Diagnosis of chronic thromboembolic pulmonary hypertension: comparison of ventilation/perfusion scanning and multidetector computed tomography pulmonary angiography with pulmonary angiography.

OBJECTIVE: The correct and prompt diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) plays a pivotal role in determining appropriate therapy. This study aimed to compare the diagnostic efficacy of pulmonary ventilation/perfusion (V/Q) scanning and computed tomography pulmonary angiography (CTPA) using pulmonary angiography as the golden standard.

METHODS: A total of 114 consecutive patients (49 men and 65 women, age 43.3 ± 15.3 years) suspected of having CTEPH were prospectively enrolled. All patients underwent V/Q scanning, CTPA, and pulmonary angiography within an interval of 7 days from one another. Interpretation of V/Q images was based on the refined Pulmonary Embolism Diagnosis criteria. For threshold 1, high-probability and intermediate-probability V/Q scan findings were considered to be positive, and low-probability/normal V/Q scan findings were negative. For threshold 2, only a high-probability V/Q scan finding was considered to be positive, and intermediate-probability and low-probability/normal V/Q scan findings were considered to be negative.

RESULTS: Fifty-one patients (44.7%) had a final diagnosis of CTEPH. V/Q scan showed high probability, intermediate probability, and low probability/normal scan in 52, three, and 59 patients, respectively. CTPA revealed 50 patients with CTEPH and 64 patients without CTEPH. The sensitivity, specificity, and accuracy of the V/Q scan were 100, 93.7, and 96.5%, respectively, with threshold 1, and 96.1, 95.2, and 95.6%, respectively, with threshold 2; similarly, the sensitivity, specificity, and accuracy of CTPA were 92.2, 95.2, and 93.9%, respectively.

CONCLUSION: In conclusion, both V/Q scanning and CTPA are accurate methods for the detection of CTEPH with excellent diagnostic efficacy.