The most interesting findings of CT chest in the current study are air trapping, bronchiectasis, and ground-glass opacity.
In the current study, more than half of the cases showed air trapping; we excluded lung regions of air trapping limited to a single secondary pulmonary lobule during analysis.
In order to detect the presence of air trapping in the lungs, lung volumes should be measured to determine the total lung capacity and the residual volume.
Secondly, in order to assess whether [FEV.sub.3]/FVC (accordingly, 1-[FEV.sub.3]/FVC) provides additional information on air trapping and hyperinflation to that of [FEV.sub.1]/FVC, we analysed correlations of [FEV.sub.3]/FVC abnormality.
Other CT findings were as follows:
Air trapping in 9/24 (37.5%) [Figure 2], reticulation in 8/24 (33.3%), and traction bronchiectasis in 2/24 (8.3%).
The incidence of
air trapping increased with age and
air trapping was not detected before 30 years of age (Table 6).
Air trapping was not seen in 6 patients, whereas 10 (35.7%) patients had mild, 9 (32.1%) had moderate and 3 (10.7%) had severe
air trapping.
* CT shows
air trapping, more evident during expiration.
Median and 10th percentile lung attenuation curves, however, remained significantly left-shifted at 22 hours, which indicates increased
air trapping (mean change-15.88 Hu and-10.42 Hu, respectively).
Asthma is described as an "
air trapping" disease where air enters the lungs normally, but has difficulty leaving.
Other CT findings in HP include areas of decreased attenuation,
air trapping, poorly defined nodules, and honeycomb lung (23,24).
In congenital cystic adenomatoid malformation, an absence of bronchial cartilage leads to
air trapping. This may lead to airway collapse.
However, there was a significant reduction in
air trapping by residual volume/ total lung capacity ratio following triangular waveform HFCWO (p = 0.01).
Mild
air trapping, which is generally seen in smokers and the elderly, was more pronounced in the study patients, whose average age was 48.5 years.
The effective tracheal diameter that causes
air trapping during jet ventilation.