Three-Dimensional Modeling of Lung Volumes in Application to Scoliosis

Adolescent idiopathic scoliosis is a curvature of the spine, which also distorts the ribcage and can lead to partial loss of lung function. In order to determine which of two surgical interventions to use on their patients - one temporary, one permanent - physicians must know the condition of their patients’ lung development. This is determined by measuring lung volume using CT scans which have negative radiation effects on children. Thus, this Capstone paper presents two major steps towards developing a novel computational model that uses X-ray images as a safer method to calculate patient lung volume. The first step consisted of obtaining mediastinal volumes from patient CT scans using the Pulmonary Toolkit in MATLAB. It was found that weight is the highest predictor of mediastinal volume in both male and female patients and that the mediastinal volume prediction is most accurate when both age and weight are taken into account. The second step involved the construction of a 3-dimensional ribcage model using MATLAB. The preliminary ribcage model was built using the Image Processing Toolbox, and X-ray image clustering was performed using the kmeans algorithm. There is a need for further testing to determine which reconstruction method, maximal intensity projection or volume rendering, is optimal for building the standardized ribcage model from CT scans. Further, it was determined that clustering is a promising technique to obtain X-ray coordinates for morphing the standardized ribcage model to individual patients, but there is a need for future investigators to optimize clustering. Future Capstone groups will be able to build upon this work in order to ultimately calculate lung volume by subtracting mediastinal constants from thoracic volumes found using the ribcage model and validate the accuracy of this framework.