Identification of target zones for lung volume reduction surgery using three-dimensional computed tomography rendering

Background: The key issues for performing lung volume reduction surgery (LVRS) is the identification of the target zones. Recently introduced three-dimensional computed tomography rendering methods are used to identify the morphological distribution and its severity of lung emphysema by densitometry. We demonstrate a new software for emphysema imaging and show the pre- and post-operative results in patients undergoing LVRS planned based on this new technology. Methods: A real-time three-dimensional image analysis software system was used pre- and 3 months post-operatively in five patients with heterogeneous emphysema and a single patient with homogeneous morphology scheduled for LVRS. Focus was on low attenuation areas with <950 HU, distribution on both lungs and the value of the three-dimensional images for planning surgery. Functional outcome was assessed by pulmonary function tests after 3 months. Results: Five patients underwent bilateral LVRS and one patient had unilateral LVRS. All patients showed a median increase in forced expiratory volume in 1 s of 70% (range 30-120%), compared with baseline values. Hyperinflation (expressed as residual volume/total lung capacity ratio) was reduced by 30% (range 5-32%). In the patients with heterogeneous emphysema, the pre- and post-operative computed tomography scans and the densitometries showed a decrease in low attenuation areas by 23% (right side) and by 17% (left side), respectively. Conclusion: We demonstrate three-dimensional computed tomography-rendered images for planning personalised remodelling of hyperinflated lungs using LVRS. This user-friendly software has the potential to assist surgeons and interventional pulmonologists to select patients and to visualise target areas in LVRS procedures.