Klippel–Trénaunay syndrome (KTS) is a well-known eponym for a capillary-lymphatic-venous malformation which is associated with soft tissue and skeletal hypertrophy, usually of one or more limbs. Plain films, sonograms, conventional venograms, and arteriograms have been employed for the evaluation of the disease.

To demonstrate the usefulness of multidetector computed tomography (MDCT) and fast 3-dimensional magnetic resonance imaging (3D-MR) venography for the assessment and therapeutic planning of patients with KTS.

A prospective study in 16 consecutive patients with KTS using MDCT and 3D-MR venography, performed between January 2004 and January 2006 in a university hospital in Pamplona, Spain.

In nearly all patients, persistent embryologic veins were observed, and in one subject aplasia/atresia of the whole deep venous system of the affected extremity was seen. In four individuals hypoplasia of the femoral vein was observed; one subject had duplication of the femoral vein, and in three patients aplasia/atresia of this vein was found. Only half of the patients had normal popliteal veins. In one patient, aneurysmal dilatation of the popliteal vein was detected, and in six subjects, aplasia of this vein was observed. The presence of geographic stains was suggestive of hypoplasia and/or aplasia of femoral and popliteal veins.

The small size of the group of patients with KTS, which is related to low incidence of the disease.

MDCT and 3D-MR venography are extremely helpful for the global evaluation of patients with KTS. Information regarding soft tissue and bony anatomy as well as information about superficial and deep venous systems may be obtained with a single exam.