Imaging collateral ventilation in patients with advanced Chronic Obstructive Pulmonary Disease – relative sensitivity of 3He and 129Xe MRI

The success of lung volume reduction with endobronchial valves in patients with Chronic Obstructive Pulmonary Disease (COPD) depends on the absence of collateral ventilation into the target lung segment. Collateral ventilation can be assessed using time-resolved ³He MRI, but providing this clinical application with ¹²⁹Xe MRI would be desirable. Two patients with severe COPD were scanned with time-resolved ³He and ¹²⁹Xe MRI. In both patients, collateral ventilation visualised using ³He MRI was not observed with ¹²⁹Xe MRI. Although the small sample size is a limitation, this suggests that ¹²⁹Xe MRI may not be suitable for the assessment of collateral ventilation.