CXR interpretations Flashcards
what type of tissue does not allow as much radiation to pass through resulting a lighter reflected image and vise versa
deep tissue
This also results in absorption of the radiation by the anatomical structure
structures the x-ray beam hits first will look like how ?
magnified in relation to those which are closer tot he detector
indications for CXR
- Persistent cough
- SOB
- Wheezing
- Chest pain/injury
- Fever (unexplained)
- Monitoring of disease resolution or progression
- Lymphadenopathy (unexplained)
what must be asked/done for female pts before obtaining a CXR
LMP/pregnancy test
CXR views
- Posterior-Anterior (PA)
- Lateral
- Lateral Decubitus
- Expiratory
5.Lordotic - Anterior-Posterior (AP)
what CXR views are standard since they provide the most accurate reproduction of the anatomical structures
PA and lateral
this CXR view is performed with the chest against the detector
PA
this CXR view is performed with the left side of the body against the detector
lateral
what is this CXR view
PA
what is this CXR view
lateral
indications to order lateral decubitus CXR
- pleural effusions vs consolidation
- loculated effusions vs free pleural fluid
- evaluate for small pneumothorax
how do you position a pt for CXR with pleural effusions
the side of interest should be down
how do you position a pt for CXR with pneumothorax
the side of interest should be up
what is the expiratory view CXR for?
FB with air trapping
affected side will appear larger
Small pneumothoraces may be more pronounced
what is the Lordotic CXR view for?
evaluation of the lung apices that appear obscured on the PA/AP
what is the AP CXR for?
performed supine or sitting
reserved for patients who cannot stand erect
differences you’ll see between PA vs AP CXRs
- PA
- clavicle in lung field
- ribs slanted
- scapula outward of lung
- heart shadow is smaller - AP
- clavicle at top of lung
- ribs horizontal
- scapula in lung field
- heart shadow is larger
what is the systemic approach to interpreting a CXR
- Image quality: Penetration, Artifact, Inclusion, Rotation (PAIR)
- CXR Interpretation
- Air: Central airways, lung parenchyma
- Bones: Ribs, clavicles, spine, shoulder, scapulae
- Circulation: Heart, blood vessels and mediastinum
- Diaphragm and pleura
- Extra features: medical interventions, soft tissues
- Gastric Bubble/Free air
- Hilum
The degree to which X-rays have passed through the body
Penetration
what makes an Adequately penetrated image
- Vertebrae are slightly visible behind the heart
- Left hemidiaphragm should be visible to the edge of the spine
what are radiologic artifacts
Abnormal rotation of patient
Incomplete inspiration
Incorrect penetration
what are Patient Artifacts
Poor cooperation of patient
Movement
Clothing, hair, jewelry
Metal or implants in the body
Skin folds
Adipose or breast tissue
what does a rotation CXR look like?
- Spinous processes of the thoracic vertebrae should be at the midline of the posterior chest
- The medial ends of the clavicles should form a vertical line and should be equidistant from the midline
what would you see in an inclusion PA view CXR
- 5-7 Anterior Ribs - angled (PA)
- 10 Posterior Ribs - horizontal (PA)
- Costophrenic Angles
- Lateral edges of Ribs
what does the trachea/bronchi look like in CXR
- Visible in most good quality x-rays
- Contains air so lower density than surrounding structures resulting in a darker gray structure
- Trachea should be midline, straight and branches off to R/L mainstem bronchus at the carina
how to inspect the Lung Zones
- should be in a right-to-left pattern moving from the apex to the lung bases
- Always compare R/L and zone to zone
- Note any asymmetries and determine which is normal
which lung has 2 lobes (Upper and Lower) and which one has 3 (upper, middle, lower)
left
right
pleural covering separating the lower lobe from the upper lobe(s) in both lungs
Oblique (Major) Fissure
separates the R middle from upper lobe
Horizontal Fissure
what bones are visible on CXR
- Clavicles
- Ribs - pathology affects adequacy of inspiration
- anterior and posterior ribs are visualized - Scapulae
- Proximal humerus
- Vertebra
what diseases are you looking for in bones with CXR
fracture
arthritic changes
dislocation
metastatic pathology
How many ribs are seen anteriorly and posteriorly in the lung field ?
10 posterior
9 anterior
what part of the circulation is determined in relation to the total thoracic width
heart size
what is the Cardiothoracic ratio (CTR)
Cardiac Width : Thoracic width
CTR should only be assessed confidently if ?
“PA” view was acquired
what is an abnormal cardiac width
> 50% of total thoracic width
includes the borders of the heart and great vessels, as well as the spaces in front and behind the heart
contours
how should the contours of the mediastinum look like
borders should be sharp
what helps knowing these divisions allow us to make a more narrow differential diagnosis when there is a mediastinal mass
compartments/spaces of mediastinum
there is no tissue plane separating these compartments
what is the space in thoracic cavity between lungs?
what are its boundaries?
mediastinum
Posteriorly: thoracic spine
Anteriorly: sternum and costal cartilages
Laterally: mediastinal pleura
Superiorly: thoracic inlet
Inferiorly: diaphragm
Separates the thoracic cavity from the abdominal cavity
diaphragm
how should the diaphragm look like on a CXR
rounded, domed structure with a crisp white edge contrasted against the adjacent dark lung
often the R diaphragm will be slightly higher than L
what structures are almost superimposed on a lateral view.
