Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
122 Cards in this Set
- Front
- Back
|
What does GBMCA stand for? |
Gadolium based magnetic resonance contrast agent. |
|
|
Why is GMBCA used? |
To increase the signal intensity of certain tissues on MRI images. |
|
|
How does GBMCA increase the signal intensity of certain tissues? |
It shortens the T1 relaxation time. |
|
|
Free water molecules (associated with lesions and tumors) tumble much __________ than Larmor, resulting in ________ relaxation times. |
Faster, long. |
|
|
Using gadolinium chelates, fluctuations happen near ___________ and therefore spins from neighbouring water molecules are sped up and relaxation times are ___________. |
Larmor frequency, reduced. |
|
|
Gadolinium creates a __________ effect on local magnetic fields. |
Positive |
|
|
Gadolinium is an earth metal ion called... |
Trivalent lanthanide. |
|
|
Gadolinium is ideal because it has ___ unpaired electrons. |
7 |
|
|
The unpaired electrons have a magnetic moment that is ____________ times that of a hydrogen proton. |
500,000 |
|
|
The contrast will actually shorten ___________ relaxation times during the scan. |
Both the T1 and T2. |
|
|
T1 weighted images will have to be run _________ and the same scan __________ to accurately evaluate the enhancement. |
Pre-GAD and post-GAD. |
|
|
The raw earth metal element. |
Gadolinium |
|
|
A generic name for gadolinium based contrast agents. |
Gadopentate dimeglumine. |
|
|
Brand name GBMCA. |
- gadovist - magnevist - omniscan - prohance |
|
|
Chelate used for binding MR contrast. |
Diethylene triaminepentaacetic acid (DTPA). |
|
|
Gadolinium in its native state is highly... |
Toxic |
|
|
Tissues with a natural affinity for metals can become binding sites, including the... |
- liver - spleen - lungs |
|
|
What does DTPA stand for? |
Diethylene triaminepentaacetic acid. |
|
|
DTPA binds ___ of ___ sites of gadolinium. |
8 of 9 |
|
|
The 9th site of gadolinium is left free for the approach of... |
Water molecules. |
|
|
In a patient with normal renal function, the half life of Gd is ___ hours. |
2 |
|
|
Magnevist Chelate |
Gadopentate Dimeglumine (GD DTPA) |
|
|
Prohance Chelate |
Gadoteridol (GD HP-DO3A) |
|
|
Omniscan Chelate |
Gadodimide (GD DTPA-BMA) |
|
|
Gadovist Chelate |
Gadobutrol (GD BT DO3A) |
|
|
Viscosity |
Thickness of the contrast. |
|
|
GD-DTPA (Magnevist) has a ___________ viscosity, therefore will require _______ pressure when injecting. |
Higher, more. |
|
|
Measure of a compound's ability to cause osmosis (movement of molecules through membrane). |
Osmolality |
|
|
Osmolality is measured in... |
Osmoles per kg of water. |
|
|
Normal osmotic balance = |
290 mOsm/kg |
|
|
If an injected material disrupts the normal osmotic balance, the patient can go into... |
Hyper-osmotic shock. |
|
|
The effect of a substance on relaxation rate. |
Relaxivity |
|
|
Gd-BOPTA (Multihance) is an example of a _______ relaxivity agent. |
High |
|
|
Gadolinium agents are _______________ contrast agents known to cause fewer and less severe _____________. |
Non-iodinated, reactions/side effects. |
|
|
Overall, it is estimated that _______% of people will have a reaction to gadolinium based contrast. |
4-10% |
|
|
Mild Reactions |
Itching, coughing, sneezing, warmth, altered taste, rash, urticaria, dizziness, shaking, nasal congestion, flushing, pallor, chills, sweats, swelling of eyes/face. |
|
|
Usage Criteria |
1. Significantly decrease magnetic relaxation for mobile protons in target tissue. 2. Biologically compatible with tissue. 3. Combined with carrier molecule. 4. Rapidly excreted. 5. No patients with renal failure (GFR<30). |
|
|
What to do before a Gd exam. |
1. Be aware of complications. 2. Know patients prior reaction. 3. Assess risk/benefit. 4. Adopt preventative measures. 5. Prepare to manage adverse reactions. |
|
|
Headache Stat |
Less than 5% |
|
|
Nausea Stat |
4.1% |
|
|
Vomiting Stat |
2% |
|
|
Dizziness Stat |
1.5% |
|
|
Rash or Hypotension Stat |
Less than 1% |
|
|
Anaphylactic Stat |
Less than 0.01% |
|
|
With a severe contrast reaction, what is the first step that should be taken? |
Call a code and follow appropriate emergency procedure. |
|
|
For minor reactions, inform the ______________ or the _______________. |
