9.1 Radiology Of Chest 2 Flashcards
What details must you check before conducting a chest X-ray?
Patient details (name DOB Identification no.)
Date and time film was taken
Previous imaging (useful comparison)
Determine projection and adequacy of x-ray
What is the mnemonic RIPE used for?
To assess image quality
What does RIPE stand for?
Rotation
Inspiration
Projection
Exposure
How is rotation assessed in a chest x-ray?
The medial aspect of each clavicle should be equidistant from the spinous processes.
The spinous processes should also be in vertically orientated against the vertebral bodies.
How is inspiration assessed in a chest x-ray?
The 5-6 anterior ribs, including 1st rib
Lung apices, both costophrenic angles and the lateral rib margins should be visible.
How is projection assessed in a chest x-ray?
Note if the film is AP or PA: if there is no label, then assume it’s a PA film (if the scapulae are not projected within the chest, it’s PA).
How is exposure assessed in a chest x-ray?
The left hemidiaphragm should be visible to the spine and the vertebrae should be visible behind the heart.
What is the ABCDE approach when examining a chest x-ray
Airway Breathing Cardiac Diaphragm Everything else
Why is an AP chest x-ray not favourable?
As the heart silhouette is magnified, cannot accurately judge heart size
Scapula appear in the chest
Poor view of the lung bases due to magnified heart, can miss anthology there
How should lung volumes be when taking a chest x-ray?
Should be during inspiratory phase.
5th to 7th anterior ribs at Mid clavicular line.
How might lung volumes indicate pathology in an x-ray?
Incomplete inspiration = fewer the 6 anterior ribs visible at mid clavicular line. May be due to big heart, may show increased lung markings
Exaggerated expansion = greater amount of anterior ribs visible at the MCL. May be due to obstructive airways disease. Will also see flattening of the diaphragm
Why should a chest x-ray not be taken during expiration?
As fewer than 5 anterior ribs will be visible as lung volumes are reduced. Diaphragm raised. Less lung tissue visible
Which hilar point is higher?
The left hilar point appears higher than the right hilar point
What are lung zones?
3 divisions of the chest: upper, middle and lower.
Why is it important that costophrenic angles appear crisp and clear?
To ensure there is no fluid sat in the costophrenic recess, which happens in pleural effusion
What structures are assessed when considering airways?
trachea, carina, bronchi and hilar structures.
What structures are considered when assessing breathing?
lungs
Pleural spaces
Lung interfaces
(Compare and contrast against each side)
What structures are assessed when considering circulation?
heart size and borders
- right heart border (right atrium and middle lobe interface
- left heart border (left ventricle, lingula interface)
Mediastinum
Aortic arch
Pulmonary vessels (hila)
What structures are assessed when considering diaphragm?
assessment of costophrenic angles and cardiophrenic angles Free gas under diaphragm Nodules fracture/dislocation Mass
What structures are assessed when we are considering ‘everything else’?
Areas where pathology in commonly missed.
Apices = pneumothorax Thoracic inlet = mass Paratracheal stripe = mass/lymph nodes in mediastinum AP window = mediastinal lymph nodes Hila = mass/lymph nodes Behind heart = mass Below diaphragm = pneumoperitoneum/ mass Bones–allofthem! =Fracture/mass/missing Edge of films
If there is a space between the lung edge and the chest edge, what does that indicate?
Pneumothorax
What is a pancoast tumour?
A tumour of the pulmonary apex. Can spread to near by tissues such as ribs and vertebrae.
What is pneumoperitoneum?
Abnormal presence of air or other gas in the peritoneal cavity
What is a sarcoma?
A malignant tumour that starts in connective tissue such as in bone
What is the silhouette sign?
Crisp silhouette caused by structures of differing density lying next to each other. Lost if there is colsolidation or a mass
Loss of silhouette sign at the right heart border indicates?
Pathology of right middle lobe
Loss of silhouette sign at the left heart border indicates?
Pathology of the lingula
What is the lingula?
Downwards projection of the upper lobe of the left lung
Loss of silhouette sign at the paratracheal stripe indicates?
Mediastinal disease
Loss of silhouette sign at the chest wall indicates?
Pathology in the lung/pleura/rib
Loss of silhouette sign at the aortic knuckle indicates?
