Chapter 4 -- Chest Imaging Flashcards
What structures must ALWAYS be evaluated on a chest radiograph?
(1) Trachea and mediastinum; (2) heart and great vessels; (3) lungs and pulmonary arteries; (4) pleura and costophrenic angles; (5) diaphragm and abdomen; (6) bones and soft tissue.
What does a normal trachea look like?
Mid-line air-filled image; bifurcation is at the T4/T5 level. Deviation to the left is abnormal; the posterior soft tissue line should not be bowed or thick.
How is the mediastinum divided for examination?
Into three regions: anterior, middle, and posterior. The middle mediastinum contains the critical structures of the chest.
What are the lung markings made on a chest radiograph?
They are all pulmonary arteries or veins, not bronchi.
How many lobes are in each lung?
Three in the right lung, two in the left. Each lobe is divided into segments supplied by its own bronchus and blood vessels.
What are the two patterns of lung disease seen on a chest radiograph?
Acinar: diseases which affect the air spaces; and Interstitial: diseases which affect the interstitial tissue.
What are the two layers of the pleura?
Visceral (encases the lungs); and parietal.These are not normally visible, except on interlobar fissures. Thickening or distortion may occur with certain pathologies.
How does the diaphragm appear on chest radiograph?
As a smooth, dome-shaped structure on either side; surface irregularities are of little significance. The right-side is slightly higher than the left.
What soft tissue structures are typically visible on a chest radiograph?
Axillary fold produced by the pectoral muscles; supraclavicular and neck soft tissue; breast tissue; and sometimes nipple shadows.
What bony structures are typically visible on a chest radiograph?
Ribs; thoracic vertebrae; cervical vertebrae; clavicles; scapulae; and occasionally the heads of the humeri. The sternum is visible on the left lateral film. Cervical ribs may also be encountered.
What six pathologic patterns can alter the appearance of the lungs?
(1) Air-space disease (consolidation); (2) atelectasis (collapse); (3) pleural fluid accumulation (effusion); (4) masses (tumors); (5) emphysema (overinflation); (6) interstitial changes (fibrosis/edema).
What do fluid filled air spaces look like?
They lose their lucency and become opaque, fluffy, or cloud-like.
When will the border of and intrapulmonary abnormality NOT be seen on a chest radiograph?
When it is contiguous with the heart, aorta, or diaphragm.
What is the cervicothoracic sign?
A variant of the silhouette sign that is useful in determining if a mass that is seen above the level of the clavicle is intrapulmonary or mediastinal.
What does the cervicothoracic sign state?
If a mass is seen in its entirety, it lies posteriorly; if the border is obliterated, the mass must lie anteriorly.
