Ventilation perfusion scans allow the distinction to be made between primary pulmonary hypertension and obstructive causes of pulmonary hypertension such as CTEPH. When V/Q scan results are inconclusive, or in cases where information about the technical operability is required, pulmonary arteriography is the procedure of choice.

Ventilation perfusion (V/Q) scans and pulmonary arteriograms are advocated as providing the most useful information in the diagnosis of, and subsequent decisions about, the operability of cases of CTEPH.