particularly among women. In the United States, approximately 23.7% of women experience at least one symptomatic pelvic floor disorder, with urinary incontinence affecting 15.7%, fecal incontinence 9.4%, and pelvic organ prolapse 2.9%. Globally, rates can be higher, with studies from regions like Ethiopia reporting 45.8% prevalence among women. Risk factors include childbirth, menopause, obesity, chronic constipation, heavy lifting, and aging, with nearly 50% of postpartum women developing PFD within a decade.

Main Symptoms and Reasons for Underdiagnosis

Main Symptoms of Pelvic Floor Dysfunction

Symptoms of PFD vary depending on the affected compartment but often overlap and can severely impact daily activities and quality of life.

-Urinary Issues: Leaking urine during coughing, sneezing, laughing, running, or exercising (stress incontinence); urgent or frequent need to urinate; pain during urination; difficulty starting urination; incomplete bladder emptying; recurrent urinary tract infections.

-Bowel Issues: Constipation or straining during bowel movements; incomplete evacuation; fecal incontinence or difficulty controlling gas; passing wind involuntarily; obstructed defecation; frequent bowel movements (up to 10-30 times a day).

-Pelvic Organ Prolapse Symptoms: Sensation of heaviness, fullness, pulling, or aching in the pelvis or vagina; seeing or feeling a bulge at the vaginal opening; lower back pain.

-Pain and Discomfort: Chronic pelvic or perineal pain, often worse with sitting; pain in the lower abdomen, groin, or rectum; muscle spasms; unexplained low back pain.

-Sexual Dysfunction: Pain during intercourse (dyspareunia); difficulty inserting or retaining tampons; reduced sensation in the vagina.

-Other: Involuntary passing of wind; pressure in the rectum; perineal descent; trouble reaching the toilet in time; leaking urine while sleeping; tampons dislodging or falling out.

These symptoms may worsen with activities like heavy lifting or straining and can progress if untreated.

Reasons for Underdiagnosis

Despite its high prevalence, PFD is frequently underdiagnosed, affecting up to 50% of childbearing women and occurring in as many as 1 in 10 people overall.

-Embarrassment and Stigma: Patients often hesitate to report sensitive symptoms like incontinence or sexual issues due to embarrassment.

-Symptom Overlap and Misdiagnosis: Symptoms are commonly mistaken for other conditions, such as irritable bowel syndrome, endometriosis, pelvic inflammatory disease, ovarian issues, uterine fibroids, or simply aging.

-Broad and Multifactorial Nature: PFD involves multiple systems (urologic, gynecologic, colorectal), requiring a multidisciplinary approach that is not always pursued.

-Lack of Awareness and Screening: Limited education among patients and providers leads to inadequate routine screening; it's often overlooked in men and thought of only as incontinence.

-Complex Diagnostic Process: No single test confirms PFD; symptoms may be attributed to lifestyle factors like diet or stress, delaying comprehensive evaluation.

-Associated Factors: Co-existing disorders, emotional contributors like anxiety, and underrecognition in primary care contribute to missed diagnoses.

Addressing these barriers through increased awareness and screening can improve early detection and management.

Diagnostic Challenges in Pelvic Floor Dysfunction

Diagnosing PFD is complex due to overlapping symptoms with other urological, gynecological, or gastrointestinal conditions. Clinical evaluation relies on history-taking, physical exams, and tools like the Pelvic Organ Prolapse Quantification (POP-Q) system. However, these methods may not capture dynamic dysfunction, such as muscle coordination during straining or relaxation.

Imaging modalities like magnetic resonance imaging (MRI), computed tomography (CT), and defecography have traditionally been used. MRI provides detailed anatomical views but is costly and less effective for dynamic assessment in supine positions. CT involves radiation exposure, and defecography, while dynamic, is invasive, uncomfortable, and also exposes patients to radiation. Misdiagnosis is common when relying solely on clinical exams, as symptoms like pelvic pain may be confused with conditions like endometriosis or interstitial cystitis.