Anterior mediastinum/ upper lobe pathology
Loss of silhouette sign at the diaphragm indicates?
Lower lobe pathology
Loss of silhouette sign at the horizontal fissure indicates?
Anterior segment upper lobe
What do we need to assess when considering mediastinal shift?
Adequately centred image (rotation)
Look at trance and heart to see if it has been punched/ pulled by pathology
What causes a mediastinal shift?
Push = increase volume or pressure Pull = decrease volume or pressure
What might cause a pushed mediastinal shift?
Tension pneumothorax
Large pleural effusion
How do you know if substance in an x-ray is a fluid?
Has a meniscus
What might cause a pulled mediastinal shift?
Collapse of lung (white out with fluid and consolidation
Collapse of lobes
What causes a bronchus cut off sign?
A tumour sat in the bronchus, obstructing the lung. Can cause collapse and effusion followed by mediastinum shift
What words are used to describe a pathology of lung tissue
Shadowing
Opacification
Density
What is a pneumothorax (primary/secondary)?
Air trapped in pleural space
Primary = spontaneous
Secondary = as a result of underlying lung disease
What is the most common cause of pneumothorax?
Trauma with laceration of the visceral pleura by a fractured rib
What is a large pneumothorax?
Lung edge measures more than 2 cm from the inner chest wallat the level of the hilum
When is a pneumothorax said to be under tension?
Tracheal or mediastinal shift away from the pneumothorax and depressed hemidiaphragm
What signs are seen on an X-ray of a pneumothorax?
Visible pleural edge
Lung markings not visible beyond this edge
Why does a tension pneumothorax need to be urgently decompressed?
Needs aspiration. Massive pressure in thorax stops cardiac return. Stops blood circulation, cardiac arrest and death
What is a pleural effusion?
Collection of fluid in pleural space
How does a pleural effusion appear on a CXR?
Uniform white area
Loss of costophrenic angle
Hemidiaphragm obscured
Meniscus at upper border
Why can a CXR of a pleural effusion very depending on position of patient
In emergency situation patient may be supine, fluid doesn’t layer to form layer. Pleural effusion would look larger and hazy
What is lobar lung collapse?
Volume loss within lung
What causes lobar lung collapse?
Luminal (aspirated foreign material, mucous plugging, iatrogenic)
Mural ( bronchogenic carcinoma )
Extrinsic ( compression by adjacent mass)
What are the general findings on an CXR of a lobar lung collapse?
Elevation of ipsilateral hemidiaphragm
Crowding of ipsilateral ribs
Shift of mediastinum to the side of atelectasis
Crowding of pulmonary vessels
What pathology is a sail sign on an x-ray associated with?
Left lower lobe collapse
What signs are seen in left upper lobe collapse?
Preserved lung volume
Veiling opacity
Luftsichel sign
What is consolidation?
Filling of small airways/alveoli with stuff other than air.
What can cause consolidation?
Pus - pneumonia
Blood - haemorrhage
Fluid - oedema
Cells - cancer
How does consolidation appear on a CXR
Dense opacification
Volume preserved (possibly increased)
Air bronchogram
What are the different types of space occupying lesions?
Nodule = less than 3cm Mass = more than 3cm
What do we need to consider when looking at space occupying lesions?
Size (nodule/mass)
Single vs multiple
What may cause space occupying lesions?
Malignant - primary / metastasis
Benign mass lesion
Inflammatory
Congenital
Mimics - bone lesion, cutaneous lesion, nipple shadow
What commonly cause cavitating lung lesions?
Malignancy
TB
Septic embolisms
What are military nodules caused by?
TB
Metastatic malignancies
What should the cardiac index be?
Less than 50% on a PA
Heart should occupy less than half of the thoracic cavity
What are the advantages and disadvantages of CT scan?
Higher radiation dose than CXR
Clearer imaging as can use windows to view tissues of interest better
why might give contrasts in CT scans?
To view PEs
Why arent ultrasounds commonly used to image the lung?
As poor at looking at air
When is USS used to image lungs
For guidance for draining pleural effusions
Why are MRIs not used to image lungs?
As very time sensitive. Cant hold breath for long enough
When would we worry about radiation exposure?
Pregnant patients/ breastfeeding - breast tissue is much more radiosensitive
