Ucsf: Video 5 Part 1 Nuclear Medicine (Gu)

Front 1

What are 3 techniques of looking at the kidney in nuclear medicine

Back 1

tracer clearance
physiologic structure
radionuclide cystography

Front 2

What is tracer is used in tracer clearance

Back 2

MAG3

Front 3

What tracer is used to evaluate the physiologic structure of the kindney in nuclear medicine

Back 3

DMSA

Front 4

What are the 2 types of renal imaging studies in nuc medicine

Back 4

renogram (standard)
cortical imaging

Front 5

What tracer is used for cortical imaging

Back 5

DMSA

Front 6

What tracers are used for a renogram

Back 6

MAG3 or DTPA

Front 7

What to important physiologic quantitative measures that are gained from doing a renogram

Back 7

the GFR and ERPF (effective renal plasma flow)

Front 8

What is the ERPF

Back 8

this is the total perfusion of the kidney that is available for clearance. (80% tubular secreation and 20% GFR)

Front 9

What is excluded in the ERPF

Back 9

capsular secretion (this is not available for clearacn)

Front 10

What is the main reason to to a renal scan

Back 10

for the quantitave measurements (GFR and ERPF)

Front 11

What are 4 common reasons to do a renal scan

Back 11

evaluate:
degree of obstruction
transplant evaluation
suspected ATN
renovascular hypertension

Front 12

How is a renal scan done

Back 12

bolus injection of 10mCi of MAG3
image posteriorly
immediate dynamic phase 2-5 sec per frame for a total of 1 minute
then continous 30-60 per frame second images for about 30 minutes

Front 13

What does it mean if the persfusion of the kidney is good

Back 13

the kidney is usually good bc perfusion mirrors function the one exception is ATN

Front 14

Is renal perfusion relatively perserved in ATN

Back 14

often it is
blood flow is better than might be expected for the degree of renal insufficiency

Front 15

What is split function

Back 15

quantification using ROI

Front 16

How is quantification of the kidneys done on a renal scan

Back 16

ROI drawn of the entire kidney on immediate images.
The relative uptake at about 2-3 minutes post injection is then calculated after background substraction

Front 17

When should the relative uptake be measured

Back 17

at 2-3 minutes before the tracer appears in collecting system

Front 18

How is the ROI drawn when trying to measure clearance

Back 18

the roi is drawn around the periphery of the kidney to avoid counting activity in the collecting system

Front 19

What is a time activity curve

Back 19

this is a curve of clearance and is

renal tracer Vs time

Front 20

Why is the quantative time activity curve of clearance an imperfect science

Back 20

because its difficult not to include the collecting system in the ROI and this causes error.

Front 21

In a standard renogram what tracers are used

Back 21

both MAG 3 and DTAP

Front 22

What is MAG3 used to look at

Back 22

renal perfusion and excretion

Front 23

What is DTAP used for

Back 23

look at GFR

Front 24

What are the two parts to MAG3 portion of the study

Back 24

immediate phase which looks at perfusion for 1 minute (flow or perfusion phase)

then second images for function that last for 30 minutes

Front 25

What is the 1st phase of a renal scan

Back 25

blood flow sequence

Front 26

Can DTAP be used in the renogram flow and function portion

Back 26

yes, but the uptake is not as brisk and excretion is not as quick in the 2nd phase

Front 27

What is being analyzed in the second phase of a renogram

Back 27

the uptake and clearance of tracer from the kidneys.

Front 28

What phase of a renogram is split function quantification done

Back 28

the second phase (function phase or 30 minute phase)

Front 29

How is split function quantification done

Back 29

by making an ROI of kidney, background (subtract out) and bladder (account for lost tracer)

Front 30

When is split function quantificaction done

Back 30

after 2-3 minues (before the tracer gets in collecting system)

Front 31

What tracers can split function be done with

Back 31

MAG3, DTPA or DMSA

Front 32

What is quantified with quantificaiton split function

Back 32

uptake by kidneys (will be different for each)

Front 33

What else is quantified in the 2nd phase of the renogram

Back 33

clearance (draw ROI around periphery of the kidney to avoid the collecting system)

Front 34

What is the name of the curve made from clearance

Back 34

time activity curve of clearance

Front 35

What information is derived from the time activity curve of clearance
3

Back 35

time to peak uptake
T1/2 of clearance from time of peak uptake
fraction of tracer remaining at 20 minutes

Front 36

What is a study that is different from clearance that is used to evaluate the rate of emptying of the collecting system

Back 36

diuretic study

Front 37

What is the difference of a rate of emptying study and clearance

Back 37

rate of emptying demonstrates drainage of the pelvis and calcyes and not renal function

Front 38

How are the ROI different for clearance and emptying studies

Back 38

clearances (ROI around the cortex)

emptying (ROI around the entire kidney)

Front 39

What is an emptying study useful to evaluate

Back 39

hydronephrosis (differentiate obstructed from non-obstructed or how badly obstructed)

Front 40

What is the idea behind using an emptying study to determine if there is obstructed hydronephrosis

Back 40

if the pelvis can be flushed.

