The new technique of Hydro-CT based on thin slice and spiral methodology, including pharmacological intestinal paralysis and water distension, results in a high tumor detection rate and increases sensitivity and specificity of tumor differential diagnosis and of assessment of resectability.

We describe a patient with May-Thurner syndrome who underwent operative transection and transposition of the right common iliac artery without direct venous repair, because preoperative and intraoperative intravascular ultrasound scans were negative for "spurs" in the left common iliac vein. When symptoms and signs persisted, a postoperative magnetic resonance venogram (MRV) showed severe stenosis in the left common iliac vein. Progressive, but incomplete, clinical improvement occurred with conservative management.

The new technique of hydrosonography combines the value of routine non-invasive abdominal ultrasound with increased sensitivity and specificity for tumor detection and assessment of resectability by improved imaging accuracy.