The Role of Transperineal/Translabial Ultrasound in Diagnosis

Transperineal ultrasound (TPUS) or translabial ultrasound (TLUS) is a non-invasive imaging technique that uses a high-frequency convex probe (typically 3.5–7 MHz) placed externally on the perineum or labia to visualize the pelvic floor. Unlike transvaginal ultrasound (TVUS), which involves internal probe insertion and is primarily used for gynecological assessments, TPUS/TLUS is ideal for dynamic evaluation of pelvic floor function during maneuvers like Valsalva, coughing, or pelvic floor muscle contraction. It provides real-time imaging of the anterior (bladder, urethra), middle (vagina, uterus), and posterior (rectum, anus) compartments.

TPUS/TLUS can assess:

-Bladder neck mobility and urethral hypermobility in stress urinary incontinence.

-Pelvic organ prolapse, including cystocele, rectocele, and enterocele.

-Levator ani muscle integrity, identifying avulsions or defects from childbirth.

-Anorectal function, detecting abnormalities like anismus or rectal prolapse.

-Postoperative outcomes, such as mesh implant complications (e.g., erosion).

Three-dimensional (3D) and four-dimensional (4D) TPUS/TLUS enhance diagnostic precision by providing volumetric data and real-time functional views, improving prognosis for conditions like POP or UI. TPUS/TLUS also supports biofeedback therapy, allowing patients to visualize pelvic muscle contractions for rehabilitation.

Problems in Diagnosis: Lack of Training and No Specific CPT Code

Lack of Training

TPUS/TLUS is highly operator-dependent, requiring specialized skills in probe positioning, image acquisition, and interpretation of dynamic findings. However, training programs for pelvic floor ultrasound are limited, particularly for physiotherapists and non-radiologist clinicians. Inconsistent training leads to variability in diagnostic accuracy, with risks of over- or under-diagnosing conditions like prolapse or muscle defects. While professional organizations are developing guidelines, standardized curricula are not yet widely implemented, limiting the modality’s adoption.

Absence of a Specific CPT Code

There is no dedicated Current Procedural Terminology (CPT) code for TPUS/TLUS. It is often billed under general pelvic ultrasound codes, such as:

-76856: Complete pelvic ultrasound.

-76857: Limited pelvic ultrasound.

-76830: Transvaginal ultrasound, non-obstetrical (inappropriately applied to TPUS/TLUS).

These codes do not reflect the specialized, dynamic nature of TPUS/TLUS, which evaluates multiple compartments and functional states. This leads to reimbursement challenges, as insurers may deny claims or consider TPUS/TLUS integral to a standard pelvic exam. The lack of a specific code also hinders research, standardization, and broader clinical integration.

Advantages of Transperineal/Translabial Ultrasound Over Other Diagnostic Modalities

TPUS/TLUS offers significant advantages over MRI, CT, and defecography, making it a preferred modality for PFD diagnosis.

MRI: Expensive; long scan times; contraindicated for claustrophobia or metal implants; limited dynamic assessment in supine position.

CT: Radiation exposure; higher cost; limited functional assessment; less soft-tissue detail.

Defecography: Radiation; invasive (rectal contrast); patient discomfort; may miss subtle defects like enterocele.

Additional benefits include:

• Accessibility: TPUS/TLUS can be performed with portable ultrasound devices, suitable for point-of-care settings.

• Patient Comfort: External probe placement is less invasive than transvaginal ultrasound or defecography.

• Versatility: Effective for screening, postoperative evaluation, and guiding conservative treatments like pelvic floor muscle training.

• Cost-Effectiveness: Reduces reliance on expensive imaging, improving access in low-resource settings.

Compared to transvaginal ultrasound, TPUS/TLUS is better suited for dynamic functional assessment, as TVUS restricts movement during maneuvers and may distort anatomy due to probe pressure. TPUS/TLUS also avoids the discomfort of internal probes, enhancing patient compliance.

August 2025