Dependent Lung Opacity at Thin-Section CT: Evaluation by Spirometrically-Gated CT of the Influence of Lung Volume
Korean Journal of Radiology
;
: 24-29, 2002.
Article
in English
| WPRIM
| ID: wpr-121152
ABSTRACT
OBJECTIVE:
To evaluate the influence of lung volume on dependent lung opacity seen at thin-section CT. MATERIALS ANDMETHODS:
In thirteen healthy volunteers, thin-section CT scans were performed at three levels (upper, mid, and lower portion of the lung) and at different lung volumes (10, 30, 50, and 100% vital capacity), using spirometric gated CT. Using a three-point scale, two radiologists determined whether dependent opacity was present, and estimated its degree. Regional lung attenuation at a level 2 cm above the diaphragm was determined using semiautomatic segmentation, and the diameter of a branch of the right lower posterior basal segmental artery was measured at each different vital capacity.RESULTS:
At all three anatomic levels, dependent opacity occurred significantly more often at lower vital capacities (10, 30%) than at 100% vital capacity (p = 0.001). Visually estimated dependent opacity was significantly related to regional lung attenuation (p < 0.0001), which in dependent areas progressively increased as vital capacity decreased (p < 0.0001). The presence of dependent opacity and regional lung attenuation of a dependent area correlated significantly with increased diameter of a segmental arterial branch (r = 0.493 and p = 0.0002; r = 0.486 and p = 0.0003, respectively).CONCLUSION:
Visual estimation and CT measurements of dependent opacity obtained by semiautomatic segmentation are significantly influenced by lung volume and are related to vascular diameter.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Spirometry
/
Tomography, X-Ray Computed
/
Vital Capacity
/
Lung
/
Lung Volume Measurements
Limits:
Adult
/
Female
/
Humans
/
Male
Language:
English
Journal:
Korean Journal of Radiology
Year:
2002
Type:
Article
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