Relationship between Lung Volume and Pulmonary Function in Patients With Adolescent Idiopathic Scoliosis

Study Design: Retrospective. Objectives: We determined values for the volume of right lung (Vr), left lung (Vl), total lung volume (Vt), and left/right lung volume ratio (Vl/Vr), allowing comparison between those data measured and those of age-matched controls. To find whether lung volume correlates with preoperative pulmonary function. Summary of Background Data: To our knowledge, no study on relationship between computed tomographic (CT) scans determined lung volume and pulmonary function test (PFT) in scoliosis have been published. Methods: All examinations with PFT (31 cases) were identified. Three-dimensional volumetric reconstruction of lung parenchyma was performed on existing preoperative CT scans for 26 idiopathic scoliosis patients. Vl, Vr, Vt, Vl/Vr, and absolute value of right volume minus left volume (|Vr−Vl|) were calculated and correlated with PFTs. To determine if significant difference of preoperative lung volume exists between idiopathic scoliosis patients and controls. Linear regression models, using 3-dimensional lung volume parameters as predictors for vital capacity (VC), forced vital capacity (FVC), and total lung capacity (TLC), were created. Results: Vt was positively correlated with VC, FVC, forced expiratory volume in 1 second (FEV1), TLC, predicted value for FVC (FVC%), predicted value for FEV1 (FEV1%), predicted value for TLC (TLC%), and predicted value for maximal ventilator volume (MVV%) ( P <0.05); |Vr−Vl| was not correlated with ventilation parameters ( P >0.05); Diffusion parameters were not correlated with CT-reconstructed lung volume parameters ( P >0.05); male and female adolescent idiopathic scoliosis patients had less Vt, Vr, and Vl compared with those of age-matched controls ( P <0.05). Conclusions: Vt was positively correlated with VC, FVC, FEV1, TLC, FVC%, FEV1%, TLC%, and MVV%. Vt, Vr, and Vl of adolescent idiopathic scoliosis patients were less than those of age-matched controls.