Intro to the chest radiograph Matthew Bentz, MD OHSU Diagnostic Radiology Assistant Professor 2015 Goals for today Start with normal vs abnormal Try to develop a mental picture of normal See some commonly encountered and important chest radiograph findings Teaching points 1)Name the 5 densities that are seen on standard radiographs 2)Choose and utilize a standardized way to view each radiograph 3)Locate the following anatomic structures: Trachea, carina, subclavian artery and vein, SVC, cavoatrial junction 4)Name the 6 patterns seen on chest imaging Blank x ray film Under exposure & over exposure Density the key to x ray films Tissue depth and density matter Depth and density matter Physics too physical density and density to x rays both matter Density Concept Organ boundaries are seen only when the densities are different between the tissues Examples: Pulmonary vessels are sharply seen in normal lungs (Soft tissue air interface) Airways are not seen in normal lung (Air Air interface) Airways not visible in normal lungAirways visible in abnormal lung Density is key! Converse is true also - If objects have, or develop, the same density, they will be inseparable on CXR Density is key! Converse is true also - If objects have, or develop, the same density, they will be inseparable on CXR ? Air Fat Densities Water/tissue Bone Metal Tissue appearance on x-rays Teaching point #1 Name the 5 densities that are seen on standard radiographs Air Fat Densities Water/tissue Bone Metal Conceptualize If you know what a cow looks like And you know the color purple You can recognize a purple cow, even if youve never see one Quiz Air Fat Densities Water/tissue Bone Metal Quiz Cartilage is water/soft tissue density Since it is the same density as the adjacent tissue, there is no visible boundary i.e. cartilage is invisible on radiographs Quiz #2 Quiz picture #3 1 views is no views Titanic Normal chest X ray Pretty easy to spot Really hard to spot Are all the lines and tubes ok? A brief digression into technique related issues PA versus AP Examination Scapula Position Can Help AP View: 10% magnification Patient body habitus Rotation Rotation: Medial Clavicles With Reference To The Spinous Process (Arrows) Rotated to RPO/LAO Rotated to LPO/RAO Approaches to a CXR Alphabet method Between, inside, outside the lungs Top down Other My approach: Abnormalities, right lung, left lung, compare the two lungs, trachea, mediastinum, heart, outside the lungs (including abdomen) and bones Alphabet Air Alphabet Air Bone Alphabet Air Bone Cardiac Alphabet Air Bone Cardiac Diaphragm Alphabet Air Bone Cardiac Diaphragm Everything else BIO Between Inside Outside BIO Between Inside Outside BIO Between Inside Outside Top Down My Method