J Comput Assist Tomogr , Volume 33, Number 5, September/October 2009
Hiromitsu Sumikawa, MD, PhD, Takeshi Johkoh, MD, PhD, Shuji Yamamoto, PhD, Masahiro Yanagawa, MD,Atsuo Inoue, MD, PhD, Osamu Honda, MD, PhD, Shigeyuki Yoshida, MD, Noriyuki Tomiyama, MD, PhD, and Hironobu Nakamura, MD, PhD
Objective: The aim of this study was to determine the computed tomography (CT) values of various pulmonary abnormalities in cubic region of interest (ROI) and square ROI and evaluate the CT findings by histogram analysis in the ROI.
Methods: The study included 89 patients with the following 8 pulmonary CT patterns: normal lung, ground-glass attenuation, fine reticular opacity, coarse reticular opacity, honeycombing, airspace consolidation, nodular opacity, and emphysema, Cubic and square ROIs were selected in each CT pattern, and 5 values (contrast, variance, entropy, skewness, and kurtosis) were calculated.
Results: In the histogramof ground-glass attenuation, fine reticular opacity, and coarse reticular opacity, peaks had moved to the right compared with the normal lung. Only emphysema had higher contrast and lower entropy than the normal lung (P < 0.001). The other abnormalities had lower contrast and higher entropy than the normal lung. Conclusions: In conclusion, the shapes of histograms were characteristic of various abnormalities of the lung, and the values reflected the histogram quantitatively.