Final MRI Protocols Flashcards
(44 cards)
What is included in patient preparation for any MRI examination?
Surgery?
Implants? When, where?
Shrapnel?
Pre-cannulation?
Changing into a gown
Remove make-up
Secure or remove piercings and jewellery
What is a routine brain sequence?
3 plane localiser - at isocentre, 5 images, T1FS
Sagittal T1 - for midline, full head ant. and post. to temporal bones, 4-5mm slices
Axial T2 - survey pathologies and fluid structures, superior skin edge to foramen magnum, 4-mm slices
Axial FLAIR - survey pathologies especially grey and white matter, superior skin edge to foramen magnum, 4-5mm slices
Axial DWI - gold standard for strokes, superior skin edge to foramen magnum, 4-mm slices
Axial Gradient - for magnetic susceptbility (blood or calcium products), superior skin edge to foramen magnum, 4-5mm slices
What is the protocol for a brain ?tumour ?
Routine brain
Axial T1 pre contrast with hand injection of Gad
Axial T1 + C
Coronal or sagittal T1 C - orthogonal view
Optional: 3D T1 + C- for pre-operative planning or intra-operatively
Name an operation that would need further discussion if listen on an MRI safety questionnaire?
Brain surgery, ear surgery, brain aneurysm treatment, insertion of active implant
What are the 5 common routine brain sequences?
Sagittal T1, axial T2, FLAIR, DWI, GRE
A FLAIR sequence in the brain is very good at differentiating between —- and —-
Grey and white matter
A GRE sequence in the brain is sensitive to what blood breakdown product?
Haemosiderin
What are the common post contrast brain sequences?
Axial T1+C
What are the common post contrast brain sequences?
Axial T1+C and Cor T1+C
What is TOF MRA?
Time of flight MR angiography
Does not use IV Gad
Is a 3D sequence
Using MIP
Good for large blood vessels
What is MRV?
MR venography
Using IV Gad
Can be added to routine brain
Is a 3D sequence
Using MIP
Good for large blood vessel
What sequence should be used for the IAMs?
T2 thin slice
May be 2D or 3D
Done over internal and external AM
Axial and coronal views
When a referral says ?acoustic neuroma, what MRI sequences should be performed?
A routine brain scan and IAMs sequence
What does an IAMs sequence demonstrate?
Acoustic neuroma
7th and 8th cranial nerves
What sequences should be done for the pituitary?
T1 coronal and sagittal
T2 coronal and sagittal
Post contrast T1 coronal and sagittal
What are some limitations of a pituitary sequence?
A small FOV mean result in phase wrap
Therefore, use a large FOV and focus on the smaller ROI
What sequences should be done for a referral with ?microadenoma ?
T1 coronal and sagittal
T2 coronal and sagittal
T1+C coronal and sagittal
Dynamic post contrast coronal
What is DTI used for?
Diffusion tensor imaging shows the white matter tracts in the brain. It is used for mapping to aid in pre-op planning
What is the relationship between multiple sclerosis and MRI?
MRI is the gold standard for imaging MS
What is the relationship between tumour operations and MRI?
MRI may provide additional information or better pre-op planning for tumours
What sequences best visualise MS?
T2 FLAIR
What sequences best visualise a new stroke?
DWI will demonstrate the stroke with a high signal
ADC will demonstrate the stroke with a low signal
What sequence best shows mets?
T2 FLAIR
What is the appearance of metastatic melanoma?
T1 - hyper-intense secondary to haemorrhage or melanin
T2 - hypo-intense
T1+C - peripheral rim pattern enhancement or a diffusely heterogenous pattern