Lecture 18- CXR part 2 Flashcards
synonym for assessing image quality
Rotation
Inspiration (lung volume)
Penetration
Exposure
inclusion: what do we need to see
- 1st rib
- lateral margin of ribs
- costophrenic angle
rotation: what do we need to see
- spinous process
- clavicles
inspiration (lung volumes) : what do we need to see
- X ray taken during inspiratory phase
- normal to see 5th to 7th anteiror rib at the midclavicular line
- problems with incomplete inspiration
- big heart
- increased lung markings
- exagerrated expansion
- obstructive airway disease (barrel chest)
penetrattion: what do we need to see
- degree to whicht he x-rays ahev passed through the body
- for adequate pentration
- vertebrae just visible through heart
- complete left hemidiaphragm is visible
the left hilar point is
higher up than the right hilar point
formed by the outer margins of the superior pulmonary vein and the descending pulmonary artery as they cross past each
lung zones
upper zone
middle zone
lower zone
*not very precise*
costophrenic angle vs recess
systemic approach to CXR evaluation
- Patient demographics
- Projection
- Adequate X-ray?
- Rotation
- Inspiration
- Penetration
- Exposure
- Airway
- Trachea
- Bronchi- hila
- Breathing
- Lungs
- Pleural spaces (costaphrenic angles and lung markings- need to come right out to the ribs)
- Lung interfaces
- Silhouette signs
- Circulation
- Mediastinum
- Aortic notch
- Pulmonary vessels- Hila
- Right heart border
- Right atrium
- Middle lobe interface
- Left heart border
- Left ventricle
- Lingula interface
- Mediastinum
- Diaphragm/ Dem bones
- Free gas under diaphragm
- Nodules
- Fracture/dislocation
- Mass
- Everything else
- Review areas
review areas
commonly missed pathology
Apices
pneumothorax
- Looking at the lung edge shows space in pleural cavity–>pneumothorax
Apices (2)
Right upper apex is hazy?
- Pancoast tumours are cancers that start in the top part of the lung (the apex).
what is this
- Mass behind heart- in left lower lobe
- Pleural effusion- can see meniscus
what are we looking at belwo the diaphragm
free gas within peritoenum
(make sure you are not looking at the stomach (look at right hemidiaphragm)
what is missing in this?
- Head of humerus missing
- Look at notes- amputation due to sarcoma
- Then spot mass in lungs- lung cancer
what are silhouette signs
Adjacent structures of differing density form a crisp silhouette
example of silhoutte signs
right heart bordewr
left heart border
paratracheal stripe
chest wall
aortic knuckle
loss of silhoutte contour can
locate pathology e..g. loss of silhouette sign
Loss of right heart border
Pathology in right middle lobe
Loss of left heart border
Lingula pathology
Loss of paratracheal stripe=
Mediastinal disease
Loss of chest wall=
Lung/pleura/rib pathology
Loss of aortic knuckle=
pathology in anterior mediastinum/upper lobe
example of an over exaggerated loss of silhouette sign
mediastinal shift
- Adequately centre image
- Look at
- Trachea
- Cardiac shadow
- Pushed or pulled?
pushed mediastinum (trachea and heart)
increased volume or pressure
pleural effusion and pneumothorax
pulled mediastinum shift (trachea and heart)
decrease volume or pressure
Pull: Loss of lung volume (Atelectasis, fibrosis, agenesis, surgical resection, pleural fibrosis)
reading a CXR is a description games
- Don’t just jump to a diagnosis
- Describe what you see and then formulate a diagnosis
- Generally describe CXR as:
- Shadowing
- Opacification
- Density
what is a pneumothorax
- Air trapped in the pleural space
- Spontaneous (primary) or as a result of underlying lung disease (secondary)
- Most common cause is trauma
- With laceration of the visceral pleura by a fractured rib
CXR pneumothorax
- lung edge measures more than 2cm from the inner chest wall at the level of the hilum, is said to be large
- tracheal or mediastinal shift away from the pneumothorax and depressed hemidiaphragm, the pneumothorax is said to be under tensions
- signs
- visible pleural edge
- lung markings not visible beyond this edge
CXR pleural effusion/ fluid
Be aware of supine CXR
- Collection of fluid in the pleura space
- Uniform white area
- Loss of costophrenic angle
- Hemidiaphragm obscured
- Meniscus at upper border
what is lobar lung collapse
volume loss within lung
causes of lobar lung collapse
-
Luminal
- Aspirated foreign material
- Mucous plugging
- iatrogenic
-
Mural
- Bronchogenic carcinoma
-
Extrinsic
- Compression by adjacent mass
- Generic findings of lobar lung collapse
- Elevation of the ipsilateral hemidiaphragm
- Crowding of the ipsilateral ribs
- Shift of the mediastinum towards the side of atelectasis
- Crowding of pulmonary vessels
sale sign
left lower lobe collapse
- Veiling opacity
- left upper lobe collapse
consolidation can be described as
dense opacification
e.g. loss of right heart border caused by middle lobe consolidation
consolidation is caused by
-
Filling of small airways/alveoli with stuff
- Pus- pneumonia
- Blood- haemorrhage
- Fluid- oedema
- Cells- cancer
space occupying lesions - SOL can be described in a number of ways
- nodule
- mass
- single vs multiple
nodule
SOL <3cm
mass
SOL >3cm
causes of SOL
- malignant
- primary
- metastases
- benign mass lesion
- inflammatory
- congenital
what can mimum space occupying lesiosn
- bone lesion
- cutaenous lesion
- nipple shaddow
example of space occupying lesion
- Asymmetry
- Mass in left lung
- >3cm
- Diaphragm is elevated lung cancer has invaded mediastinum which has caused phrenic nerve palsy
Cavitating lung lesion- fungating infection:
- Cavitating malignancy
- TB
- Septic emboli
Miliary nodularity
refers to innumerable, small 1-4 mm pulmonary nodules scattered throughout the lungs.
Should be able to pull these out with tweezers
- TB before proven otherwise
- Could be malignancy
CXR vs cancer
On first glance this looks normal. A few weeks later they come back for CT- they’ve got lung cancer. If you look back at the original it can be be seen
CTs- better for picking up cancers
- CT at a low dose used for screening
does CXR or screening chest CT (low dose) have more radiation?
CT
CT pulmonary angiogram
The computed tomography pulmonary angiogram (CTPA/CTPE) is a commonly performed diagnostic examination to exclude pulmonary emboli
Chest CT with IV contrast
- Contrast can enhance tumours
CT can be create images in both the
transverse and coronal plane
US and chest imaging
- Really bad a look at air in the lung
MRI and chest imaging
- Very motion sensitive
- So rarely used
- Can be used to look at mediastinum and the heart
Nuclear medicine- V/Q scan
- Less radiation
- For PE
- Not very good- most would choose CT
