Lung Perfusion Measured With Dual-Energy CT in Patients With Chronic Thromboembolic Pulmonary Hypertension: Comparative Study With Right Heart Catheterization and V/Q

Lung Perfusion Measured With Dual-Energy CT (DECT) in Patients With Chronic Thromboembolic Pulmonary Hypertension (CTEPH): Comparative Study With Right Heart Catheterization and Ventilation/Perfusion Scintigraphy (V/Q)

A comparative, observational, cross-sectional and prolective diagnostic test study, including patients that have had a right heart catheterization and were referred for a CT pulmonary angiography as part of their imaging workup protocol for pulmonary hypertension.

Dual-energy computed tomography (DECT) pulmonary angiography was performed on each patient to obtain perfusion maps and do a quantitative analysis. Segments with and without perfusion defects according to significant differences in the quantitative values, were defined as compatible or not with chronic thromboembolism.

To assess the accuracy of the method and evaluate its performance, these results were compared with the sole results from the right heart catheterization, known to be the gold standard diagnostic tool.

a comparative, observational, cross-sectional and prolective diagnostic test study is conducted, including consecutive patients from the pulmonary hypertension clinic at our institution, from March 2017 to October 2018. Patients that have had a right heart catheterization and were referred for a CT pulmonary angiography as part of their imaging workup protocol. (The minimum sample size calculated is 26 patients).

DECT pulmonary angiography (256-slice and double-source CT scanner) was performed on each patient. Obtaining perfusion maps and doing a quantitative analysis by circular regions of interest (ROI) and iodine-related attenuation values (IRA) on each lung segment. Then, according to the finding in right heart catheterization, a comparison will be made between to groups: segments with and without perfusion defects, in order to find significant differences in the quantitative.

To assess the accuracy of the method and evaluate its performance, these results were later compared with the sole results from the right heart catheterization.

ROC curves were plotted to extract possible decision thresholds of the IRA values to classify perfusion as normal or deficient with this technique.

Inclusion Criteria:

• Patients from the pulmonary hypertension clinic at our institution who have had right heart catheterization and were referred for a pulmonary CT angiography as part of their imaging workup protocol.

Exclusion Criteria:

• creatinine > 1.5 mg/dL