Lecture 2- CXR Basics Flashcards
Viewing CXR
steps for viewing
- position radiograph correctly
- view as a whole for obvious abnormality
- view systematically
within the body… radidation is
3
- completely absorbed
- transmitted unchanged through the pt
- scattered within the body
Views
4 typical views
- posterior anterior (PA)
- lateral
- anterior posterior (AP)
- lateral decubitus
Views
describe CXR PA view
4 components
- gold standard for front view of lungs
- pt stands upright with the anterior of chest placed against the front of the film (radiation goes through the back to the front)
- shoulders are rotated forward to touch the film to ensure the scapula are out of the way
- take image with full inspiration
Views
describe CXR AP view
4 components
- used when the pt is immobilized or unable to do PA procedure
- patient is supine with patient’s back against the film
- heart is at a greater distance from the film so it will be enlarged
- scapula are visible
Views
describe CXR lateral view
3 components
- pt standard upright with one side of the chest against the film
- allows the viewer to see behind the heart and diaphgragmatic dome
- done in conjunction with PA view to help determine 3D location of anormalities
Views
describe CXR lateral decubitus view
- pt lies on the L or R side (ensure it’s labelled properly)
- often used to reveal pleural effusion that can’t be observed in upright view
what constitutes the hilum
- pulmonary arteries & branches
- pulomnary veins
- adjacent airways
Views
which CXR view shows the truest size of the heart?
- PA view
- AP view magnifies the heart
Views
t/f the heart may also seem enlarged if the pt doesn’t take a full breath
TRUE- must take full breath in to truly gauge heart size
Chest Anatomy
go to ppt and label the components of the mediastinum.
ok
define
- radiolucent
- radio-opaque
- radiolucent: allows xray to go through (black/air)
- radio-opaque: blocks xray from going through (white/bone)
CXR Interpretation
ABCs of CXR Interpretation
- Assess the quality of the CXR
- Airway
- Bones/Borders
- Cardiac Assessment
- Diaphragms
- Effusions
- Fields
CXR Interpretation
Describe components of assessing the quality of an image
PIER
* Positioning (PA, Lat, AP, decubitus)
* Inspiratory Effort (8-10 countable ribs)
* Exposure/penetration (vertebrae are just visible behind the heart)
* Rotation (clavicular heads equi-distant from spinous process; clavicular head attached at T4)
CXR Interpretation
A-Airway: what are you assessing?
- trachea - look for midline/shifting/narrowing
- maybe can see where trachea splits at the carina?
- want to see through to the aortic arch
CXR Interpretation
B- Bones, Borders, Soft Tissues
what do we evaluate here?
Bones:
* look at each rib
* clavicles
* lower cervical and thoracic spine
* scapulae/humeri if visible
* are there bone lesions? spinous processes lined up?
Soft Tissues
* abnormalities of the skin/breast/body parts?
Borders
* supraclavucular fossae (nodes)
* Lateral chest wall
* Under diaphragm
CXR Interpretation
what can breast tissue obscure?
costophrenic angles
CXR Interpretation
what may lucencies within soft tissue represent?
gas
CXR Interpretation
C- Cardiac
what do we evaluate here?
- 2/3 of heart should lie on L side of chest w/ 1/3 on the R side
- heart should take up less than 1/2 of the thoracic cavity (measured horizontally)
- LA and LV create L heart border
- RA creates R heart border
CXR Interpretation
D- diaphragm
what do we evaluate here?
- both diaphragms should form a sharp margin w/ the lateral chest wall
- both diaphragm contours should be clearly visible medially to the spine
CXR Interpretation
E- effusions
what do we evaluate here?
- effusion: fluid where fluid shouldn’t be (outside border of lung)
- the pleura and pleural spaces will only be visible when there is an abnormalities present
CXR Interpretation
F- fields
what do we evaluate here?
- normally, there are visible markings throughout the lungs due to the pulm arteries/veins which continue to the chest wall
- both lungs should be scanned starting at the apex and working downward
CXR Interpretation
describe lung fissures on CXR
- likely not visible but can be seen
- horizontal & transverse on R lung/transverse on L lung
- the major fissures are not usually seen on a PA view because they are viewed obliquely
CXR Interpretation
go to ppt and label the lobar anatomy.
ok
Lung Disease
6 basic patterns of lung disease
- air space opacities
- interstitial opacities
- nodules/masses
- lymphadenopathy
- cysts/cavities
- pleural abnormalities
Lung Disease
what might cause air space opacities
- replacement of air in the alveolar space by inflammatory cells, pus, blood, water, tumor cells
Lung Disease
what is an air bronchogram?
- characteristic manifestation of air-space opacity which refers to the phenomenon of air-filled bronchi (dark) being made visible by the opacification of surrfounding alevoli
- looks like a dark spot (literally just an air space)
Lung Disease
what are interstitial opacities?
- involvement of the supporting tissue of the lung parenchyma
- generalized miliary patterns, Kerley B lines, reticular/septal lines, peribronchovascular thickening, nodules
Lung Disease
what does generalized miliary pattern mean?
innumerable amount of small opacities in the interstitial space
Lung Disease
differentiate Kerley A and B lines
- A: around hilum
- B: around bases/lateral sides
Lung Disease
what are reticular formations typically seen with?
pulmonary fibrosis
Lung Disease
differentiate nodules and masses
- nodules: < 3 cm
- masses: > 3 cm
- both: clearly defined opacities
Lung Disease
describe solitary pulmonary nodules
- common clinical probelm (>50% of smokers aged 50+)
- single, small (< 3cm), well-circumscribed, radiographic round opacity on chest imaging surrounded by normal lung
- not associated with infiltrate, atelectasis, or adenopathy
Lung Disease
describe multiple pulmonary nodules
- more worrisome for malignancy than SPNs
- same risk factors for malignancy, but more likely to be metastatic than a SPN
Lung Disease
which cancers are most likely to metastasize
5
- colorectal
- breast
- renal cell
- uterine leiomyosarcoma
- head/neck squamous cell carcinoma
Lung Disease
describe lymphadenopathy
- abnormal contouring of mediastinal shadows (LOOK AT THE HILUM!)
- characteristic locations: R paratracheal area, hilar regions, aortopulomary window, subcarinal region, superior mediastinum
Lung Disease
describe cysts/cavities
- occur in the pulmonary parenchymal space and when abnormal they contain air/fluid/both (normal = lung tissue)
- cysts: thin walled filled with cellular elements
- Cavities: created by tissue necrosis within a lung nodule/mass (become air-filled when the internal necrotis elements are expelled into the tracheobronchial tree)
Lung Disease
what pleural abnormalities can be seen?
3
- pleural effusion
- pleural thickening
- pleural calcifications
Lung Disease
describe pleural effusion findings on CXR
blunting of the costophrenic angle to form a crescent shaped opacity
Lung Disease
describe pleural thickening CXR findings
nondependent and non free flowing
Lung Disease
describe when pleural clacifications are seen?
- asbestos-related pleural disease
- sequelae of prior hemothorax or tuberculosis
infiltrates vs consolidation
- infiltrate: fluid in the lung
- consolidation: hardening or thickening of the infiltration
Lung Disease
pneumothorax
- no lung markings in pleural space
- mediastinum shifts to the CONTRALATERAL side
- deep sulcus sign: the costophrenic sulcus is significantly lower than on the ipsilateral side
- prominent vascular markings in the opposite lung (because it is receiving entire cardiac output)
