chapter 12 contrast agents

Question 1

to distinguish adjacent tissues on a CT image the tissues must have different

Answer 1

densities (attenuation)

Question 2

CT has 2 main contrast enhancements

Answer 2

intravscular and gastrointestinal

Question 3

when the contrast agent is of higher density it is refereed to as

Answer 3

positive agent

Question 4

when the contrast agent is of a lower density

Answer 4

negative agent

Question 5

contrast has an atomic number of

Answer 5

53

Question 6

2 tissues must differ by at least ___Hounsfield units to be visibly iffernt on a Ct scan

Answer 6

10

Question 7

most intravascular drugs are nearly

Answer 7

isotonic

Question 8

isotonic

Answer 8

have nearly the same number of particles in a solution per unit liquid of blood

Question 9

osmolaity

Answer 9

refers to the number of particles in solution ,per unit liquid, as compared to blood

Question 10

high osmolaity

Answer 10

have seven times the osmolaity of blood

Question 11

low osmolaity

Answer 11

have 2 times the osmolaity of blood

Question 12

the osmolaity of blood plasma is

Answer 12

290 mOsm/kg water

Question 13

viscosity

Answer 13

is a physical property that may be described as the thickness or friction of the fluid

Question 14

half life on contrast

Answer 14

2 hours

Question 15

contrast does not metabolize and is excreted by the body nearly exclusively by the kidneys through

Answer 15

glomerular filtration

Question 16

the most common formula for calculating the dose og contrast for peds

Answer 16

2mL/kg

Question 17

less than ___ of the dose of contrast agent given to the mother is excreted into breast milk

Answer 17

1%

Question 18

contrast reactions can be broadly categorized as

Answer 18

chemotoxic or idoiosyncratic

Question 19

when steroid premedication is used it must be given _____before contrast

Answer 19

6 hours

Question 20

chemotoxic

Answer 20

reactions that stem from the contrast pharamacologic properties

Question 21

the overall kidney function is described as

Answer 21

clearance

Question 22

clearance

Answer 22

the volume of plasma that is cleared of a specific substance in a given time

Question 23

normal adult GFR

Answer 23

120 mL/ min

Question 24

normal ERPF

Answer 24

500 ml/min

Question 25

creatinine

Answer 25

by product of muscle protein metabolism generated by the body at a fairly steady rate and excreted entirely by urine

Question 26

renal failure

Answer 26

the inability of the kidneys to filter waste from the blood

Question 27

renal insufficiency

Answer 27

when renal function is abnormal but capable of sustaining essential bodily function

Question 28

nephropathy

Answer 28

any condition or disease affecting the kidneys

Question 29

anuric ( absence of urine formation)

Answer 29

urine output is less than 50 mL for 24 hours

Question 30

oliguric (diminished urine formation)

Answer 30

urine output is less than 500 ml for 24 hours

Question 31

nonoliguric ( normal output of urine )

Answer 31

500 to 6,000 ml for 24 hours

Question 32

polyuric

Answer 32

urine output in greater than 6,000 mL