MR contrast agents

Question 1

How does Gadolinium function as a contrast agent?

Answer 1

It shortens the T1 time of tissue

Question 2

The most common positive contrast agent used in clinical MR imaging is

Answer 2

Gadolinium

Question 3

The substances that bind to gadolinium ions are defined as:

Answer 3

Chelates

Question 4

Gadolinium chelates used in MR imaging are

Answer 4

Paramagnetic

Question 5

All of the following are true regarding gadolinium EXCEPT

Answer 5

Gadolinium has six unpaired electrons

Question 6

The FDA approved oral contrast agent for MRI makes bowel appear:

Answer 6

: T1 & T2 hypointense

Question 7

Contraindications for IV gadolinium contrast use are:

A. Pregnant or nursing mothers

B. Sickle cell anemia

C. Insulin dependent diabetes

D. All of the above

Answer 7

None of the above

Question 8

What is the percentage of patients reported to have allergic reactions to gadolinium contrast agents?

Answer 8

Less than 1%

Question 9

IV Gadolinium contrast administration is indicated for:

A. MRCP

B. MRA of the renal arteries

C. Central nervous system

D. A & C only

Answer 9

Central nervous system

Question 10

____________ is used as an anti-peristalsis agent in MR Enterography procedures

Answer 10

Glucagon

Question 11

Metastatic lesions enhance after injecting a gadolinium chelate because of:

A. The breakdown in the blood brain barrier

B. T2 shortening

C. The tangling of arteries and veins in metastatic disease

D. None of the above

Answer 11

The breakdown in the blood brain barrier

Question 12

Gadolinium is an example of a ___________ contrast agent

Answer 12

Paramagnetic

Question 13

In MRI, the function of gadolinium is to

Answer 13

Shorten the T1 and T2 times of tissues

Question 14

The standard dose for the adminstration of IV gadolinium chelates is:

Answer 14

0.1 mmol/kg

Question 15

Gadolinium IV contrast:

Answer 15

Shortens the T1 and T2 times of tissues

Question 16

Following the administration of IV gadolinium contrast, it is recommended to

Answer 16

Follow the injection with a flush of 5 mL saline

Question 17

Following the injection of contrast, which of the following patients are most likely to have a potentially serious reaction?

Answer 17

Those with asthma or allergic respiratory disorders

Question 18

: VoLumen is a contrast agent used for

Answer 18

Bowel enhancement

Question 19

VoLumen would be selected for which MR procedure

Answer 19

MR enterography

Question 20

Calculate the dose of contrast (0.1mmol/kg) that should be administered to a patient weighing 176 lbs with normal kidney function in a routine MR examination.

Answer 20

16mL
Divide 176 lbs by 2.2 (lbs per kg), then multiply the kg (80) by 0.2 ml/kg = 16mL