Abstract No. 487 Role of time-resolved magnetic resonance angiography in appropriate diagnosis of patients with Klippel-Trenaunay syndrome

Abstract

Vascular malformations associated with genetic mutations are rare and patient presentation can be complex. Misdiagnosis in this patient population is not uncommon. Time-resolved magnetic resonance angiography (TR-MRA) provides essential information about flow dynamics of a malformation that aids in establishing the correct diagnosis and appropriate treatment planning. A retrospective chart review at one institution was performed after obtaining Institutional Review Board approval. The charts of patients previously diagnosed or suspected to have Klippel-Trenaunay syndrome (KTS) at the time of referral were analyzed to assess the value of TR-MRA in the patient’s diagnosis and treatment. TR-MRA delineates arterial and venous phases of vascular enhancement. TR-MRA involves rapid sequential T1-weighted imaging during the passage of the contrast bolus to document the first pass through the vasculature. This technique provides dynamic information that is not available with conventional single-phase MRA and was previously only available with diagnostic catheter angiography. Of 17 patients referred to IR clinic with a suspected diagnosis of KTS, TR-MRA was performed in 76% of the cases (11 performed at the treating institution and 2 performed at an outside hospital). TR-MRA provided an alternate diagnosis in 2 of 13 cases (15%). In one case, TR-MRA demonstrated an arteriovenous malformation (AVM) rather than a purely venous malformation, which in the presence of a port wine stain and limb hypertrophy is consistent with Parkes-Weber syndrome (PWS). The second case demonstrated no evidence of vascular malformation despite the presence of a port wine stain. In both cases, TR-MRA changed patient management. TR-MRA definitely identifies and differentiates fast-flow and slow-flow vascular malformations impacting patient diagnosis and management. In our study, time-resolved MRA confirmed the presumed diagnosis of KTS in 85% of patients, and revealed new information leading to change of diagnosis and management in 15% of patients initially referred with a presumed diagnosis of KTS.