Influences of primary graft disfunction (PGD) on parenchymal remodeling after lung transplantation (LT) detected by mean quantitative computed tomography (CT)

Regional analysis by CT could be an attractive technique to interpret lung patterns after LT. We evaluate the application of CT functional mask derived parameters to determine whether development of PGD is associated with short and/or long term postoperative evidences of pulmonary function alterations. 18 consecutive patients who underwent bilateral LT were recruited. Patients were evaluated at 24, 48 and 72 hours after LT to establish PGD occurrence and grading. Patients without evidence of PGD constituted the PGD0 Group; patients with grade 2 and/or 3 composed the PGD Group. CT scans at 3 and 12 months after LT were analyzed to measure specific gas volume (SVg) changes normalized on expiratory SVgEXP of the whole lung (ΔSVg/SVgEXP) and to obtain functional masks of density variation (ΔHU), namely maps of low ventilation (LV), consolidation (C), air trapping (AT) and healthy parenchyma (H). Our main result was the evidence of a marked decrease in ΔSVg/SVgEXP, both at 3 and 12 months after LT, indicating a high degree of ventilation defects. Higher grades of PGD were associated to higher percentages of LV while percentages of AT and C were negligible (fig). We demonstrate that quantification of ventilation defects by CT functional mask can offer insight into the correlation between PGD and pulmonary function after LT at short and mid-term.