New Modalities for the Diagnosis of Deep Venous Thrombosis and Pulmonary Embolism

Abstract

In Brief Venous thromboembolic disease is a serious, but treatable disease, the timely diagnosis of which requires a high level of clinical suspicion. Despite advances in medical technology, pulmonary embolism still manages to evade detection in clinical practice. Deep vein thrombosis (DVT) can be reliably diagnosed with compression ultrasound, although repeat testing several days after a negative test rules out clinically significant DVT most accurately. Because the signs and symptoms of pulmonary embolism (PE) are nonspecific, the diagnosis may be missed if other coexisting conditions are present and presumed to be responsible for the clinical findings. Ventilation/perfusion (VQ) scanning remains an appropriate initial test in patients without underlying ventilation abnormalities seen on chest radiographs. Spiral computerized tomography (CT) can be a useful alternative or an adjunctive diagnostic tool for patients with suspected PE and equivocal VQ scans. Patients with poor cardiopulmonary reserve may need a more aggressive diagnostic approach, given the tendency of spiral CT to miss subsegmental emboli, which may be of great consequence to this group of patients. Pulmonary angiography should be used to confirm the diagnosis in patients with equivocal noninvasive tests and a high pretest probability. A negative d-dimer in the setting of a low pretest probability carries a high negative predictive value. Clinical algorithms based on pretest probability and d-dimer testing are promising methods to decrease the need for imaging in the outpatient setting. Although most cases of pulmonary embolism and deep vein thrombosis respond well to treatment, the timely diagnosis of these disorders remains a major impediment. This article describes the clinically available technology for diagnosis of thromboembolism, and reviews the evidence supporting a rational approach to their use.