B i.e. Asbestosis - Asbestos related lung disease presents with pleural effusion (small, blood stained, persistent, recurrent, bilateral), pleural plaques (bilateral, multifocal, exclusively involving parietal pleura along posterolateral & lateral chest wall b/w 6-10th ribs and sparing visceral pleura, apices & costophrenic angles), pleural calcification (bilateral diaphragmatic calcification with clear CP angles is pathognomic), diffuse pleural thickening (involves visceral pleura & 1/t impaired lung function), asbestosis, pseudotumor (round atlectasis) & malignancy. - Asbetosis may present with fine to coarse reticulonodular pattern causing loss of clarity of diaphragm & cardiac shadow (Shaggy hea) on x ray. HRCT (investigation of choice) shows subpleural pulmonary arcade, pleural based nodular irragularities, parenchymal bands & septal lines Round atelectasis occurs mostly in peripheral, lower, dorsal (posterior) lobes adjacent to visceral pleuraQ and presents with Comet taiVVaccum cleaner/ Crow's feet sign and Swiss cheese air bronchogramQ Predilection for Lower ZoneQ (Whole lung may be involved with predominant lower zone involvement) Asbestosis Related Lung Disease: Asbestos is the generic term used for heat resistant fibrous silicates. They are classified into 2 groups. 1) Straight, rigid, needle like Amphiboles (eg commercial crocidolite = blue/black asbestos & amosite = brown asbestos; and non- commercial contaminating amphiboles such as actinolite, tremolite & anthophyllite); 2) Serpentines (nonamphiboles) such as commercial chrysolite = white asbestos. - Aspect (length-to-diameter) ratio decides carcinogenicity. Amosite & crocidolite are relatively malignant, whereas anthophyllite, chrysotile and tremolite are benign. - Apa from pleural effusion, which may be present as early as 5 years post exposure, the typical abnormalities do not appear until 20 years or more after initial exposure. - D/t asbestos, exposure may occur in asbestos industry, ship building & textile