Chest Xrays Flashcards
What is Density?
Often used interchangeably with opacity, density refers to an area on the X-ray that is brighter than expected. When X-rays are absorbed or blocked by something, such as the thick pus and mucous of a pneumonia, this shows up as a brighter spot on the lungs. Density or opacity are very nonspecific terms, and can represent a variety of lung pathologies.
Hyperechoic
What is Lucency?
Lucency is the exact opposite of density: more X-rays pass through less dense regions, such as air-filled lungs, resulting in darker areas on the image. On chest X-ray, lucency can be abnormal when there is too much of it (e.g. emphysema) or when present in an atypical location (e.g. pneumothorax).
Hypoechoic
What are Costophrenic Angles?
Where the diaphragm meets the ribs, blunting can be a sign of pleural effusion
Hemidiaphragm
Half the diaphragm is elevated: indicated abcess, hematoma, tumor, atelectasis, or rib fracture
Kerley Lines
Septal lines = fine thread-like lines produced by fluid or thickening of the septa between the lobules of the lung. Several different types of septal lines have been described1,2,4, but much the most common are those referred to as Kerley B lines.
Kerley B lines = fine horizontal lines approximately 1 cm long, situated perpendicular to the lateral pleural surface. They are most commonly seen just above the costophrenic angles on a frontal CXR
CXR orientations
Posterior anterior
Anterior Posterior
Posterior anterior
- Patient standing up
- beam passes through the patient from the back towards the front
- From Posterior to Anterior
The Image is viewed as if looking at the patent face-to-face
Considered the “standard”
Think the direction the xray travels through the patient
Anterior Posterior
- Patient unable to standing up (i.e. in bed)
- beam passes through the patient from the front towards the back
- From Anterior to Posterior
The Image is viwed as if looking at the patent face-to-face
Used when a PA CXR is not atainable
Think the direction the xray travels through the patient
PA -vs- AP
AP is lower quality and the heart is magnified (being an anterior structure)
So check the orientation before assuming the heart is enlarged!
CXR: taken on inspiraiton or expiration?
inspiration
Why is it better to have deeper inspirations on a CXR?
- shows more lung
- better image results
- less heart enlargement
What other qualities does a good CXR have?
centered image: shows the medial ends of the clavicle eqidistant from the midline
Pneumothorax: typical signs
Hyperinflated lung
deviated trachea
Pleural Effusion: typical signs
blunt costophrenic angles
What is a gastric bubble?
radiolucent rounded area under the left hemidiaphragm
represetns gas in the fundus of the stomach