The left and right hemidiaphragms
which hemidiaphragm blends with the heart and becomes indistinct
left
which hemidiaphragm can e seen up to the anterior chest wall
right
what should you compare when looking at diaphragm abnormalities
lateral and PA CXR
Formed by the hemidiaphragms and the chest wall
PA view should show sharp angles
what structures are being described
Costophrenic Recesses & Angles
what angle should the CPA be?
<30 degrees
what is Costophrenic “blunting”
CPA >30 degrees
Not visualized unless pathology is present
Lung markings should reach the thoracic wall
what is describing
diaphragm: pleural spaces
what extra features could be seen in CXR
- medical equipment
- soft tissues
- Breast - symmetry
- Nipple markings
- Pseudo-blunting of CPA’s due to rotation or large pendulous breast
Free air under diaphragm is indicative of?
perforated intestinal organ
Contains major bronchi and pulmonary vessels
what is this structure?
hilum
Hilar structures should be of same size, density, and position
which hilum is often higher than the other due to the anatomy
left hilum > right
a solidification of lung tissue with liquid or solid material that normally contains gas (air)
Consolidation
causes of Consolidation
- atelectasis
- infection/exudate
- pulmonary edema
- inflammatory
- exudate
- inhaled water
- blood
- tumor
an excessive amount of gas trapped in the alveoli of the lungs over a long period of time
lungs appear elongated and diaphragm is flattened
what is this condition
Hyperexpansion
cause of Hyperexpansion
loss of elasticity preventing expulsion of air
MC cause COPD
causes of Costophrenic Angle Blunting
- pleural effusion - MC
- pleural abscess
- hemothorax
- pulmonary embolism
- other lung disease in the lateral base of the lung
a collection of fluid in the alveoli of the lungs preventing adequate air exchange
Pulmonary Edema
causes of Pulmonary Edema
- Cardiogenic pulmonary edema - MC
- CAD, cardiomyopathy, valvular disease, HTN, CHF - Acute respiratory distress syndrome (ARDS)
- chest wall trauma, sepsis, pneumonias - Neurogenic pulmonary edema (NPE)
- head trauma, seizure, Subarachnoid hemorrhage (SAH) - Adverse drug reaction
- Pulmonary embolism
- Viral infections
- Lung injury
- pneumothorax, near drowning, smoke/toxin inhalation,
a tubular outline of an airway made visible by filling of the surrounding alveoli by fluid or inflammatory exudates
Air Bronchogram
causes of Air Bronchogram
- lung consolidation
- pulmonary edema
- non-obstructive pulmonary atelectasis
- severe interstitial disease
- neoplasm
- normal expiration
collapsed lung
occurs when air leaks into the pleural space
what is this condition called?
pneumothorax
causes of pneumothorax
idiopathic
chest wall trauma
lung disease
ruptured blebs
mechanical ventilation
Excess fluid builds in the pleural space
Pleural Effusion
causes of Pleural Effusion
Congestive heart failure
Kidney failure
Infection
Malignancy
Pulmonary embolism
Hypoalbuminemia
Cirrhosis
Trauma
an abnormal enlargement of the heart
cardiomegaly
causes of cardiomegaly
HTN
valvular disease
cardiomyopathy
pulmonary hypertension
pulmonary effusion
anemia
thyroid dysfunction
hemochromatosis (iron excess deposits in heart muscle)
amyloidosis (abnormal proteins build up in heart muscle)
Lung markings seen on imaging that represent thickened interlobular septa in the pulmonary interstitium
Septal “Kerley” Lines
2-6 cm oblique lines that course toward the hila
kerley A
1-2 cm horizontal seen in the periphery of the lungs (perpendicular to the pleural surface)
kerley B
same as Kerley B but coursing ventrally
kerley C
same as Kerley B but seen on the lateral CXR in the retrosternal air space
kerley D
causes of kerley lines
pulmonary edema, malignant lymphoma, viral/mycoplasmal pneumonia, pulmonary fibrosis, pneumoconiosis, sarcoidosis
an enlargement of the mediastinal structures
what are these specific structures
Mediastinal Widening
1. heart and cardiac vessels
2. other organs
- esophagus
- trachea
- phrenic and cardiac nerves
- the thoracic duct
- thymus
- lymph nodes of the central chest
what does this show?
R lung consolidation
what does this show?
hyperexpansion
what is this?
Costophrenic Angle Blunting
what is this?
pulmonary edema
what is this
Air Bronchogram
what is this?
pneumothorax
what is this
cardiomegaly
what is this
pleural effusion
what is this
mediastinal widening
