Chapter 11 Flashcards
Scar tissue enhances in the lumbar spine shortly after the injection of contrast (T or F)
true
Select all of the following that were discussed as possible MR contrast agents in the text.
Dilute barium solutions
Gadolinium
Mango juice
Blueberry juice
Choose all of the following that enhancement agents can be useful in detecting
Infarction
Tumors
Infection
Inflammation
When using gadolinium, the T1 relaxation time of the water is reduced so enhancing lesions (such as tumors associated with free water) appear bright on a T1 weighted image. (T or F)
True
Which sequence would be used to best visualize metastatic lesions in the bone?
Fat saturation techniques with contrast
Gadolinium chelates are ferromagnetic.
False
They are paramagnetic
On a T1 weighted pre-contrast image, fat appears _____ and water appears _____.
Bright, Dark
All gadolinium contrast agents have the same ‘relaxivity’. (T or F)
False
Gadolinium element is ________ and gadolinium chelate contrast media is ________.
Ferromagnetic/paramagnetic
T1 time, T2 time
intrinsic
pulse sequence type
extrinsic
There are no known contraindications to gadolinium contrast. (T or F)
False
Gadolinium cannot cross the intact blood-brain barrier (BBB). (T or F)
true
however it can pass through breakdowns in the BBB, hence why it is so useful in detecting pathology in the brain and spinal cord.
After gadolinium administration, it is recommended that which images are acquired?
Multiple T1 weighted images
Enhanced MR images are evaluated for sensitivity and specificity, where sensitivity is ________ and specificity is ________.
The ability to detect the lesion/the ability to classify the lesion
Gadolinium cannot cross the ___ blood-brain barrier; however, gadolinium is valuable in imaging the CNS because of its ability to pass through ___ in the blood-brain barrier.
intact, breakdowns
TRUE or FALSE: Gadolinium can be used as a T1 and a T2 enhancement agent.
True
What is the recommended dose of gadolinium?
- 1 mmol/kg
0. 2ml/kg
Which of the following are contrast agent helpful in detecting
inflammation infarction contrast-enhanced MRA tumors post operation spinal surgery infection
TRUE or FALSE: Breast lesions that “wash-in” and “wash-out” rapidly are thought to be malignant.
True
TRUE or FALSE: It is acceptable to inject every patient with a standard dose of 10mL.
true and false
TRUE or FALSE: To comply with the ACR recommendations, a facility must have a doctor present during an injection of any contrast agent.
True
Which is true concerning NSF?
symptoms may not present for several days-weeks
fatal condition, no cure
bark-like skin condition
affects other organs, too
As an element, gadolinium is ___; however, when used as a contrast agent gadolinium is ___.
ferromagnetic, paramagnetic
how do lesions appear w gad on T1
bright lesions
how do lesions appear w gad on T2
dark lesions
Which series is usually performed after contrast injection?
T1
helium
may be used for imaging of the lung
manganese
may be used for liver
blueberry and mango juice
make bowel dark on T2 images
dilute barium
make bowel bright on T1 images
air
given via rectum to see prostate or uterus
Why is timing essential when imaging the liver seen on first pass
malignant lesions seen
Why is timing essential when imaging the liver second pass
liver and lesion are hypointense
Why is timing essential when imaging the liver third pass
benign lesions seen
magnetic susceptiblity
ability of external MF to affect the nucleus of an atom or magnetize it
relaxivity
effect of a substance on its relaxation rate
chelate
bound to other chemicals
perfusion
delivery of blood to tissues
half life for gadonlinium for pt with normal renal function
approx. 2 hours
Gd-BOPTA
has higher relaxativity than gad
initially enhances on post op pt
scar
enhances after approx 30 minutes on post op pt
disc
intrinsic
T1 time, T2 time, PD of a tissue
extrinsic
TR, TE, TI, flip angle
parameters which can not controlled
instrinsic
parameters which can be controlled
extrinsic
sensitivity
ability to detect a lesion
specificity
ability to classify a lesion
relaxivity
effect of substances on relaxaivity rate
chelates
affinity for metal ions
perfusion
delivery of blood
chelates
binds to sites of the metal ions, increases safety
Biological half life of gadolinium
less than 2 hours
why check for renal insufficiency
NSF