Radiologist or nursing staff. |
|
|
Pharmaceutical intervention for severe reactions include. |
Epinephrine |
|
|
Pharmaceutical intervention for mild reactions include. |
Benadryl or antihistamine. |
|
|
After a contrast reaction, the radiologist will want to keep the patient in the department until they are confident the patient is stable. This can take up to ___ hours. |
2 |
|
|
It is good practice and recommended that individuals who have had contrast (and even no reaction) to have them wait ___________ before releasing. |
Half an hour. |
|
|
What does NSF stand for? |
Nephrogenic Systemic FIbrosis |
|
|
Patients with NSF experience ___________ and ___________ of skin that develops over a period of days. |
Swelling and tightening. |
|
|
NSF can also affect the function of body ________ when it progresses. |
Organs |
|
|
NSF has only occurred in people with... |
Reduced kidney function. |
|
|
No cases has been identified prior to ________ and no cases have been reported after _______. |
1997 and 2009 |
|
|
Those with decreased renal function demonstrate an approximate ____% incidence rate. |
3% |
|
|
The odds of NSF increase with _________ dosing over short periods of time or _______ single doses. |
Repeated, high. |
|
|
In normal functioning kidneys, ____% of Gad will be removed form the body in 12 hrs. All is removed within 24 hours. |
98% |
|
|
In a patient undergoing dialysis, it could take as long as ___hrs for the Gad to be removed. |
54 hours |
|
|
Some sites recommend immediate ___________ after MRI contrast to improve contrast clearance rate in patients with kidney failure. |
Hemodialysis |
|
|
Patient must be fully advised of risks by the ___________ in the case of renal insufficiency and use of contrast. |
Radiologist |
|
|
Recent GFR must be reviewed in patients with a history of... |
- renal disease - history of chronic kidney disease - over 60 years - history of hypertension - history of diabetes - history of severe hepatic disease, liver transplant, pending liver transplant |
|
|
Inflammation of kidneys. |
Glomerulonephritis |
|
|
Abnormal presence of protein in urine can indicate kidney disease. |
Proteinuria |
|
|
Inherited disease of infiltrating cysts in kidneys. |
Polycystic kidney disease. |
|
|
External machine to filter waste from urine. |
Dialysis |
|
|
What can be done about NSF? |
1. Be diligent identifying patients at risk. 2. Assess risk/benefit in high risk patients. 3. Perform unenhanced images. 4. Choose GBCA and dose. 5. What to do after MRI? |
|
|
Measure of how well our kidneys are filtering a waste called creatinine. |
Glomerular filtration rate (GFR) |
|
|
Creatinine is produced by the breakdown of creatinine _________ in muscles. |
Phosphate |
|
|
Normal GFR Range |
90-120mL/min |
|
|
Older people have a ________ GFR. |
Lower |
|
|
Levels below ____mL/min for more than 3 months is considered a sign of ____________. |
60mL/min, chronic kidney disease (CKD). |
|
|
GFR results below ____mL/min are a sign of __________. |
15mL/min, kidney failure. |
|
|
Typically, a radiologist will not administer gadolinium based contrast to a patient with a GFR below ____mL/min. |
30mL/min |
|
|
___________ refers to the use of a contrast agent for a purpose not contained in product labeling. |
Off label. |
|
|
Examples of Off Label Usage |
- pediatrics - pregnancy - increased dose - renal failure |
|
|
Less than __% of administered maternal dose is excreted in breast milk. |
1% |
|
|
Less than __% of contrast in breast milk would be absorbed in the GI tract of the infant. |
1% |
|
|
If the mother desires, she can abstain from breast-feeding for ____hrs and pump and discard milk from both breasts. |
24 hours |
|
|
The technologist should alert the _____________ to any risk factors that were potentially overlooked or not known at the time the exam was ordered with contrast. |
Radiologist |
|
|
Advise the patient of the potential ___________ of using contrast. |
Side-effects |
|
|
There is typically a _________ form listing the required warnings for the patient to read. Confirm that they have ____________ it. |
Consent, read and signed. |
|
|
The technologist will NEVER decide to give contrast without a ____________ order. |
Radiologist's |
|
|
