Comparison of Lung Scintigraphy With Multi-Slice Spiral Computed Tomography in the Diagnosis of Pulmonary Embolism

PURPOSE To compare the diagnostic efficacy of lung perfusion scans combined with ventilation (V/Q) scans and/or chest radiography (CR) with contrast-enhanced multislice spiral CT pulmonary angiography (CTPA) in diagnosing pulmonary embolism (PE). MATERIALS AND METHODS Eighty-two consecutive patients with suspected PE underwent CTPA, lung perfusion scan, and CR. Of them, 28 patients underwent V/Q scans. The final diagnosis was made using a composite reference test. RESULTS The overall sensitivity and specificity were 89.2% and 92.1% for V/Q scan or perfusion scan combined with CR, and 97.3% and 97.4% for CTPA. For the 28 patients with V/Q scan, the sensitivity and specificity were 91.7% and 92.9% for V/Q scan, and 91.7% and 100.0% for CTPA. The segmental agreement rate between perfusion scan and CTPA was 69.5% (kappa = 0.30, P < 0.05). The perfusion scan revealed significantly more subsegmental abnormalities than CTPA (59 vs. 10, chi2 test, P < 0.05). CONCLUSIONS V/Q scan, perfusion scan combined with CR and CTPA all show high efficacy in diagnosing PE. V/Q scan or perfusion scan combined with CR is as accurate as CTPA.