Imaging Thorax Flashcards
(30 cards)
CXR interpretation order
- Name, DOB, date and time film taken, any previous imaging, type of imaging (plain film, CT)
- Image quality: RIPE
- RIPE –> Rotation(medial aspect of each clavicle equidistant from spinous processes, spinous processes vertically orientate against vertebral bodies),Inspiration(adequately inspirated (5-7 ribs), adequate penetration,Projection(AP vs PA), Exposure (left hemidiaphragm visible to the spine and vertebrae visible behind the heart)
- Systems/ structures –> ABCDEFGHI
ABCDEFGHI acronym for CXR?
Airway
Bones and tissues
Cardia
Diaphragm
Edges of pleura
Fields of lungs
Gastric bubble
Hila
Instruments and wires
How would you present a CXR using a structured approach?
- State type of image, notable demographics and presenting complaint if known
- state adequacy of film
- describe main abnormality –>
- appearance; patchy, focal, well rounded…
- Location –> split lung into “zones”- upper, mid and lower
- Review areas:
- lung apices
- the heart
- the diaphragm
- the bones and soft tissues
- any lines/ wires?
- State differential diagnoses based on your findings
- Say what you would like to do next
Name the main visible structures you may see on an Xray
Visible structures:
- Trachea
- Hila
- Lungs
- Diaphragm
- Heart
- Aortic knuckle
- Ribs
- Scapulae
- Breasts
- Bowel gas
Name some important obscured structures you may see on xray?
Sternum
Oesophagus
Spine
Pleura
Fissures
Aorta
Label the structures
- 1st rib –> remeber tends to wrap around
- Aortic knuckle
- Left upper lobe
- Aortopulmonary window
- Left heart border –> represents left ventricle
- left oblique fissure
- gastric bubble under diaphragm
- left lower lobe
- costophrenic angle
- right lower lobe
- right oblique fissure
- right middle lobe
- right heart border
- horizontal fissure
- right hilum
- right upper lobe
- right paratracheal stripe –> can be seen on most CXR, should not be wider than 4mm thickness, made from right wall of trachea, adjacent pleura of R lung and fat. If widened can be a sign of thyroid and parathyroid cancer and lymph node enlargement
- trachea
Surface anatomy:
Where can you find the left oblique fissure?
Where can you find the right oblique fissure?
Where can you find the horizontal fissure?
- Left oblique fissure –> Arises between spinous processes T3-T4, follows the 5th intercostal space laterally, follows the contour of the 6th rib anteriorly
- Right oblique fissure –> begins at T4 spinous process, 5th intercostal space laterally and follows the contour of the 6th rib anteriorly
- Horizontal fissure –> Arises from right oblique fissure –> follows the 4th intercostal space from the sternum and meets the oblique fissure as it crosses the 5th rib
What shape is the AP (aortopulmonary) window normally?
What traverse the AP window?
Why is this important?
AP (aortopulmonary window) is normally concave. It is the concave space inferior to the arch of the aorta and superior to the pulmonary trunk.
The most common reason for a straightened or convex lateral border is mediastinal lymphadenopathy.
Traversing the AP window:
- Left phrenic nerve
- Left recurrent laryngeal nerve
- Left vagus nerve
- Left bronchial arteries
- Ligamentum ateriosum (remnant of ductus arteriosus)
- Fat
- Lymph nodes
What is consolidation?
how does it appear on CXR?
Consolidation - any pathologic process that fills the alveoli with fluid, pus, blood, cells (including tumor cells) or other substances resulting in lobar, diffuse or multifocal ill-defined opacities.
.
What is lung/ lobar collapse?
Lobar collapse = signs of volume loss and absence of air bronchograms
Air bronchogram = air filled bronchi (dark) being made visible by the opacification of surrounding alveoli (grey/ white). Almost always caused by pathologic airspace/alveolar process, in which something other than air fills the alveoli.
What is atelectasis?
atelectasis is used generally for partial collapse, often unilateral affecting part or all of one lung.
