Visual assessment of functional lungs parenchyma on HRCT and 3He-MRI in patients after single lung transplantation: comparison with quantitative volumetric results

Purpose: Visual assessment of the ventilation using HRCT and 3He-MRI in patients after single lung transplantation (SLTX). Analysis of specific ventilation defects found with 3He-MRI and morphological changes found with HRCT. Materials and Methods: We evaluated 8 male patients (54±6 years) suffering from emphysema and six patients (3 males and 3 females, 58±9.5 years) suffering from idiopathic pulmonary fibrosis (IPF) after SLTX. The morphological changes at HRCT were classified and localized. In 3He-MRI (2D FLASH), 10 to 14 slices (slice thickness 10 mm, gap 5 mm) were acquired in coronal orientation to cover the whole lung. Ventilation defects were localized and characterized. The visually estimated ventilation was recorded on a 5-point scoring system. A double threshold technique was applied to volumetric quantification in 3He-MRI to serve as internal reference. Results: We found no correlation between morphological changes in HRCT and ventilation defects in 3He-MRI. The visual assessment of ventilation in 3He-MRI was sufficient in patients with emphysema, but this was not confirmed in patients with IPF. The visual assessment in HRCT did not correlate with the volumetric evaluation in both conditions. Conclusion: The various ventilation defects were not linked to specific morphological changes. For the visually assessed ventilation in patients with emphysema, 3He-MRI is superior to HRCT. (orig.)