Ventilation/perfusion SPECT/CT in patients with severe and rigid scoliosis: An evaluation by relationship to spinal deformity and lung function

Objective: Structural changes of the spine and chest wall associated with SRS result in poor cardiopulmonary function. Comprehensive assessment of pulmonary function is extremely important for patients with SRS before a correction operation. We explore the changes of distribution of lung ventilation and perfusion function in patients with SRS using SPECT/CT and describe the relation between these changes with Cobb angle and FVC%. Patients and methods: From March 2015 to August 2016, 16 consecutive SRS patients with a mean age of 20.1 years(range 11-36 years) were included in the study. Scoliotic parameters on radiographs were analyzed. FVC% were obtained by spirometry test. Lungs ventilation/perfusion single photon emission computed tomography scans was performed preoperatively in all patients to explore pulmonary ventilation and perfusion function changes. These changes were measured as the deviation form the normal perfusion and ventilation function distribution in right and left lung and correlated with the Cobb angle of main curve and FVC%. Results: The regional lung ventilation and perfusion function defects were not found in all SRS patients. Ventilation function deviation was a mean 5.7%(range, - 3.6% to 10.1%), significantly less than perfusion function deviation of 8.2%(range, - 0.3% to 22.2%) (P = 0.015, t = - 2.732). Lung ventilation and/or perfusion function deviation did not correlated with Cobb angle and FVC%, respectively. There was significant correlation between lungs ventilation and perfusion function deviation(P = 0.001, r = 0.753). Conclusion: The ventilation and perfusion function distribution were favourable in convex and concave side lung of SRS. Deformity bring about greater lungs perfusion function changes than ventilation function. The measurement of lung ventilation and perfusion function changes may represents an additional functional feature to assess pulmonary function of SRS more comprehensively.