Usual interstitial pneumonia and nonspecific interstitial pneumonia with and without concurrent emphysema: thin-section CT findings.

PURPOSE: To determine whether concurrent emphysema influences the distinction between usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP) at thin-section computed tomography (CT). MATERIALS AND METHODS: Institutional review board approval was obtained for this retrospective study; informed consent was not required. The study included 54 patients with NSIP and 42 patients with UIP (55 men, 41 women; mean age, 60.2 years +/- 9.2 [standard deviation]; age range, 33-77 years). Two independent readers assessed the CT images and made a first-choice diagnosis. The appearances of UIP and NSIP at CT were compared with univariate and multivariate analyses. Receiver operating characteristic curves were used to determine how concurrent emphysema influences the distinction of UIP from NSIP at thin-section CT. RESULTS: The diagnosis was correct in 136 (71%) of 192 readings. In patients with concurrent emphysema, the diagnosis was correct in 30 (44%) of 68 readings. Sensitivity, specificity, and accuracy for diagnosis were lower in patients with concurrent emphysema than in patients without concurrent emphysema. In patients with concurrent emphysema, there were no significant differences in extent of fibrosis, extent of honeycombing, extent of consolidation, coarseness of fibrosis score, extent of traction bronchiectasis, upper lung irregular lines, peribronchovascular distribution, and nodules between UIP and NSIP. According to multivariate analysis, the CT feature that helped best differentiate UIP from NSIP in patients with emphysema was traction bronchiolectasis. CONCLUSION: Concurrent emphysema influenced the distinction between UIP and NSIP.

Quantitative CT in chronic obstructive pulmonary disease: inspiratory and expiratory assessment.

OBJECTIVE: The purpose of this study was to determine whether measurements of lung attenuation at inspiration and expiration obtained from 3D lung reconstructions reflect the severity of chronic obstructive pulmonary disease. SUBJECTS AND METHODS: Seventy-six patients with chronic obstructive pulmonary disease underwent MDCT with 3D postprocessing at full inspiration and full expiration. Inspiratory and expiratory mean lung density, percentage of lung volume with attenuation values less than -910 HU and -950 HU at inspiration and expiration, expiratory to inspiratory mean lung density ratio, and fifth and 15th percentiles of the lung attenuation distribution curve at inspiration and expiration were measured. RESULTS: When forced expiratory volume in the first second of expiration (FEV(1)) was 50% or greater than predicted value, mean lung density and lower attenuation volume measured from inspiratory MDCT scans correlated better with FEV(1) and ratio of FEV(1) to forced vital capacity (FVC) than did those from expiratory scans. When FEV(1) was less than 50% of predicted value, mean lung density and lower attenuation volume measured from expiratory MDCT scans correlated better with FEV(1) and ratio of residual volume to total lung capacity than did those values from inspiratory scans. Fifth percentile and 15th percentile of the lung attenuation distribution curve at both full inspiration and full expiration correlated well with FEV(1)/FVC and diffusing capacity of the lung for carbon monoxide as a percentage of predicted value but not well with FEV(1) as a percentage of predicted value regardless of FEV(1). CONCLUSION: Measurements of lung attenuation obtained at inspiration and visual score better reflect abnormal results of pulmonary function tests in patients with less severe chronic obstructive pulmonary disease than do measurements obtained at expiration. Measurements of lung attenuation obtained at expiration better reflect pulmonary function abnormalities in patients with severe chronic obstructive pulmonary disease.

Influence of in vitro radiation on changes in nitric oxide in rat macrophages and smooth muscle cells.

We examined changes in nitric oxide (NO) levels resulting from irradiation of rat macrophage (RAM) and smooth muscle cells (SMC) in medium. Irradiation did not alter the NO concentration in the medium of either cell line. However, irradiation of 5 and 20 Gy enhanced the concentration of NO induced by lipopolysaccharide (LPS) in the medium containing RAM. Furthermore, 20 Gy of irradiation suppressed NO production induced by interferon-gamma in the RAM medium. Radiation seemed to enhance NO production more than that caused by Interleukin 1-beta only in the medium containing SMC. Next, mRNA levels of inducible NO synthase (NOS) were examined in RAM by Northern blotting following irradiation. Five Gy of irradiation did not generate iNOS mRNA expression, but did enhance iNOS piRNA expression induced by LPS, while 20 Gy suppressed the expression level of iNOS mRNA more than 5 Gy. This leads to the conclusion that radiation stimulation induced NO production through indirect action on the macrophage.