Related Experiment Video
Updated: Jun 6, 2026

Automated Measurement of Pulmonary Emphysema and Small Airway Remodeling in Cigarette Smoke-exposed Mice
Published on: January 16, 2015
Repeated low-dose computed tomography in current and former smokers for quantification of emphysema
Alexander McGregor1, Heidi C Roberts, Zhi Dong
1Department of Medical Imaging, University Health Network, Toronto, Ontario, Canada.
Objective:
To quantify different emphysema evolution in current and former smokers.
Methods:
We retrospectively analyzed low-dose computed tomography scans from a lung cancer screening study of 59 current and 75 former smokers. The quantitative emphysema analysis was performed using a home-built software (YACTA version 0.9), yielding the parameters lung volume, emphysema volume (EV), emphysema index (EI), mean lung density, and 15th percentile.
Results:
The baseline EV and EI were significantly different (median EVformer =422 mL vs EVcurrent =249 mL, P = 0.0003; and median EIformer =7.6 % vs EIcurrent =4.1 %, P = 0.0001, respectively). On the annual repeat scan, the median EI and EV for former smokers had decreased significantly (ΔEIformer = -0.257%, P = 0.004; and ΔEVcurrent = -0.203 mL, P = 0.020), whereas there was no emphysema change in current smokers.
Conclusions:
We were able to demonstrate different emphysema evolution in current versus former smokers; emphysema parameters decreased in the former smokers and remained stable in current smokers.
Related Concept Videos
Chronic Obstructive Pulmonary Disease II: Emphysema
Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies
Medical History
Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
Pulmonary Embolism II: Diagnostic Studies and Interprofessional Care

