Pulmonary ground-glass nodules: increase in mass as an early indicator of growth.

Purpose: To compare manual measurements of diameter, volume, and mass of pulmonary ground-glass nodules (GGNs) to establish which method is best for identifying malignant GGNs by determining change across time.

Materials And Methods: In this ethics committee-approved retrospective study, baseline and follow-up CT examinations of 52 GGNs detected in a lung cancer screening trial were included, resulting in 127 GGN data sets for evaluation. Two observers measured GGN diameter with electronic calipers, manually outlined GGNs to obtain volume and mass, and scored whether a solid component was present.

Automatic segmentation of pulmonary segments from volumetric chest CT scans.

Automated extraction of pulmonary anatomy provides a foundation for computerized analysis of computed tomography (CT) scans of the chest. A completely automatic method is presented to segment the lungs, lobes and pulmonary segments from volumetric CT chest scans. The method starts with lung segmentation based on region growing and standard image processing techniques.

Image subtraction facilitates assessment of volume and density change in ground-glass opacities in chest CT.

Objectives: To study the impact of image subtraction of registered images on the detection of change in pulmonary ground-glass nodules identified on chest CT.

Materials And Methods: A cohort of 33 individuals (25 men, 8 women; age range 51-75 years) with 37 focal ground-glass opacities (GGO) were recruited from a lung cancer screening trial. For every participant, 1 to 3 follow-up scans were available (total number of pairs, 84).