Front 41

What preparation is important before a bladder emptying study

Back 41

have the patient void so they have an emptying bladder (will interfere with hydrodyanamics if not)

Front 42

If the T1/2 if less than ten minutes in an emptying study what can be said

Back 42

It is normal

Front 43

If the T1/2 if greater than 20 minutes in an emptying study what can be said

Back 43

it is obstructed (not reliable 30 minutes at cedars)

Front 44

When is lasix given

Back 44

20 minutes after tracer evaluation

Front 45

What is suggested if the kidney is well perfused despite oliguria in a transplant patient

Back 45

ATN

Front 46

What is a suggestion of transplant rejection in a renal scan

Back 46

decreased perfusion but not always

Front 47

In the first phase of a renal scan what are you looking besides flow

Back 47

tortuosity of the aorta and filling time of the aorta, if beyond 5 frames it indicates poor cardiac function.

Front 48

What is seen in transplant ATN with MAG3

Back 48

MAG3- relatively good immediate blood uptake with persiting nephrogam (little washout)

Front 49

What is seen in transplant ATN with DTAP

Back 49

realatively good immediate uptake, kidney fades away without excretion into collecting system.

Front 50

Is RAS easily detected by renal scans

Back 50

no, blood flow is preserved until extremely severe

Front 51

How does an ACE inhibitor work in a captopril scan

Back 51

ACE inhibitors blocks vasoconstriction of the efferent arterioroles and as a result more blood flows out the efferent arterioles and GFR falls.

Front 52

If a person has renal artery stenosis how is blood flow perserved to the glomeruli

Back 52

by angiotensin causing constiction of the efferent arterioles. This causes increased hydrostatic pressure in the glomerulus and maintains renal function.

Front 53

What is the goal of a captopril scan

Back 53

to induce renal dysfunction transiently by using an ACEI

Front 54

What tracer is used for captopril scans

Back 54

MAG3 or DTAP

Front 55

If baseline renal function is compromised is a captopril scan useful

Back 55

no

Front 56

What is a problem with captopril studys of RAS

Back 56

if there is bilateral disease it is difficult to diagnose and a baseline scan may be needed for comparison.

Front 57

What is the appearance of MAG3 in an abnormal captopril scan

Back 57

prolonged nephrogram (uptake is normal but clearance is delayed)

Front 58

What is the appaearnce of DTPA in a captopril study

Back 58

decreased intial uptake and clearance also split function of affected kidny falls)

Front 59

If a pt has RAS what happens to the size of the kidney

Back 59

decreases

Front 60

When doing a captopril study do you have to do a base line study

Back 60

yes, on a different day for a comparison (especially with DTPA)

Front 61

What quantitative test will change when doing comparing baseline to captopril study in a pt with RAS when using DTAP

Back 61

the split function

Front 62

What is DMSA used for?

Back 62

this is for cortical scans

Front 63

How does DMSA work

Back 63

binds to the renal tubules and there is little filtration.

Front 64

When is a cortical scan done

Back 64

in children with pyelonephritis or evaluation of scarring

Front 65

Is cortical scans more sensitive than pyelonephritis

Back 65

yes

Front 66

What is used when doing DMSA scanning

Back 66

spect or pinhole images

Front 67

What are you looking for in a cortical scan

Back 67

areas of the kidney with decreased uptake.

Front 68

What will you see a on a cortical scan of a duplex renal system

Back 68

upper 1/3 with uptake and the lower 1/3 is without uptake.

Front 69

Can you differentiate pyelo from scarring

Back 69

no, both will have decreased uptake.

Front 70

What is another name for a radionuclide cystography

Back 70

RNC

Front 71

What tracer is used in RNC

Back 71

tc-sulfur colloid

Front 72

How is an RNC done

Back 72

pt fills the bladdr to initiate voiding and image continously during filling and voiding of the bladder

Front 73

What is an RNC used to diagnose

Back 73

reflux

Front 74

What is a disadvantage of an RNC to VCUG

Back 74

you cant see the anatomy, or evaluate the urethra

Front 75

When is an RNC done

Back 75

as a follow up to a VCUG