MAGNETIC-RESONANCE VENOGRAPHY VERSUS CONTRAST VENOGRAPHY TO DIAGNOSE THROMBOSIS AFTER JOINT SURGERY

Magnetic resonance venography is a recently developed, noninvasive mea ns of visualizing the proximal veins of the lower extremity and pelvis , Magnetic resonance venography is compared with standard contrast ven ography in the diagnosis of proximal deep vein thrombosis after total joint arthroplasty. Two hundred seven extremities were evaluated in a blinded study 5 to 7 days after surgery, Standard contrast venography identified 11 proximal deep vein thromboses, Initial interpretations o f the magnetic resonance venographies by staff radiologists identified 5 of the proximal vein thromboses (sensitivity 45%), Two patients wit h negative standard contrast venographies were identified as positive (specificity 99%), A retrospective review of all magnetic resonance ve nographies by a dedicated magnetic resonance angiographer identified 1 0 of 11 deep vein thromboses seen on standard contrast venography (sen sitivity 91%), Both false negatives were identified as positives. Stan dard contrast venography remains the gold standard for identifying pro ximal vein thromboses, Emerging magnetic resonance imaging techniques have created a potential alternative modality by which to identify dee p vein thrombosis, The present study suggests that standard contrast v enography continues to be the most accurate modality currently availab le, Although magnetic resonance venography seems to be accurate, its i nterpretation requires experience. As costs diminish and experience in creases, magnetic resonance venography will have increased importance in the clinical recognition of deep vein thrombosis.