医学basicchestxraymodadam.ppt

Basic Chest X-Ray Interpretation,Adam Guttentag, M.D.,All photos retain the copyrights of their original authors, 2005 Adam Guttentag, MD,How do you look at a chest x-ray?,Avoid tunnel vision!,or,Have a system,The Lateral Chest Film,Find abnormalities hidden on the frontal film Confirm abnormalities suspected from frontal film Dont be afraid to look at it!,Our best friend!,Looking at the lateral CXR,Hilar structures on the lateral film,“Ring around the bronchus”,Technical Factors,Positioning straight vs oblique,(How well try to fool you),Effect of obliquity on heart size,Technical Factors,Positioning straight vs oblique PA vs AP,Technical Factors,Positioning straight vs oblique PA vs AP erect vs supine,erect,supine,Technical Factors,Positioning straight vs oblique PA vs AP erect vs supine lordotic vs kyphotic,lordotic,kyphotic,Technical Factors,Positioning straight vs oblique PA vs AP erect vs supine lordotic vs kyphotic,Effect on mediastinal contour,Technical Factors,Depth of inspiration Visualization of pathology depends on contrast provided by air in the lungs Count ribs!,10,8,Short of breath,One minute later,8,Technical Factors,Body habitus,Radiographic technique: Is it really different? Changing technique can make disease look better or worse.,Is the heart large? Is the mediastinum wide?,Same patient, 4 films within one month,Recognizing air space disease,Alveolar spaces filled withsomething. Radiologists report: “consolidation” “air space opacity” “fluffy density” “infiltrate” Nonspecific: Atelectasis, pneumonia, bleeding, edema, tumor,The Silhouette Sign,Indicates air space disease. Obscuration of a normally seen border, e.g. diaphragm or heart. Opacity with sharp edge along a fissure.,Localizing disease from the silhouette sign,Localizing disease from the silhouette sign,RUL,RML,UL,LL,RML or lingula,16 hours later,What happened here?,Lobar Atelectasis,Best sign shift of a fissure Rapid development and clearance Air bronchograms if non-obstructive Secondary signs: Mediastinal shift Elevated diaphragm Ribs closer together Vague increased density,LLL Atx,Next day,RUL Atx,RML Atx,LUL Atx,Pneumonia,Signs: Air bronchogram Silhouette - “positive” or “negative” Dense hilum “Spine” sign All are signs of any air space process Dx of pneumonia depends on appropriate clinical scenario.,Air bronchogram sign,Pseudomonas pneumonia,Lung cancer,Air bronchograms CT,Right middle lobe,Right upper lobe,Right lower lobe,Dense hilum, spine sign,Dense hilum, spine sign again,Four days later,Final Exam,21 y.o. with fever and cough,Hyperlucent hemithorax: why?,Did you notice the mass?,Lymphoma,Take home message #1,Its a chest x-ray, not a lung x-ray.,6 cm lung mass missed. How?,Take home message #2,Old films are your friend!,Elderly man with hypotension,Suddenly septic,Pneumatosis of small bowel,Take home message #3,The patient pays for the whole film!,Review Questions,All are kinds of air space disease except:,Hemorrhage Pneumonia Tumor Sarcoidosis Atelectasis,The most specific sign of atelectasis is:,Obscuration of a diaphragm Shift of a fissure Air bronchograms Density over the spine Mediastinal shift,This can make the heart look larger than it is:,Lordotic positioning AP positioning Expiratory film Supine positioning All of the above,Additional Reading,Chest Roentgenology Felson, B W.B. Saunders Co, Philadelphia 1973 Chapter 2: Localization of Intrathoracic Disease. pp 22-70. Pare JAP and Fraser RG Synopsis of Diseases of the Ch