finals 2

Question 1

head prep

Answer 1

• none (without contrast)
• npo for 4-6 hrs before the examination (w contrast)

Question 2

head position

Answer 2

• supine
• arms along the side of the body
• head immobilized in the head holder

Question 3

head variation

Answer 3

• if there are pathological findings or questions of tumor or metastases
• if there is a possibility of a fracture
• in case of occipital or petrous bone fractures

Question 4

neck patient prep

Answer 4

• none (wo contrast)
• npo for 4-6 hrs before (w contrast)

Question 5

neck posi

Answer 5

• supine
• arms along the side of the body
• head immobilized

Question 6

chest patient prep

Answer 6

• none (wo contrast)
• npo for 4-6 hrs before (w contrast)

Question 7

chest posi

Answer 7

• supine
• arms folded behind the head

Question 8

whole abdomen pt prep

Answer 8

• none (wo contrast)
• npo for 8-12 hrs before examination (w contrast)

Question 9

abdomen posi

Answer 9

• supine
• arms folded behind the head

Question 10

reconstruction process is missed by a moving structure occupying different voxels during the scan

Answer 10

motion artifacts

Question 11

modern scanners commonly include metal correction algorithms that can be used to minimize the appearance of this artifacts

Answer 11

high attenuation objects

Question 12

typical example might occur in the pelvis scan of patient w bilateral hip implants

Answer 12

photon starvation

Question 13

this cause the attenuation coefficient and ct number of a given tissue decrease along the beam path

Answer 13

beam hardening

Question 14

due to detector malfunction

Answer 14

ring artifact

Question 15

reduce the possibility of low contrast detail object and high contrast object

Answer 15

partial volume effect

Question 16

blurring at the boundaries between high contrast details

Answer 16

cone beam effect

Question 17

associated with spiral CT and most apparent on inclined vessels during spiral CTA

Answer 17

“stair step” artifact