Radiology Flashcards
(32 cards)
CXR - Checklist
PA/AP radiograph, name, age, presenting complaint, trachea, mediastinum, hilum, lung fields, cardiophrenic and costophrenic angles, the diaphragm and bones and soft tissues.
CXR - Introduction
- This is an AP/PA chest radiograph of ‘name’ (or adult male or female if no patient details) who is ‘age’ years of old and presented with ‘presenting complaint’ (ideally CXRs are posterior-anterior).
Comment on quality:
- Is there full inspiration? – Diaphragm should be at the 6th rib level anteriorly.
- Is penetration good? – You should just be able to see the lower thoracic bodies through heart.
- Is the patient rotated? – The spinous processes should be midway between the clavicles.
- Say ‘the patient has taken a full inspiration, is not rotated and the film is well penetrated’
CXR - Mediastinum
Check the trachea is central then move down left side to check the aortic arch, the left pulmonary artery and the left heart border.
Look at the heart – should be 2 thirds on the left, 1 third on the right and take up no more than 50% of the thoracic cavity (if PA) (the left border of the heart is the left ventricle and the right border is the right atrium).
Then move up the right side to look at the ascending aorta followed by the superior vena cava.
Mediastinum - Tracheal Deviation
A tension pneumothorax or pleural effusion push the mediastinum away.
Whereas a lobar collapse (volume becomes small) pulls the mediastinum *towards it. *
Medistinum - Cardiomegaly
Can only comment on a PA radiograph – the most common cause is cardiac failure but can also be caused by pericardial effusion or cardiomyopathy.
Remember the signs of left heart failure – A – alveolar oedema (bat wing appearance – peri-hilar shadowing), B – Kerley B lines (interstitial oedema – horizontal lines from the pleural edge), C – cardiomegaly, D – dilated prominent upper lobe pulmonary veins (diversion) and E – pleural effusion.
CXR - The Hilar
The normal structures in this area are the pulmonary vessels, the main bronchi and lymph nodes.
Area will appear abnormal if there is lymphadenopathy or a primary tumour.
Check the aorto-pulmonary window on the left – obliterated where there is lymphadenopathy.
Hilar Enlargement
Pulmonary artery (hypertension due to mitral valve disease or PE), main bronchus (malignancy) or the lymph nodes (infection, carcinoma, lymphoma or sarcoidosis).
CXR - Lung Fields
Start at the apex and compare right and left sides as you work down the fields.
Lung Field - Pneumothorax
One half of the lung appears black and the edge of the collapsed lung should be visible. Look for a cause e.g. a fractured rib and for any associated surgical emphysema.
Is it a tension pneumothorax – medical emergency as venous return is decreased = cardiac arrest. If you see a pneumothorax either say there is no shift in the mediastinum so not a tension pneumothorax or the mediastinum is shifted so this is a medical emergency and I would insert a large bore cannula into the pleural space – 2nd intercostal space in the **mid-clavicular line. **
Lung Fields - The Air Spaces
Can fill with fluid in pulmonary oedema, pus in infection = consolidation, blood in Goodpasture’s disease or tumour cells in alveolar cell carcinoma.
The alveoli fill first and the bronchi remain air filled so stand out as dark lines surrounded by white = air bronchograms.
Lung Fields - The Interstitium
Surround bronchi, vessels and alveoli. Reticulo-nodular shadowing can be caused by fluid accumulation (in pulmonary oedema or lymphangitis – in breast malignancy) or inflammation leading to fibrosis in industrial lung disease e.g. fibrosing alveolitis.
Lung Fields - Collapse
Caused by proximal obstruction (neoplasm, mucus plug or foreign body) and causes loss of volume (unlike consolidation or airspace shadowing) – mediastinal shift towards the collapse, the hilum and horizontal fissure will be pulled towards the collapse, the remaining lung has to expand so appears darker and there may be evidence of proximal obstruction.
To identify site of collapse look for loss of a clear border between **lung and adjacent structures. **
Lung Fields - Complete Opacity of One Lung
Could be due to a large area of consolidation, pleural effusion (fluid, pus or blood), complete collapse of one lung or post pneumectomy.
Lung Fields - Pleural Effusion
There is a fluid level and meniscus and the mediastinum is shifted away.
Lung Fields - Nodules
Can be small <5mm – miliary TB, some infections, sarcoid, metastases (usually bigger), pneumoconiosis (coal dust inhalation).
Can be large >5mm – metastases (from the thyroid, breast, GI tract, kidneys or testes) or inflammatory nodules (RA or Wegener’s).
Single nodules can be caused by infection e.g. TB, primary malignancy or solitary metastases.
CXR - Diaphragm
Look at the costo-phrenic and costo-cardiac angles and check no air underneath.
CXR - Bones and Soft Tissues
Check breast shadows are present and no fractures or dislocations.
CXR - Review Areas
ABC – apices, behind heart, breasts and soft tissues and both phrenic angles.
CXR - Summary
The trachea is not deviated and the mediastinum is not displaced. The mediastinal contours and the hila appear normal.
The lungs appear clear with no pneumothorax. There is no free air under the diaphragm. The surrounding bones and soft tissues also appear to be normal.
I have not yet identified an abnormality so I will look through my review areas.
AXR - Checklist
Name, age, symptoms, is the film adequate, bowel loops, calcification, bones and devices.
AXR - Introduction
Name and age of patient, date and time of radiograph, AP or PA film and quality of the radiograph – is it well penetrated (see spinous processes) and is the whole abdomen visible (includes inferior pelvis)?
AXR - Bowel Obstruction
In small bowel obstruction there are dilated loops of bowel in the centre of the abdomen which have valvulae conniventes – the entire width of the bowel.
- Small bowel causes – commonly adhesions following previous abdominal surgery or due to obstructed hernia or paralytic ileus and should be investigated by a CT scan.
In large bowl obstruction there are dilated loops around the outside and haustra are not all the way across.
- Large bowel causes – carcinoma commonly of the rectum or sigmoid colon, IBD, large diverticular, volvulus or paralytic ileus and should be investigated by CT scan.
AXR - Sigmoid Volvulus
Occurs in elderly with chronic constipation. Apex is in the pelvis and the caecum is visible so you know it’s a sigmoid = coffee bean sign.
Treatment – resuscitation and decompression of the sigmoid with flatus tube or flexible sigmoidoscope.
AXR - Toxic Megacolon
There is severe dilatation (>6cm) of the colon, there are no visible haustra due to oedema, thumb printing is visible (again this is due to oedema).
There is a high risk of perforation.
