PULMONARY THROMBOEMBOLISM - RECENT DEVELOPMENTS IN DIAGNOSIS WITH CT AND MR-IMAGING

Recent technical advances in computed tomography (CT; helical and elec tron beam) and magnetic resonance (MR) imaging have spurred a renewed interest in these modalities for the diagnosis of acute and chronic pu lmonary embolism (PE). These techniques can enable accurate clot detec tion down to segmental pulmonary arteries, with CT currently allowing more accuracy than that with MR imaging. Ongoing technical advances, p articularly in MR angiography, will likely increase diagnostic accurac y. Inability to reliably detect subsegmental acute emboli may not prov e to be a clinically significant limitation if lung imaging is coupled with evaluation for deep venous thrombosis. MR imaging can potentiall y accomplish this within a single examination. Incorporation of CT and MR imaging into diagnostic algorithms for suspected PE can be cost-ef fective. Evaluation of these new modalities should be based on patient outcome, not solely on clot detectability. Well-designed clinical tri als are warranted before CT and MR imaging can be used routinely in th e diagnosis of acute PE.