Module 6: Pulse Sequences and MRA Flashcards
(11 cards)
On a T1 weighted image what are some tissues that appear bright (6 things)?
fat (adipose, subcutaneous, bone marrow), methemoglobin (intracellular/extracellular), melanin, fluid with protein, slow flowing blood, and of course gadolinium based contrast agents.
White matter of the brain is _____ compared to grey matter due to its shorter T1 relaxation times.
a) hypointense
b) hyperintense
c) indistinct
hyperintense
T/F on a T1 weighted image CSF has low signal.
True
On a T2 scan CSF & vitreous humor of the globe produce:
a) high signal
b) low signal
c) intermediate signal
a) high signal
On a T2 scan brain tissue (white and gray matter), nerves and muscles produce:
a) high signal
b) low signal
c) intermediate signal
c) intermediate signal
T/F on a T2 weighted scan air produces low signal
true
Subcutaneous fat has ____ signal on a T2 weighted scan:
a) high signal
b) low signal
c) intermediate signal
a) high signal
his has to do with modern MRI sequences using fast spin echo (vs. conventional spin echo). Fat molecules have an inherent low T2 relaxation time and are naturally coupled together. The coupling of fat molecules causes the T2 relaxation time to lengthen when it is bombarded with multiple 180 degree refocusing pulses, this is called ‘J-coupling’.
What weighting is used is often used to visualize periventricular white matter lesions such as multiple sclerosis and inflammatory diseases within the brain?
a) T1
b) T2
c) PD
c) PD
PD weighting has:
a) Long TE and long TR
b) short TE and long TR
c) short TE and short TR
d) Long TE and long TR
b) Short TE and long TR
Signal from fat is ______ on T1W scans because of its short T1-relation properties.
a) hyperintense
b) hypointense
a) hyperintense
For neuroimaging fat is ________ in T2W scans due to the multi-echo property of fast spin echo.
a) hyperintense
b) hypointense
hyperintense
