Radiologist tools Flashcards
X-rays
- Strengths
- Weaknesses
Strengths
- Great spatial resolution
- Cheap and available
- Easy interpretation
Weakness
- Projectional
- Ionising
- Very limited soft tissue visual
Asses CXR
- Review areas
- Lung apex
- Behind the heart
- Costophrenic angle
- Periphery
- Shoulder joints
- Clavicular fractures
- Surgical empysema - Below diaphragm
Cardiothoracic ratio
Cardiac length/ thorax length
Normal= 0.5 on PA
- On AP, will be magnified
Pulmonary oedema
- Causes
- Features
Causes
- Left-heart failure
- Fluid overload: kidney failure, IV fluids
- PE
Features
- Consolidation around hilum
- If LVF= heart enlargement
- Fluid in fissures if it leads to effusion
- Upper lobe pulmonary diversion (upper lobe veins are as prominent)
Lung consolidation
- Causes
Occurs due to fluid in the alveoli (pus, water, blood, malignancy)
Causes - Pneumonia (lower lobe= right heart border still preserved) Multifocal causes - Pulmonary oedema - Diffuse pneumonia (immunocompromised) - Haemorrhage - Fat emboli - Lymphoma, sarcoid
Lung consolidation
- CXR features
Air bronchograms
Opacity
Pneumothorax
- Tension features
Mediastinal shift away from the site of pneumothorax
Pneumothorax
- Types and causes
Spontaneous
- Mainly affects males
Trauma
- Rib fractures
- Haemothorax
- Surgical emphysema
Iatrogenic
- Operation
- ventilation
- Drain
- Central line
Secondary - Emphysema - CF - Bronchopleural fistula -
Pleural effusion
- Causes
Transudate
- LVF
- Hepatic failure
- Nephrotic syndrome
Exudate
- infection
- Malignancy
- Pulmonary infarct
- Connective tissue disease
- Pancreatitis
Pleural effusion
- Features
Uniform opacity
Meniscus
No air bronchioles, obstruction of heart borders
Lost of costo-phrenic angle
Lobar collapse
- Features: RUL collapse, lower lobe collapse
RUL collapse
- It moves up and medially
- Horizontal fissure moves position
Middle and lower lobe expand in compensation
Elevation of hilum and hemidiaphragm
Lower lobe collapse
- Collapses downwards and inwards
- Dense triangle in medial lung base
Causes of increased density
- Normal mediastinum
- Mediastinum moving away
- Mediastinum moving towards
Normal mediastinum
- Consolidation
- Pleural effusion
- Mesothelioma
Towards
- Lung collapse
- Pneumonectomy
- Lymphangitis
Away
- Pleural effusion
- Diaphragmatic hernia
Causes of small bowel obstruction
Hernias
Gallstone ileus
Post-surgical adhesions
Crohn’s adhesions/ strictures
Volvulus
Sizes for small bowel obstruction
- Prox jejunum
- Mid small bowel
- Ileum
Prox jej
- >3.5cm
Mid-small bowel
- >3cm
Ileum
- >2.5cm
Causes of large bowel obstruction
Large bowel cancer
Diverticulitis
Hernia
Constipation
Fecaloma/ Fecal impactation
Volvulus (sigmoid, caecal, transverse)
Contrasts in plain films
Barium studies
IVUs
Apple core lesion in barium indication
Large bowel tumour causing a stricture
Strengths and weaknesses of CT
Strengths
- Cross-sectional
- Good spatial resolution
- Widely available
Weakness
- Ionising radiation
- Limited soft-tissue diiffentiation
Ultrasound
- Strengths
- Weaknesses
Strengths
- Non-ionising
- Multiplanar
- Dynamic
- Doppler
Weakness
- Operator-dependent
- Can’t see through bone/ gas
MRI
- Strength
- Weaknesses
Strength
- Non-ionising
- Multiplanar
- Amazing soft tissue contrast
- Reproducible
- Non-operant dependent
Weaknesses
- limited availability
- Magnetic field
- Expensibe
- Can’t see gas/ calification
MRI contraindications (10)
Cardiac pacemakers
Implanted cardiac defibrillator
Aneurysm clips
Carotid artery vascular clamp
Insulin/ infusion pump
Nuclear medicine
- Strengths
- Weakness
Strength
- Functional information
Weakness
- Very limited anatomical info
- Radiation
X-rays risk in pregnancy
Exposure >5 RAD (high exposure)
- Eye damage
- Cerebral development
CXR= 60mrad
CT chest- 800 mrad
