HIGH YIELD III

Question 1

what is an alternative to Indium for a WBC scan?

Answer 1

Tc-HMPAO

Question 2

name this type of scan based on the description below:

small, neutral, lipophilic complex

crosses WBC cell membrane, draped as hydrophilic complex inside

Answer 2

Tc-HMPAO

Question 3

T/F, Tc-HMPAO does not adversely affect WBC function?

Answer 3

T

Question 4

Tc-HMPAO has a predilection for _____?

this scan, has a higher affinity for?

Answer 4

granulocytes

granulocytes
*tags elutes 5x faster off mononuclear cells
almost pure granulocyte and scan 4, 16-24 hours

Question 5

advantages of Tc-HMPAO vs Indium?

Answer 5

easier prep/readily available
lower radiation dose
rapid imaging times 1-4 hrs
better spatial and contrast resolution
less blood needed

Question 6

Tc-HMPAO has early uptake in what organs?

Answer 6

marrow and spleen

* no RES destruction or uptake, not bone seeking

Question 7

Tc-HMPAO and resolution? describe how this is also in relation to Indium?

Answer 7

delayed images lose resolution but Indium has greater stability in targeted tissue

Question 8

Tc-HMPAO is best for?

Answer 8

acute infection and images resolve with resolution of infection

Question 9

for indium in OM, what is the caution?

Answer 9

indium has most radiation in organs (avoided in children, spleen 17 rads In-111 vs 0.48 HMPAO)

Question 10

what is the gold standard in differentiating diabetic infections vs osteoarthropathy?

Answer 10

WBC scan + bone marrow scans

Question 11

what are the newer radiolabeled techniques?

Answer 11

radio labeled hemostatic peptides

radio labeled liposomes

avidin-mediated agents

radio labeled antibiotics (cipro for TB)

positron emitters, FDG-PET

Question 12

how does a PET scan work in scanning for a tumor?

Answer 12

so, FDG-PET, the FDG gets into metabolically active cells where it becomes trapped-radioisotope identifies cells as tumor cells

Question 13

this type of scan has emerged as the functional imaging modality of choice for diagnosis, staging, therapy, monitoring and assessment of recurrence in cancer?

Answer 13

PET

*FDG is NOT a tumor specific tracer

Question 14

technique of FDG-PET, describe the accumulation?

name the cells that take up the FDG?

what enzyme is responsible for this?

What is FDG bone marrow uptake like?

Answer 14

accumulates in ALL tissues (except brain, heart, kidney and bladder) with a high rate of glycolysis (ACUTE AND CHRONIC INFECTIONS***)

neoplastic cels
activated leukocytes-granulocytes,monocytes,macrophages, lymphocytes

hexokinase

normally low (mild to moderate)

Question 15

advantages of FDG-PET?

what does attenuation allow for?

Answer 15

less labor intensive
earlier imaging time
safer
diagnostic with severe neutropenia
better spatial localization 
works with PET/CT
attenuation 

SUV determination (standard uptake value)

Question 16

this is simple semi-quantitative index for FDG accumulation in tissue (differential uptake/absorption ration)

Answer 16

standard uptake value

Question 17

Charcot complicated OM is better diagnosed by what scan?

Answer 17

MRI, more so than FDG-PET or Tc

Question 18

cross sectional viewing is what kind of scanning?

what can this confirm?

Answer 18

SPECT scanning

confirms OM in the calcaneus

Question 19

what is the nuclear medicine procedure of choice for investigation of diabetic foot infections

Answer 19

labeled WBC imaging, SPECT/CT improves diagnostic accuracy, especially in the mid and hind foot

Question 20

what is not indicated for acute uncomplicated infection MSK?

Answer 20

FDG-PET

Question 21

what is the modality of choice for chronic OM?

Answer 21

FDG-PET

Question 22

indium marrow scanning is indicated for?

what about artifacts with metallic implants?

Answer 22

implant complications

FDG-PET

Question 23

scanning used for complicated diabetic foot infection?

Answer 23

SPECT/CT, possibly FDG-PET/CT coregistered