Table 2.

Summary of diagnostic criteria for CTEPH

Criteria	Pathologic findings	CT findings
Primary (87)
Changes in pulmonary arteries:	Organizing thrombus	Eccentric wall-adherent filling defect which may calcify (calcification in ≤10%) Stenosis or obstruction Post-stenotic dilatation
Changes due to PH:	Intravascular webs (due to recanalization)	Linear intraluminal filling defects
	Dilatation and atherosclerotic changes (due to increased pressure and turbulent flow)	Dilatation of PA (29 mm in men and 27 mm in women) and/or atherosclerotic calcification of PA (92) RV hypertrophy/dilatation Tortuous vessels Systemic collateral arterial supply: e.g., bronchial arterial collaterals towards pulmonary post-obstructive vessels Pericardial fluid (109)
Secondary (85)	Small-vessel arteriopathy due to shear stress, pressure, inflammation, and the release of cytokines	Mosaic lung perfusion (due to decreased perfusion) and variation in the size of segmental vessels

References (85, 87, 92, 109) were used in preparing this table.

CTEPH, chronic thromboembolic pulmonary hypertension; CT, computed tomography; PH, pulmonary hypertension; PA, pulmonary artery; RV, right ventricular.