How Is Pelvic Congestion Syndrome Diagnosed?

• What it is: This specialist ultrasound is widely endorsed by pelvic venous specialists as the preferred first-line non-invasive investigation for PCS. It is meaningfully different from a standard pelvic ultrasound. Using Doppler technology, it assesses both the structure of the pelvic veins and, critically, the direction and velocity of blood flow within them. Where further confirmation is required, catheter venography remains the reference standard for definitive diagnosis.
• The scan evaluates: the ovarian veins (left and right) for dilation and retrograde flow; the internal iliac veins and pelvic venous plexus; the left renal vein (for Nutcracker Syndrome); and the pelvic organs, to identify or exclude other conditions such as fibroids or ovarian cysts that may mimic or coexist with PCS.
• Why it may differ from scans you have had before: The scan is conducted using a specific protocol developed for PCS assessment. It may include a Valsalva manoeuvre — you will be asked to bear down gently, increasing abdominal pressure — to provoke retrograde flow that may not be visible at rest. The scan may be performed with you partially upright or tilted, rather than lying completely flat.
• What to expect: The scan involves two components: a trans-abdominal scan (the probe is placed on your abdomen, as with a routine ultrasound), followed by a transvaginal component (a small probe is gently placed internally). The transvaginal component allows clearer visualisation of the pelvic veins and organs. The procedure is typically performed in an outpatient setting. You will be asked to empty your bladder before the transvaginal portion. Discomfort, if any, is generally mild and brief.

• What it is: This assessment evaluates the function of the pelvic floor muscles and identifies specific sites where venous blood may be leaking from the pelvis into the groin or legs. The pelvic floor and pelvic venous system are closely related anatomically and often affect one another — pelvic floor dysfunction and pelvic venous congestion frequently co-exist.
• Why it matters: Understanding both allows the care team to plan management that addresses all contributing factors, not only the venous anatomy. This assessment also informs the physiotherapy component of care.

• What it is: In some patients, pelvic venous reflux does not remain confined to the pelvis. Blood leaking backwards through pelvic veins can travel into the veins of the legs and groin, presenting as varicose veins — particularly in the inner thighs, back of the thighs, vulval area, or buttocks. These are sometimes called atypical varicose veins because they arise from a pelvic, rather than a leg, venous source.
• What the scan does: The venous incompetency duplex maps the path of these abnormal veins from their pelvic origin into the lower limbs. This information is important for treatment planning, as leg varicose veins that arise from a pelvic source require a different approach from standard leg varicose vein treatment.

• What it is: Postural Orthostatic Tachycardia Syndrome (POTS) is a condition of the autonomic nervous system in which blood pressure and heart rate do not regulate normally when moving from lying to standing. It produces symptoms including light-headedness, rapid heartbeat, brain fog, easy fatigue, abdominal bloating, and leg swelling.
• Why it is relevant to PCS: Many women with PCS are also found to have features of POTS, and vice versa. Emerging evidence suggests that abnormal venous pooling may contribute to the circulatory instability seen in POTS when upright, though the precise relationship between the two conditions remains an active area of research. Identifying POTS alongside PCS is clinically important because it changes the scope of management.
• What the test involves: You will lie on a motorised table that is then tilted to bring you to a near-upright position. Your heart rate and blood pressure are monitored throughout. The test identifies whether symptoms of autonomic instability are triggered by the postural change.

When further imaging is considered, for some patients, the duplex ultrasound assessment provides sufficient information to proceed with management planning. For others — particularly where anatomy is complex, where a compression syndrome such as Nutcracker Syndrome or May-Thurner Syndrome is suspected, or where a procedural intervention is being planned — additional imaging is indicated.

• CT Venography: CT venography uses computed tomography with an injected contrast agent to produce detailed cross-sectional images of the pelvic venous anatomy. It is particularly useful for mapping the extent of dilated veins, identifying anatomical compression variants, and assessing collateral vessels. It involves exposure to ionising radiation and an iodine-based contrast agent. Kidney function is typically checked before the scan, as the contrast agent is cleared through the kidneys.
• MR Venography: Magnetic resonance venography achieves similar anatomical mapping without ionising radiation. It is particularly useful for assessing soft tissue structures alongside the vascular anatomy and for evaluating pelvic organs in detail. It requires the injection of a gadolinium-based contrast agent. Patients with significantly impaired kidney function require specific consideration before gadolinium is used.
• Catheter Venography — The Reference Standard: Catheter venography is the established reference standard for definitive assessment of pelvic venous reflux. A thin, flexible catheter is guided through a small puncture site — typically in the neck or groin — into the pelvic veins under real-time X-ray guidance. Contrast dye is injected directly into the veins, allowing the specialist to observe blood flow patterns directly, measure vein diameters against established diagnostic thresholds, and confirm whether venous reflux meets the criteria for PCS.

The procedure is performed under local anaesthesia with light sedation. Most patients describe a feeling of pressure rather than pain. A small bruise or tenderness at the puncture site is common and typically resolves within a few days.

In some cases, if the diagnosis is confirmed during catheter venography, the specialist may proceed to embolisation treatment in the same session. This decision is always discussed with the patient in advance. The diagnostic and treatment steps are distinct, even when they occur during the same procedure. Where this is a possibility, it will be explained clearly before you consent.