Computed Tomography (CT) Imaging

CT imaging is a widely available and useful modality to reveal direct and indirect signs of CTEPH.^1,2 It has a role in diagnosis, operability assessment, and disease monitoring.^1,2

CT provides detailed views of the lung parenchyma and facilitates the diagnosis of interstitial lung disease, pulmonary veno-occlusive disease, and emphysema, if these are in the differential diagnosis.¹ CT can provide information about infarcts, vascular and pericardial malformations, and thoracic wall deformities.¹

Contrast-enhanced multidetector CTPA has become an established imaging modality for confirming CTEPH following a ventilation/perfusion (V/Q) scan.¹ The examination protocol involves a high-speed scan conducted during the pulmonary arterial phase.
Once CTEPH is confirmed, CTPA can be used to help determine the proximal extent of the thromboembolic material and therefore assess operability.²

Direct signs of CTEPH are organized emboli, partial filling defects or complete obstruction of pulmonary arteries, and bands and webs. Indirect signs include a mosaic pattern of the lung parenchyma, and the presence of dilated bronchial arteries.^1,3
CTPA may also help to identify complications of CTEPH such as pulmonary artery dilatation resulting in left main coronary artery compression and hypertrophied bronchial arterial collaterals, which may lead to hemoptysis.¹