Fr - Brain radiology Flashcards
… is the modality of choice in the acute setting for especially trauma and stroke
CT
What are beam-hardening artefacts?
When the CT cannot discern between soft and hard tissues there’s kind of a fading effect, this is called a beam-hardening artefact
Where can we see beam-hardening artefacts? (2)
Skull base and posterior fossa
Hounsfield units is a (technical/tissue) property
Tissue property
Why is it hard for CT to image soft tissues?
Because the Hounsfield units of WM and GM are close to each other
What does CT stand for?
Computed tomography
Intravenous iodinated contrast for contrast-enhanced computed tomography is (hypo/hyper)dens
Hyperdense
What is intravenous iodinated contrast used for in contrast enhanced computed tomography?
To help to enhance visibility and discrimination between healthy and affected tissues
How is CT computer reconstructed? How can it image small lesions? Explain
If you are unhappy with what you see, you can shift the HU to evaluate different tissues better or worse. It has its limitations, for examples small lesions, but you can increase visibility with contrast agent with iodine. Iodine is denser than our normal blood and thus gives it higher HU so we can see the vessels better.
… is the modality of choice for brain lesions characterisation
MRI
T1 weighting: (low/high): Fat
High
T1 weighting: (low/high): Water
Low
T1 weighting: (low/high): bone
Low
T1 weighting: (low/high): Blood
High
T1 weighting: (low/high): Gadolinium enhancement
High