What is the silhouette sign?
Why is it useful for indicating the site of pathology?
Usually different densities of adjacent structures causes a silhouette
Pathological loss of differentiation between two adjacent structures.
Used to localise areas of opacities, atelectasis or mass within the lung.
What is a useful way of remembering the imaging features of consolidation?
A2BC3
- A- Acinar rosettes“fluffy” appearance of the parenchyma distal to the terminal bronchiole (acini at the end of the terminal bronchiole filled with tissue/ fluid)
- A- Air bronchograms
- B - bat wing distribution
- C - confluent ill defined appearance
- C - consolidation - diffuse/ perihilar/ bibasal, lobar/ segmental, locular/multifocal
- C- changes occur rapidly
Is the image on the L collapse or consolidation?
- Can see this fissures, trachea is central, hilum still visible
- Consolidation over the R upper lobe.
Consolidation or collapse?
This is an example of L upper lobe lung collapse:
Trachea is deviated, general opacity over the left lung, loss of heart border, loss of aortic knuckle (obscured). Loss of silhouette sign, loss of contrast.
Left upper lobe collapse becomes thin sheet like appearance –> Veil sign
- Loss of left lower heart border, hilum are at the same level indicating something is pulling down, loss of silhouette sign.
- Know there are two lobes in the lung, left lower lobe collapse
- Called retrocardiac “Sail sign”
Diagnosis: Right middle lobe collapse this is a PA chest radiograph of a child.
Signs:
Lost the right heart border
The trachea is visible, child has inhaled a foreign body and it has caused right middle lobe collapse.
(due to angle of right bronchus foreign body has gone down R main bronchus).
Horizontal fissure lost, hilum lost.
Collapse vs consolidation?
Loss of silhouette sign?
Which lobe is affected?
Why should you be especially aware when you see this sign on a CXR?
Diagnosis: R upper lobe collapse
Called the golden S sign.
When this sign is seen you should be especially suspicious of a carcinoma. The mass can block the R upper bronchus, causing R upper lobe collapse. Lobe rotates backwards, causing backwards S shape.
What is the diagnosis in this image?
Are the hilar level?
Are the lung markings obvious?
What is the tx for this diagnosis?
- Hilar look level, Left should be higher than the right
- Lung markings generally seen well until the left upper lobe.
- Air compressing the lung down, due to the compression the hilar are at the same level.
-
Diagnosis: Tension pneumothorax
- If suspicious of tension pneumothorax clinically —> never wait for CXR
- TX: 14G cannula in the 2nd intercostal space, midclavicular line.
Is this ET tube placed correctly?
- This ET has entered the R main bronchus
- This is dangerous as will overinflate the R lung without allowing airflow to the L
Is this ET tube placed correctly?
- This ET tube is placed correctly, can see it following the trachea centrally up to the carina, both the R and L main bronchi are visible.
Why are ET tubes used?
How are they shown on CXR?
What is the risk?
What are the rules for placement?
- ET tubes are inserted into the trachea to allow artificial ventilation
- Radioopaque strip so that they are visible on CXR
- The risk = left lung collapse and hyperinflation of the R lung
Rules for placement:
- Ax mandible position in the CXR –> is the neck flexed, neutral (mandible over C5/C5) or extended?
- Desired position is 5 +/- 2cm above the carina if the neck is neutral
Flexed neck - 3cm (+/- 2cm)
Extended neck - 7cm (+/- 2cm)
What is the tube shown on this CXR?
Is it correctly placed?
This is a NG tube. It is not correctly placed, but actually going down the L main bronchus.
How can be make sure NG tube placement is safe?
Must request for special CXR to check the position –> must see the tip of the tube below the diaphragm.
The risk = feeding into the resp sx which can be disastrous
4 points to check:
1) Tube descends the thorax in the midline
2) Tube bisects the carina
3) Tube crossed the diaphragm in the midline
4) The tip sits below the diaphragm.
