J Korean Radiol Soc.
1995 Oct;33(4):551-558.
Respiratory Dynamic CT of the Lung: Initial Clinical Experience
Abstract
- PURPOSE
We applied spiral CT to evaluate the dynamic changes of regional ventilation of the lung in normal
subjects and abnormal patients.
MATERIALS AND METHODS
This study includes normal subjects (n:5) and patients with chronic obstructive
pulmonary disease (n=4), small air-way disease (n=3), diffuse panbronchiolitis (n=4), and tracheobronchial
tuberculosis (n=2). Time-continuous scan data at a fixed level during forced vital capacity maneuver (10--12
seconds) were obtained and images were reconstructed retrospectively by using 0.67 second scan data per
image. The reconstructed images were displayed in a cine mode. Time-density curves were plotted and were
correlated with clinical diagnosis.
RESULTS
In normal subjects, mean attenuation difference between full inspiration and full expiration was 145.
8HU and mean time interval between 20% expiration and 80% expiration was 2.04 seconds. In chronic obstructive
lung disease, mean attenuation difference between full inspiration and full expiration was 21.2HU and
mean time interval between 20% expiration and 80% expiration was 3.63 seconds. In small air-way disease,
mosaic-pattern hyperlucency and normal portion of lung showed mean attenuation differences between 20%
expiration and 80% expiration to be 49.8HU and 167.0HU, respectively. In diffuse panbronchiolitis, centrilobular
region and normal portion of lung showed mean attenuation differences between 20% expiration and 80%
expiration to be 35.4HU and 79.3HU, respectively.
CONCLUSION
Respiratory dynamic CT is an updated technique which enable imaging of the functional status
of the lung parenchyma. It may be useful in differentiation and quantitation of variable obstructive lung
diseases.