Hiroshi Niimi

CT of chronic infiltrative lung disease: Prevalence of mediastinal lymphadenopathy

OBJECTIVE Our goal was to determine the prevalence of mediastinal lymph node enlargement at CT in patients with diffuse infiltrative lung disease. MATERIALS AND METHODS The study was retrospective and included 175 consecutive patients with diffuse infiltrative lung diseases. Diagnoses included idiopathic pulmonary fibrosis (IPF) (n = 61), usual interstitial pneumonia associated with collagen vascular disease (CVD) (n = 20), idiopathic bronchiolitis obliterans organizing pneumonia (BOOP) (n = 22), extrinsic allergic alveolitis (EAA) (n = 17), and sarcoidosis (n = 55). Fifty-eight age-matched patients with CT of the chest performed for unrelated conditions served as controls. The presence, number, and sites of enlarged nodes (short axis > or = 10 mm in diameter) were recorded. RESULTS Enlarged mediastinal nodes were present in 118 of 175 patients (67%) with infiltrative lung disease and 3 of 58 controls (5%) (p <0.001). The prevalence of enlarged nodes was 84% (46 of 55) in sarcoidosis, 67% (41 of 61) in IPF, 70% (14 of 20) in CVD, 53% (9 of 17) in EAA, and 36% (8 of 22) in BOOP. The mean number of enlarged nodes was higher in sarcoidosis (mean 3.2) than in the other infiltrative diseases (mean 1.2) (p <0.001). Enlarged nodes were most commonly present in station 10R, followed by 7, 4R, and 5. CONCLUSION Patients with infiltrative lung disease frequently have enlarged mediastinal lymph nodes. However, in diseases other than sarcoid, usually only one or two nodes are enlarged and their maximal short axis diameter is <15 mm.

Necrotizing sarcoid granulomatosis: computed tomography and pathologic findings.

Objective To describe the CT findings and corresponding pathological findings of necrotizing sarcoid granulomatosis (NSG). Materials and Methods We reviewed the high-resolution CT and macroscopic and histologie findings in three pathologically proven cases of NSG. Results The CT findings consisted of one case each with single nodule, multiple nodules, and parenchymal opacification. The abnormalities were peribronchovascular or subpleural in distribution. Historically, all patients had sarcoid-like granulomas with central necrosis and granulomatous vasculitis. The CT findings correlated closely with the gross pathologic findings. Conclusion We conclude that the CT manifestations of NSG reflect the variable macroscopic pathologic findings.

Quantification of Thin-Section CT Lung Attenuation in Acute Pulmonary Embolism: Correlations with Arterial Blood Gas Levels and CT Angiography

OBJECTIVE The purposes of this study were to investigate the frequency histogram of lung attenuation on CT angiography (CTA) in patients with and without acute pulmonary embolism (PE) and to evaluate the relation of the frequency histogram of lung attenuation and hypoxemia. MATERIALS AND METHODS Twenty-six patients with PE and 11 patients without PE who underwent CTA were evaluated with frequency histograms. We obtained quantitative parameters such as mean lung attenuation, median lung attenuation, SD, skewness, kurtosis, and the proportion of lung attenuation except for the median +/- 50 H (P +/- 50 H). Lung attenuation was also assessed visually and scored. The relationship between those histogram parameters, or visual score, and Pa(O2) was evaluated. CTA scores for evaluation of the degree of pulmonary artery obstruction were obtained, and the relation with Pa(O2) was assessed. RESULTS No significant differences were found in mean lung attenuation and median lung attenuation between patients with and without PE. Meanwhile, SD, skewness, kurtosis, and P +/- 50 H were significantly different between patients with and without PE (p = 0.0003, 0.0071, 0.0047, and 0.0028, respectively) and significantly correlated with Pa(O2) (r = -0.770, 0.797, 0.786, -0.871, respectively). Significant differences were found in visual scores between patients with and without PE (p < 0.0001). There were significant but relatively low correlations between CTA score and arterial blood gas levels (r = -0.442, p = 0.03). CONCLUSION In patients with acute PE, heterogeneity in lung attenuation is more prominent than in patients without PE.

Computed tomography measurements of overinflation in chronic obstructive pulmonary disease : Evaluation of various radiographic signs

Using computed tomography (CT), the authors determined significant signs of overinflation. Both the pulmonary function tests (PFT) and CT of 74 patients who underwent thoracic surgery for lung cancer (44 with normal lung function, 30 with chronic obstructive pulmonary disease) were reviewed. The following were correlated with forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC): tracheal index (transverse/anteroposterior diameter), sterno-aortic distance, thoracic cage ratios (anteroposterior/transverse diameters) at the tracheal carina (TC1) and 5 cm below (TC2); and depth of the azygoesophageal recess and the presence of intercostal lung bulging (ILB). Significant correlations were observed between FEV1/FVC and tracheal index (r = 0.578, p < 0.0001), TC1 (r = −0.523, p < 0.0001), TC2 (r = −0.533, p < 0.0001), and ILB (r = −0.462, p < 0.0001). Correlations were significant but weak between FEV1/FVC and sterno-aortic distance (r = −0.351, p = 0.0027) and depth of the azygoesophageal recess (r = −0.308, p = 0.0085). Reduced tracheal index and increased anteroposterior diameter of the thoracic cage correlated most significantly with a pulmonary function index of chronic airway obstruction.

High-Resolution CT Findings of Bronchiolitis Obliterans Organizing Pneumonia

Bronchiolitis obliterans with organizing pneumonia (BOOP) is histologically characterized by granulation tissue polyps in the lumina of alveolar ducts and bronchioles in association with a variable degree of interstitial and air-space infiltration by mononuclear cells and foamy macrophages. This art