MRI

Question 1

What is MRI?

Answer 1

The use of magnetic fields and radio waves to obtain a mathematically reconstructed image.

Question 2

What does an MRI represent?

Answer 2

The differences among various tissues of the patient in the number of nuclei and in the rate at which these nuclei recover from stimulation by radio waves in the presence of a magnetic field

Question 3

What does MRI technique use?

Answer 3

Makes use of the radio portion of the electromagnetic spectrum

Question 4

What is the energy of a typical photon used?

Answer 4

10 eV

Question 5

What are clinical applications ?

Answer 5

-Must posses in depth knowledge of anatomy including sectional anatomy
-Thorough knowledge of bony landmarks, organs and vessel placement
-Understanding of how technical factors affect signal production
-More sensitive to the molecular nature of tissue and allows excellent contrast resolution

Question 6

What is the most visible and the most often discussed component of the MRI system?

Answer 6

The magnet

Question 7

What does the magnet provide?

Answer 7

The powerful static magnetic field about which the nuclei process

Question 8

What do MRI systems create?

Answer 8

A very strong magnetic field that can be measured in units of tesla

Question 9

What are the field strengths most commonly used clinically?

Answer 9

0.2-3.0

Question 10

What are MR Imaging of the body are performed?

Answer 10

-Organs of the chest and abdomen (Including the heart, liver, biliary tract, kidneys, spleen, intestines, pancreas, and adrenal glands)
-Pelvic Organs (Including the bladder and the reproductive organs -Uterus and ovaries in females and the prostate gland for males)
-Blood vessels
-Lymph Nodes

Question 11

What conditions does it help to diagnose or monitor treatment?

Answer 11

-Tumors of the chest, abdomen, or pelvis
-Diseases of the liver and abnormalities of the bile ducts and pancreas
-Inflammatory bowel diseases
-Heart problems
-Malformation of the blood vessels and inflammation of the vessels
-A fetus in the womb of a pregnant woman
-Breast Cancer

Question 12

What is a traditional MRI unit?

Answer 12

A large cylinder-shaped tube surrounded by a circular magnet

Question 13

Does MRI depend on ionizing radiation?

Answer 13

NO

Question 14

What contrast is used?

Answer 14

Gadolinium-DTPA

Question 15

Why is gadolinium used?

Answer 15

It is metallic and very magnetic

Question 16

What is checked prior to contrast media injection?

Answer 16

BUN & Creatinine levels

Question 17

What are contradictions to MRI?

Answer 17

-Pacemakers
-Ferromagnetic aneurysm clips
-Metallic fragments in eye
-Cochlear implants
-Starr-Edwards pre 6000 model prosthetic heart valve
-Internal drug infusion pumps
-Internal pain pumps (Unless certified as MRI safe)
-Neurostimulators
-Bone growth stimulators
-Ferromagnetic gastrointestinal surgical clips

Question 18

What is a coil?

Answer 18

Single or multiple loops of wire designed to produce a magnetic field from current flowing through the wire or to detect a changing magnetic field by voltage induced in the wire

Question 19

What are the four zones?

Answer 19

-Waiting Area
-Receptionist
-Control Area
-Scanner

Question 20

What are the 3 types of equipment?

Answer 20

-MRI Safe
-MRI Conditional
-MRI Unsafe

Question 21

What is a bore?

Answer 21

The opening to the machine, where the patient goes in

Question 22

What is a quench?

Answer 22

A sudden loss in the magnetic field

Question 23

When is the magnetic off?

Answer 23

The magnet is never off, it is constantly on