Squalene-Induced Lipoid Pneumonia in Rabbits: High-Resolution CT and Pathologic findings

PURPOSE: To describe the HRCT and pathologic findings of squalene-induced lipoid pneumonia in rabbits. MATERIALS AND METHODS: Three ml of squalene was instilled into the trachea between the second and the third tracheal ring in 16 rabbits. Serial HRCT scans were obtained on day 4 (n=8), at 1 week (n=7), 2 weeks (n=1), 4 weeks(n=1), 6 weeks (n=2) and 20 weeks (n=1) after squalene instillation. With sacrifice of the rabbits pathology was reviewed at 1 week (n=3), 4 weeks (n=3), and 6 weeks (n=4) after CT scans. RESULTS: Lipoid pneumonia was induced in 8 rabbits; lesions were distributed mainly in the dependent posterior lung. On serial HRCT scans, airspace consolidation, as seen on an air-bronchogrm, and nodular opacities were early findings; these gradually diminshed and with time were replaced by nodular & linear opacities. Histologically, pulmonary fibrosis appeared one week after squalene instillation and progressed over time. Alveolar septal thickening and cuboidal change of the alveolar lining epithelium were more prominent at week 6. CONCLUSION: The early change of squalene-induced lipoidpneumonia in rabbits is the proliferation of intraalveolar macrophage, which is responsible for air-space consolidation with air-bronchograms on HRCT. Nodular and linear opacities on HRCT are due to the appearance of pulmonary fibrosis one week after squalene instillation, and its subsequent progression.

Balloon Dilatation of Tuberculous Bronchial Stenosis :Immediate and Long Term Effect

PURPOSE: To evaluate the long-term immediate effects of balloon dilatation of the tuberculous bronchial stenosis. MATERIALS AND METHODS: Twenty-three women with tuberculous bronchial stenosis (19, left main bronchus ; 4, right main bronchus) underwent balloon dilatation (13 bronchoscopically guided ; 10 fluoroscopically guided). Immediate (n=23) and long-term follow-up (mean, 17.2 months; range, 1 month-6years 3 months; n=20) assessments focused on changes in the results of the pulmonary function test (PFT). An increase in FVC or FEVI of more than 10% after the procedure was considered effective. in all patients, any complications were evaluated. RESULTS: Balloon dilatation was effective at immediate follow-up in 69.5% of patients(16/23) and in 75.0%(15/20) atlong-term follow-up. Bronchoscopically and fluoroscopically-guided balloon dilatation proved effective in 61/5%(8/13) and 80.0% of patients (8/10) on immediate follow-up respectively, but in 90.0%(9/10) and 60/0%(6/10)on long term folow-up respectively. Balloon dilatation was effective in the active(n=10) and inactive(n=13) stage of tuberculous bronchitis in 80.0%(8/10) and 61.5% of cases(8/13) on immediate follow-up respectively, but in 66.6%(6/9) and 81.8%(9/11) on long term follow-up study, respectively. CONCLUSION: On immediate follow-up, balloon dilatation of tubular bronchial stenosis was more effective in the active than in the inactive stage, buton long-term foolow-up was less effective; long-term improvement in the inactive stage was, however, well-maintained.

Differentiation of Exudative and Transudative Pleural Effusion: MR Appearances

PURPOSE: The purpose of this study is to determine whether MR images after intravenous administration of Gd-DTPA can differentiate exudative and transudative pleural effusion. MATERIALS AND METHODS: We studied 18 patients with ten exudative and eignt transudative pleural effusions diagnosed clinically and by thoracentesis. We analysed the relationship between T1 value(normalized to fat) and the ratio of effusion/serum protein of pleuraleffusion. We also assessed the contrast enhancement of exudative and transudative pleural effusion on T1 weighted SE images taken at 15 and 30 minutes after administration of Gd-DTPA. RESULTS: The relationship between the effusion/serum protein ratio and T1 value(normalized to fat) was statistically not significant(r=0.27, P=0.381).On precontrast spin-echo T1W1, mean signal intensity of the transudate was 0.18 (+/-0.04) and that of the exudatewas 0.24(+/-0.07), values which were not significant differences(P>0.05). Postcontrast mean signal intensities of transudates at 15 and 30 were 0.20+/- 0.06 and 0.26+/-0.08, respectively, values which were not significantly higherthan that of precontrast mean signal intensity(P<0.05). Postcontrast mean signal intensity values of exudative pleural effusions at 15 and 30 mimutes(0.32+/-0.06 and 0.39+/-0.06, respectively) were, on the other hand, significantly higher than that of precontrast mean signal intensity(P<0.05). CONCLUSION: Postcontrast T1-weighted SE images at 15 and 30 minutes can be helpful in the differentiation of transudative and exudative pleural effusion.