[Utilization of NIH image for quantification of emphysema by computed tomography].
The percentage of the low attenuation area (LAA%) is understood to be the most accurate index in quantifying emphysema by computed tomography (CT). To date, CT scanners with enhanced post-processing programs have been used for measurements of LAA%. In this study, we sought develop a method of LAA% determination using a conventional density mapping program for CTs and NIH Image, an image-analysis software package for personal computers. Our results for overall LAA%, together with the correlations between overall LAA% and pulmonary function tests, agreed well with the findings of earlier reports. In reproducibility trials utilizing our method interoperator error for LAA% was within +/- 2%. A phantom experiment indicated that there was little difference between LAA% values obtained by this method and the values obtained by direct CT measurements. Therefore, we concluded that this method is sufficiently reliable for clinical use and capable of facilitating LAA% measurements with CT scanners that are not equipped with enhanced post-processing software.
Third Department of Internal Medicine, Faculty of Medicine, Tottori University, Japan.
Y
Y
Hitsuda
Y
Y
Kawasaki
T
T
Igishi
K
K
Yasuda
M
M
Mikami
K
K
Kato
S
S
Matsumoto
T
T
Sasaki
D000368:Aged; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015203:Reproducibility of Results; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*