Chest
Quantitation of Emphysema by Computed Tomography Using a “Density Mask” Program and Correlation with Pulmonary Function Tests
Section snippets
METHODS
We studied 85 patients, 52 males and 33 females, ranging in age from 40 to 78 years (mean age ± SD = 64 ± 8 yr). They were selected from patients tested in the Vancouver General Hospital Pulmonary Function Laboratory during investigation for suspected malignancy. Patients with tumors were included if the tumor was peripheral and less than 7 cm in diameter or central but obstructing one segment or less. The limit for a peripheral lesion of 7 cm in diameter was chosen since the volume of a
RESULTS
The CT “density mask” results for both lungs are summarized in Table 1, which shows mean lung density, total CT lung volume, total volume of emphysema, and percentage of lung with emphysema. There was good correlation between the mean lung density and each of the following: total CT lung volume, total CT volume of emphysema and percentage of lung with emphysema (all absolute r values = 0.66 to 0.67, p<0.001). The correlation between mean lung density and percentage lung involvement with
DISCUSSION
In this study we used the CT “density mask” program to quantitate areas with attenuation values less than —910 HU which were taken to represent areas of emphysema,10 and to provide an overall percentage of lung involvement by emphysema. The CT quantitation of emphysema was correlated with mean lung density, overall lung volume and with commonly performed pulmonary function tests that are affected in emphysema.
The mean lung density was found to correlate well both with the total CT lung volume
REFERENCES (25)
- et al.
Computed tomography in pulmonary emphysema
Clin Radiol
(1982) - et al.
Diagnosis of pulmonary emphysema by computed tomography
Lancet
(1984) - et al.
“Density mask”: an objective method to quantitate emphysema using computed tomography
Chest
(1988) The radiology of emphysema
Clin Chest Med
(1983)- et al.
The definition of emphysema: report of a National Heart, Lung and Blood Institute, Division of Lung Diseases Workshop
Am Rev Respir Dis
(1985) - et al.
CT in the qualitative assessment of emphysema
J Thorac Imag
(1986) Computed tomography of the thorax
Radiol Clin North Am
(1978)- et al.
Computed tomography of the lung
Radiology
(1978) - et al.
Pathological evaluation of computed tomography images of the lungs
J Clin Pathol
(1982) - et al.
The diagnosis of emphysema: a computed tomographic-pathologic correlation
Am Rev Respir Dis
(1986)
Centrilobular emphysema: CT-pathologic correlation
Radiology
A theoretical and experimental analysis of anomalies in the estimation of pulmonary diffusing capacity by the single breath method
Q J Exp Physiol
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Supported in part by grants from the Medical Research Council of Canada (MA-10042) and the B.C. Lung Association.
Manuscript received April 24; revision accepted July 10.