Dual-energy CT perfusion and angiography in chronic thromboembolic pulmonary hypertension: diagnostic accuracy and concordance with radionuclide scintigraphy

Objectives To evaluate the diagnostic accuracy of dual-energy computed tomography (DECT) perfusion and angiography versus ventilation/perfusion (V/Q) scintigraphy in chronic thromboembolic pulmonary hypertension (CTEPH), and to assess the per-segment concordance rate of DECT and scintigraphy. Methods Forty consecutive patients with proven pulmonary hypertension underwent V/Q scintigraphy and DECT perfusion and angiography. Each imaging technique was assessed for the location of segmental defects. Diagnosis of CTEPH was established when at least one segmental perfusion defect was detected by scintigraphy. Diagnostic accuracy of DECT perfusion and angiography was assessed and compared with scintigraphy. In CTEPH patients, the per-segment concordance between scintigraphy and DECT perfusion/angiography was calculated. Results Fourteen patients were diagnosed with CTEPH and 26 with other aetiologies. DECT perfusion and angiography correctly identified all CTEPH patients with sensitivity/specificity values of 1/0.92 and 1/0.93, respectively. At a segmental level, DECT perfusion showed moderate agreement (kappa=0.44) with scintigraphy. Agreement between CT angiography and scintigraphy ranged from fair (kappa=0.31) to slight (kappa=0.09) depending on whether completely or partially occlusive patterns were considered, respectively. Conclusions Both DECT perfusion and angiography show satisfactory performance for the diagnosis of CTEPH. DECT perfusion is more accurate than angiography at identifying the segmental location of abnormalities. Key Points Chronic thromboembolic pulmonary hypertension (CTEPH) is potentially treatable by surgery. Dual-energy computed tomography (DECT) allows angiography and perfusion using a single acquisition. Both DECT perfusion and angiography showed satisfactory diagnostic performance in CTEPH. DECT perfusion was more accurate than angiography in identifying segmental abnormalities.