Spiral CT in the diagnosis of pulmonary embolism.

ABSTRACT

Objective: To evaluate the usefulness of spiral computed tomography (CT) in the diagnosis of pulmonary embolism (PE). Methods: A retrospective study was performed on 52 patients who underwent CT angiography (CTA) using spiral CT at our department from May 2000 to August 2003. A thoracic radiologist who was blinded to the database reviewed the radiological findings in all examinations from clinical data. A final diagnosis of PE was made by clinical conclusion from all other investigations, laboratory results and treatment outcome. Results: From 52 cases recruited into the study, 24 cases were suspected of PE before the examinations. Sixteen cases resulted in a final diagnosis of PE with acute PE in 7 cases and chronic PE in nine. The CTA correctly diagnosed PE in eleven cases, two cases were false-negative; CTA was proven to indentify PE that were detected through conventional angiography. Seventeen lesions of intraluminal filling defects were found, two of which were main pulmonary arteries (PA), four lobar and eleven segmental PA. The CT findings of clots consisted of six complete filling defects, two central clots and nine eccentric clots. The other findings, such as intraluminal web, calcification of clots, enlarged vessels and irregular thickening of vessel walls, were also demonstrated. Ancillary findings found in this study were atelectasis, oligemia, mosaic pattern and pleural effusion. Conclusion: Spiral CT is a useful method for the diagnosis of PE.