Radio - Mri Ct

Question 1

Hyperattenuating

Answer 1

White

Question 2

Hypoattenuating

Answer 2

Not attenuating much radiation
Black

Question 3

Window

Answer 3

Range of HU represented on a specific image

Question 4

Hounsfield units

Answer 4

Representation of linear attenuation coefficient for each voxel

Question 5

Level

Answer 5

Central value of the HUs displayed

Question 6

Wide WW

Answer 6

400-1000+ HU
Best for imagin tissue types that vary greatly
Goal is to see all the various tissues in one image
Subtle density discrimination is lost
Lung - both low density parenchyma & high density vascular structures

Question 7

Narrow WW

Answer 7

50-400 HU best for imaging tissue types with similar densities
Provide greater density discrimination & contrast
Brain - white & gray matter

Question 8

Pixel vs voxel

Answer 8

Pixel - picture element and only has 2 dimensions
Voxel - volume picture element and is 3 dimension

Question 9

X & y axis in voxel values

Answer 9

X & y are determined by image matrix size

Question 10

Z axis

Answer 10

Z axis is based on the slice thickness

Question 11

Ct applications - bone

Answer 11

Fractures, elbow dysplasia, ear disease, spinal disease

Question 12

Ct applications - nasal

Answer 12

Tumors, rhinitis

Question 13

Ct applications - lungs

Answer 13

Primary or metastatic tumors, diffuse lung disease, lung lobe torsion

Question 14

Ct applications - abdomen

Answer 14

Masses, portosystemic shunts

Question 15

Advantages of CT

Answer 15

More detailed view of anatomy without superimposition
Faster & less expensive of MRI
Best for bone, lung and abdomen

Question 16

Disadvantages of CT

Answer 16

Radiation exposure
More expensive than radiographs
Poor soft tissue contrast when compared to MRI

Question 17

MRI image is created by

Answer 17

The Anatomic differences and configuration of atoms and molecules within the body. MRI is a large magnet that targets hydrogen protons

Question 18

Hyper intense

Answer 18

White - large amts of intensity

Question 19

Hypointensity

Answer 19

Black - low amounts of intensity

Question 20

T2 sequence

Answer 20

Fluid is bright

Question 21

T1 sequence

Answer 21

Fluid is dark

Question 22

Stir inversion sequence

Answer 22

Suppresses fat signal

Question 23

Flair inversion sequence

Answer 23

Suppresses CSF signal

Question 24

Gradient echo

Answer 24

Fast field echo
Great for detecting hemorrhage

Question 25

Dangers of MRI

Answer 25

Magnet - could be very dangerous and cause projectiles, metal implants etc
The magnet is always on!!

Question 26

Advantages of MRI

Answer 26

Better soft tissue contrast and detail
Noninvasive - no radiation

Question 27

Disadvantages of MRI

Answer 27

Long scan times
General anesthesia
High high cost