Small pneumothorax can be best demonstrated by?

Ans. b (Chest X-ray in inspiration and expiration) (Ref. Grainger & Allison's Diagnostic Radiology, 5th ed.)Special chest radiographic viewsUse1Lordotic view# To detect lesions of middle lobe (like collapse) and collection in fissure and subtle infiltrates in UZS.2Oblique views# To demonstrate the retrocardiac space, the posterior CP angles and the chest wall, with pleural plaques being clearly demonstrated.3Decubitus view# To demonstrate small amount of pleural fluid, that is not seen on PA view.4Paired inspiratory and expiratory views# To demonstrate air trapping, small pneumothorax, interstitial shadowing, diaphragm movements, and inhaled foreign body in children.5Lateral view# Retrosternal space is best seen in lateral view.6Oblique view# The retrocardiac space is seen well on oblique view.7Films exposed in expiration# To demonstrate air trapping, particularly in pediatric practice for any patient suspected of having inhaled a foreign body.# To demonstrate a small pneumothorax and interstitial shadowing.Acquiring a CXR# Usually a CXR is taken by using kV between 80-120 with a FFD of 6 feet (1.85 m) reduces magnification and produces sharper image.# Using a low kVp (60-80 kV) produces a high-contrast film with miliary shadowing and calcification being seen more clearly.# With high voltages (120-170) the films are of lower contrast with | visualization of hidden areas of lung, better penetration of mediastinum and better demonstration of normal, vessel markings and abnormal opacities.# 1 rad = 1 rem = 0.01 mSv# The effective dose equivalent from resulting from chest radiographic examination is 0.6 mSv (6 mretn or mrad)# One CT thorax (8 mSv) is equivalent to 400 CXR