chest and respiratory system Flashcards
CT chest - plain / low dose
coverage - lung apices to bases
indications - varied, but often includes; lung nodule follow up, cystic fibrosis and bronchiectasis screening
not useful for: initial ? cancer staging, vascular pathologies such as aortic dissection / pulmonary embolism
CT chest - with contrast
coverage - lung apices to bases, but will often be accompanied by an abdo/pelvis scan
scan delay - 30 seconds (arterial) or 70 seconds for general scanning (60 for pleura)
indication: primarily cancer investigation
not suitable for: initial vascular pathologies such as aortic stenosis / pulmonary embolism (delay is too long)
CT chest - aortic angiogram
coverage - thoracic aorta
scan delay - 30 seconds usually bolus tracked from the ascending aorta (monitored from level of aorta arch)
indications - aorta aneurysm / dissection or bronchial artery abnormalities
not suitable for: can investigation as tumour contrast uptake often delayed
CT chest - pulmonary angiogram
coverage - lung apices to bases
scan delay - bolus tracked from the pulmonary trunk as very dependant on cardiac output (monitored from the level of the carina)
indications - used almost exclusively for ? pulmonary embolism
MRI
not as useful as CT in assessing lung tissue due to the general lack of hydrogen. can be used to characterise tumours / differentiate from normal lung tissue. also used when patients are allergic to iodinated contrast
fluoroscopy
wide variety of applications:
barium swallow
tracheal / bronchial stents
brachytherapy
bronchial artery embolism
ultrasound
being used increasingly in A&E and critical case
generally used to investigate:
pneumothorax
pleural effusion
pneumonia
pulmonary oedema
guidance for chest drain insertion
central line / CVP
- used for drug administration / blood sampling
- CVP lines used to monitor central venous pressure
- used primarily in the acute setting
- inserted in the internal jugular vein mainly, but also the subclavian / femoral veins
- tip should sit in the distal 1/3 of the superior vena cava / cavoatrial junction
dialysis line
- usd to facilitate haemodialysis
- inserted in the internal jugular vein mainly, but also the subclavian / femoral veins
- similar to a CVC, however has 2 separate lines from extracting / returning blood
-usually tunnelled under the skin to exit by the shoulder to maintain distance between the access and insertion sites for infection control - tip should sit in the distal 1/3 of the superior vena cava / cavoartial junction, but often sits in the right atrium due to increased need for blood flow
implanted port
- inserted in the internal jugular vein mainly, but also the subclavian / femoral veins
- similar to a CVC but with no external connection. access is gained by inserted a special needle through the skin into the port section
Peripherally Inserted Central Catheter
- similar to a CVC but inserted into a vein in the upper arm
- used to facilitate medium term IV access
- more often XR confirmation is not required as ECG guidance is used to determine tip position
Extracorporeal Membran Oxygenation
- life saving method of oxygenating blood when the heart has failed
- large pipes inserted into a vein / artery or directing into the heart
- when imaging we need to consult with the supervising nurse before interacting with these patients
pacemaker / ICD
- inserted through the subclavian vein
- leads are attached to the internal surface of the hear
- leads are connected to a box that sits under the skin
stents
- can be in any artery / vein
- appear like a metal cage on XR
- used to treat stenosis or leaking of a vessel
valves
- surgical replacement valves will appear like a metal ring
- will also be accompanied by sternal wires to close the chest after surgery
Left Ventricular Assist Device
- essentially an artificial pump for the left ventricle. implanted directed into the heart, usually for patients waiting for heat transplant
- there’s a magnetic component inside that causes gridline like interference on your detector
drains
- can be placed anywhere in the body, but in the chest to drain; pneumothorax, pleural effusion, infective collections and haemothorax
- usually requires a chest XR post removal to check for pneumothorax
shunts
- used to drain CSF from the brain ventricles
can be VA (atrial), VP (peritoneal) or EVD (external)
endotracheal tube
- artificial breathing tube attached to a ventilator
- can be inserted through the mouth or through a hole cut in the trachea (tracheostomy)
- tip should sit above the carina to ensure adequate ventilation to both lungs
nasogastric tube
- used to administer nutrients to those unable to eat
- usually inserted through the nose > oesophagus > stomach
- should bisect the carina
- should cross the diaphragm
- tip should lie in the stomach under the left hemidiaphragm
- in most cases only required XR confirmation is unable to aspirate low pH contents from it to confirm stomach acid presence
pneumothorax
- abnormal collection of air in pleural space between the lung and chest wall
- symptoms include sudden onset of sharp one-sided chest pain and SOB
- in a minority of cases the amount of air in the chest increases when a one-way valve is formed by an area of damaged tissue = tension pneumothorax
spontaneous pneumothorax
- primary - most common in young males, occurs in the absence of lung disease or traumatic injury, chest pain and SOB are symptoms
- secondary - occurs in the presence of lung disease and not due to traumatic injury
- traumatic - may be due to injury or also surgical intervention
haemothorax
- collection of blood in the pleural space and may be caused by blunt or penetrating trauma
- will appear similar to pleural effusion
- confirmation required through CT / needle aspiration / drainage
pleural effusion
- excess fluid accumulation in the pleural cavity
- approx. 200ml require until effusion is visible on XR
- pressure of fluid can impair breathing
- can be due to build up of different fluids
atelectasis (collapse)
- incomplete expansion due to alveolar collapse
- can be anywhere in the lung, in any pattern
- can witness mediastinal shift
emphysema
- associated with hypertension
- mucus in bronchiole, enlarged alveoli and fewer capillaries
bronchiectasis
- long term condition
- abnormal widening of the airways (up to 4x size)
- increase mucus production
- symptoms include a persistent productive cough and SOB
- can be exacerbated by chest infections
- antibiotics and physio to treat
consolidation
- non-specific airspace opacification
- alveoli and terminal bronchioles filled with dense material e.g. pus (pneumonia), fluid (oedema), blood (haemorrhage), cells (cancer)
- dense and white appearance
- presentation dependent on the underlying cause but generally includes SOB, productive cough, fever, weight loss
COVID -19
- highly contagious form of SARS (severe acute respiratory distress syndrome)
- caused around 7 million reported deaths in the pandemic
- 770 million confirmed cases
- diagnosis through PCR testing
pulmonary oedema
- abnormal fluid accumulation in the lungs which collects in the alveoli
- affects ability for gas exchange to occur
- cardiogeni vs. non-cariogenic
- low oxygen saturations
nodules
- found on 1 in 500 chest XRs
- lesion 3cm or less
- benign - slow growing, smooth and regular shape
- malignant - fast growing, irregular shape, rough surface, heterogenous appearance
non-small cell lung carcinoma
- largest group of lung malignancies
- adenocarcinoma commonly seen in smokers, slow growing starting in cells which would normally secrete mucus
- squamous cell carcinoma - develops from cells that line the airways
large cell carcinoma
- 10-15% of lung cancers
- appear in nay part of the lung
- grows and spreads quickly
small cell lung carcinoma
- starts in the bronchi
- grows and spreads quickly
- difficult to differentiate on imaging
