Automated approach to measure pulmonary nodule volume based on radius and CT number

Determining the change in the pulmonary nodule size is a critical measurement for cancer diagnosis and therapy evaluation. In this study, an image-processing method that quantifies the nodule volume change based on computed tomography (CT) images is proposed. The proposed method consists of the following four steps: CT image interpolation, pulmonary region segmentation, nodule extraction, and nodule volume measurement. Nodule extraction is performed based on the radius and CT number. The proposed method was applied to a public database (Volcano ‘09). We confirmed that the nodule volume measurements performed using our proposed method were successful, according to a subjective evaluation.