Pulmonary Hypertension: Clinical Classification Updates, Pathology, and Multimodality Imaging Evaluation

Pulmonary hypertension (PH) is a progressive disease associated with high morbidity and mortality. PH is classified into five groups based on underlying pathophysiology and etiology: pulmonary arterial hypertension (group 1); PH due to left heart disease (group 2); PH secondary to lung disease (group 3); pulmonary artery obstruction, including chronic thromboembolic pulmonary hypertension (CTEPH) (group 4); and PH due to unclear or multifactorial mechanisms (group 5). Radiologists play a major role in the multidisciplinary evaluation of patients with PH alongside specialists in pathology, pulmonary medicine, and cardiology. Given the widespread use of CT, imaging may be the first modality to suggest PH and plays a central role in the diagnosis and management of CTEPH. This review describes the pathophysiology of the five PH groups and emphasizes imaging findings that raise suspicion for PH. Discussion includes the roles of CT and MRI in PH evaluation, risk stratification, and assessment of treatment response, as well as the current applications of multienergy CT, echocardiography, and cardiac MRI in PH management. Keywords: CT Angiography, CT-Dual Energy, CT, MR Imaging, Pulmonary Arteries, Pulmonary, Echocardiography, Thorax, Vascular, Pathology, Pulmonary Hypertension, Chronic Thromboembolic Disease, Chronic Thromboembolic Pulmonary Hypertension, Pulmonary Embolism, Pulmonary Arterial Hypertension, Pulmonary Venoocclusive Disease, Pulmonary Capillary Hemangiomatosis, Pulmonary Hypertension Groups, Dual-Energy CT, Photon-counting CT, Spectral CT © RSNA, 2026.