Lecture 18 - Imaging Flashcards
How do radiographs create an image (basic)?
X ray beam passed towards a plate detector
Structures that absorb the x-rays appear more white
What are the advantages of radiographs?
Quick
Cheap
Readily available
Low ionising radiation dose
What are the downsides to radiographs?
Low contrast
2D images
How does Ultrasound create images (basic)?
Handheld prob using sound waves?
What are the advantages of using ultrasound?
Cheap
No ionising radiation
What are the disadvantages of ultrasound?
Operator dependant (need to be skilled)
Limited by bone (too dense to pass through)
What is ultrasound useful for imaging?
Thyroid
Superficial soft tissue
What are the advantages of CT?
Quick
Readily available
What is the disadvantage of CT?
High does radiation
What are the advantages of MRI?
The best contrast
No ionising radiation
What are the disadvantages of MRI?
Slow
Expensive
Limited availability
Claustrophobic
Cant be done if have metal in body
What are radiographs typically used for in Head N Neck?
Minor skull trauma (when cant do CT)
Cervical spine trauma
Foreign bodies in neck
What are ultrasounds typically used for?
Thyroid evaluation
Superficial head and neck masses
Superficial infection
Carotid Doppler
What are CTs typically used for for Head N Neck?
Trauma
Acute focal neurological symptoms
Malignancy
Infection (retropharyngeal infections can go to mediastinum)
Angiographic imaging of arteries and veins
When may you want to do a CT for an adult?
Any sign of basal skull fracture
Focal neurological deficit
Multiple vomiting episodes
What are MRIs typically used for?
Imaging brain since it’s good and seeing difference between white and grey matter (tumour evaluation, epilepsy)
Cervical spinal cord trauma
Head and neck tumours
What are the 3 planes of sectioning?
Coronal (wearing a crown)
Transverse(slice like a cucumber)
Sagittal (split down middle)
What are the normal lines between the skull bones called?
Sutures
What is it called when bone is eroded by soft tissue?
Lyric soft tissue
Go to the last slide and label skull 1:
1 = frontal bone
2 = sphenoid bones
3 = frontal sinus
4 = ethmoid bone
5 = nasal bone
6 = maxilla
7. = cribiform plate
8 = parietal bone
9 = temporal bone
10 = foramen magnum
11 = occipital bone
Go to the last slide and label sutures image 2:
1 = coronal suture
2 = lambdoid suture
3 = squamous suture
Go to the last slide and label image 3:
1 = coronal suture
2 = Sagittal suture
3 = lambdoid suture
Go to the last slide image 4 and label the yellow and red strucutres:
Yellow = coronal sutures
Red = lambdoid sutures
Look at slide 24 for a normal facial radiograph
What is an orthopantomogram used to view?
Teeth problems
Mandibular problems
Look at slide 30, what is the abnormality?
No air in maxillary sinus
What is the abnormality on slide 31
Displaced right mandiiibular fracture
Non displaced left side mandibular fracture
Slide 32
What is the abnormality?
Right sided maxillary flor fracture
Soft tissue problems
Slide 33
Abnormality?
Left sided eyebrow sign (air around the orbit)
Slide 35
Abnormality?
Right sided mastoid fracture
Left sided fracture around carotid canal
Go to the last slide and label image 5 (vertebrae):
1 = pedicle
2 = vertebral body
3 = transverse foreman
4 = lamina
5 = spinous process
6 = superior articular facet
What vertebral body needs to be visible in the C spine for it to be considered a good image?
C7
Go to slide 41, what ligaments are the lines indicating?
Yellow = anterior spinal
Green = posterior spinal ligament
Blue = ligamentum flavum
What needs to be either side of the odontioid peg in a normal cervical radiograph?
Lateral masses
Look at slide 48:
What is the abnormality?
Fracture of C2
Go to the last slide, what is the image of?
Jefferson fracture
What is a Jefferson fracture?
Fracture of C1due to Axial loading
What are 3 spinal columns?
Anterior
Middle
Posterior
What is a limitation of Radiographs?
Can’t see ligamentous injuries
Look at the last slide at image 7, label the lobes of the brain:
1 = frontal lobe
2 = temporal lobe
3 = parietal lobe
4 = occipital lobe
What are the ventricles filled with in the subarachnoid space?
CSF
Look at the last at image 8:
Label the sections of the brain MRI:
Yellow = frontal
Green = temporal
Red = parietal
Blue = occipital
Purple = ventricle
What appearance does an Extradural haemorrhage produce on a CT?
Lentiform appearance
What causes an Extradural haemorrhage?
Middle meningeal artery rupture under pterion
How does a patient with an extra dural haemorrhage present?
Trauma
Loss of consciousness
Lucid interval where they’re ok
Then rapid deterioration
How does a subdural haemorrhage appear on CT?
Banana shaped/cresent shape
What causes a subdural haemorrhage?
Bridging veins break due to trauma causing bleeding into space between dura and arachnoid mater
What type of blood makes up a subdural haemorrhage?
Venous blood
How do we manage a subdural haemorrhage?
Anticoagulation (warfarin)
If small conservatively
Neurosurgical emergency
What is the pathology on the last slide CT 9:
Sub arachnoid haemorrhage
What are the normal causes of a subarachnoid haemorrhage?
Aneurysm/ruptureed vessel
Trauma
How do you treat a subarachnoid haemorrhage caused by trauma?
Correct Anticoagulatio
Further CT
Neurosurgical
What type of blood vessel is ruptured in a subarachnoid rupture / aneurysm?
Arterial blood
How does a subarachnoid haemorrhage present when caused by a rupture?
Central hyper density in subarachnoid space
Thunderclap headache
How are is a subarachnoid haemorrhage managed?
Neurosurgery