A _______________ is typical in the MRI department with indicated from the radiologist in the protocol (+C, supervised, check) |
Standing order. |
|
|
Many radiologist on-site like to look at pre-Gad images to determine... |
If a dosage of Gad is necessary. |
|
|
Always check the contrast box label and bottle label for... |
Name and expiry date. |
|
|
To draw contrast, you need to use ___________ technique. |
Sterile |
|
|
Record all information relating to the contrast administration, including... |
- patient dosage - lot # - expiry date - who injected - time injected |
|
|
Advise the patient that they may feel a slight ________ sensation up their arm as you inject. |
Cold |
|
|
Signs that the contrast is not injecting. |
- hard to push in - bump on patient's skin - pain |
|
|
Concentration of Magnevist |
0.5M |
|
|
How many mL/kg of Magnevist should be used? |
0.2mL/kg |
|
|
Concentration of Gadovist |
1M |
|
|
How many mL/kg of Gadovist should be used? |
0.1mL/kg |
|
|
Multiply by ______ to go from kg to lb. |
.454 |
|
|
After an injection of contrast, you should follow with a flush of minimum ___mL of saline. |
5mL |
|
|
In brain imaging, the __________ limits the size of molecules that may pass from the blood stream, protecting the brain. |
Blood brain barrier (BBB). |
|
|
If the BBB is disrupted by a ____________, the agent will accumulate in the region and cause enhancement. |
Tumor or lesion. |
|
|
Where should special considerations be made for brain imaging? |
- pituitary - active MS plaques - metastatic lesions |
|
|
In the pituitary, due to quick enhancement, images should be taken __________ after contrast is injected. When imaging the pituitary, a _______ dose. |
Quickly, half dose. |
|
|
__________ MS plaques can be seen post-Gad. |
Active |
|
|
It may be necessary to _________ the dosage to demonstrate small metastatic lesions. |
Increase |
|
|
Optimal enhancement of metastatic lesions will be achieved after a delay of ______ min. |
15 minutes |
|
|
Naturally enhancing structures of the brain (normal for them to be bright after contrast). |
- falx cerebri - tentorium cerebelli - slow moving vessels - pituitary gland/stalk - pineal gland - choroid plexuses - cavernous sinus (venous sinuses) |
|
|
The most common use of contrast in the spine is for the post surgical assessment of the _________. |
L-spine |
|
|
Gad will differentiate ________ tissue caused by surgery from ___________ disc. |
Scar tissue from herniated disc. |
|
|
__________ will initially enhance and within 10 minutes of injection, it will significantly enhance, but ________ do not. |
Scar tissue, discs. |
|
|
After ___ min there will be disc enhancement which can make the differentiation between disc and scar tissue __________. |
30 minutes, difficult. |
|
|
With spine imaging, it is important to scan... |
Immediately after injection. |
|
|
What are we looking for with contrast spine imaging? |
- active MS lesions - spinal mets - bone lesions/infections - syrinxes - discitis |
|
|
The _______, _______ and ________ are highly vascular organs and therefore, contrast will enhance them almost immediately. Rapid imaging is recommended. |
Liver, spleen and kidneys. |
|
|
When imaging a hemangioma, the first pass shows immediate enhancement of _________. |
Malignant lesions. |
|
|
The second pass (time delay of 30, 60, 90 seconds), images show liver/lesion ______ to each other. |
Isointense |
|
|
The third pass (5-20 min), images show enhancement of the _________. |
Benign hemangioma. |
|
|
In breast imaging, Gad is followed by repeated acquisitions, less than ___ min each x ______. |
1 min x 5-7 |
|
|
In the breast, fast enhancing lesions that are spiculated (spiky) in appearance are typically _______. |
Malignant |
|
|
If the contrast washes rapidly in and out of the lesion, it is usually _________. |
Malignant |
|
|
Imaging of the vascular structures in the neck and head. |
Magnetic resonance angiography. |
|
|
In MRA, __________ is very critical. |
Contrast timing. |
|
|
In MRA, you must start your sequence post gad right when the contrast hits the... |
Aortic arch. |
|
|
Any delay in MRA can cause contrast to move into __________ stage. |
Venous |
|
|
MRA is ordered for suspected... |
- aneurysm - artery dissection - arterial malformations - artery blockage/sclerosis - tumors |
