Gastric Emptying

Question 1

indications

Answer 1

• rate of gastric emptying
• quantitate gastric function and motility
• response to therapy

Question 2

patient prep

Answer 2

• NPO min 4 hrs
• good diabetic control
• d/c non-gastric therapeutic drugs for 48-72 hrs
• d/c prokinetic agents 48hrs
• no smoking morning of and throughout the test

Question 3

examples of pro kinetic agents

Answer 3

• Metoclopramide (Reglan)
• Domperidone (Motilium)
• Cisapride (Propulsid)
• Erythromycin (Motilin Agonist)

Question 4

RP and dose for SOLID gastric emptying

Answer 4

99mTc-SC
18.5-38 MBq

Question 5

RP and dose for LIQUID gastric emptying

Answer 5

99mTc-SC or DTPA
or 111In-DTPA
37 MBq

Question 6

what’s considered standardized meal?

Answer 6

• 2 toasts
• 30 g jam
• 4 oz egg whites
• 100 ml water

Question 7

SC and eggs

Answer 7

binds to albumin in egg whites during cooking

Question 8

imaging protocol

Answer 8

1 min ANT/POST
immediately, 1 hr, 2 hr, 4 hr

Question 9

imaging protocol for liquid emptying

Answer 9

30 min study at 1 min framing rate
imaging to be done immediately after ingestion of 300 ml H2O + RP

Question 10

FOV for gastric emptying

Answer 10

distal esophagus and proximal duodenum

(stomach at top of FOV)

Question 11

camera position and geometric mean calculations

ANT/POST

Answer 11

geometric mean calculation required

Question 12

camera position and geometric mean calculations

LAO

Answer 12

no geometric mean calculation required

Question 13

false positive or false negative

patient consumed a hamburger 1 hr ago

Answer 13

false pos

Question 14

false positive or false negative

last solid meal consumed was 28 hrs ago

Answer 14

false pos

Question 15

false positive or false negative

patient is on TPN

Answer 15

false pos

Question 16

false positive or false negative

chronic cholecystitis

Answer 16

false pos

Question 17

false positive or false negative

acalculous cholecystitis

Answer 17

false neg

Question 18

false positive or false negative

hepatocellular dysfunction

Answer 18

false pos

Question 19

false positive or false negative
“nubbin” sign

Answer 19

false neg

Question 20

false positive or false negative

partial cystic duct obstruction

Answer 20

false pos

Question 21

formula to calculate % empty

Answer 21

% emptying at time (t) = [(corrected ct IMMED - corrected ct at t)/corrected ct IMMED] * 100

Question 22

normal emptying rate at 2H

Answer 22

> 40% emptying

Question 23

normal retention rate at 2H

Answer 23

<60% retention

Question 24

normal retention rate at 4H

Answer 24

<10% retention

Question 25

normal emptying rate at 4H

Answer 25

>90%

Question 26

half time emptying for liquid emptying

Answer 26

<25 min

Question 27

symptoms of Gastroparesis

Answer 27

- post prandial nausea - early satiety - reflux - abdominal pain - vomiting - bloating

Question 28

symptoms of rapid gastric emptying

Answer 28

- post prandial abdominal cramps - diarrhea - palpitations - diaphoresis and weakness

Question 29

treatment for altered gastric emptying rates

Answer 29

- gastrectomy - surgical implant to stimulate vagus nerve - drug therapy (pro kinetics)

Question 30

causes of abnormal delays

Answer 30

- peptic ulceration - surgery - diabetic gastroparesis - scleroderma - amyloidosis - smooth muscle disorders - mechanical obstruction

Question 31

diabetic gastroparesis (delayed GE)

Answer 31

partial paralysis of the stomach due to damage to vagus nerve as it is linked to diabetic neuropathy

Question 32

treatment for delayed GE

Answer 32

- medication - diet management - feeding tube (jejunostomy)

Question 33

what is the process of gastric emptying?

Answer 33

~3 ml of liquid chyme escaping through the pyloric sphincter

Question 34

where are markers placed?

Answer 34

iliac crest (+ uah has it on sternal notch)

Question 35

fundus sits more ____. antrum sits more ____.

Answer 35

fundus - posterior antrum - anterior

Question 36

formula to calculate geometric mean @ Tt

Answer 36

geometric mean @ Tt = sqrt(anterior ct x posterior ct)

Question 37

why are counts seen rising over time in the ANT image?

Answer 37

food moving from the fundus to antrum over time

Question 38

what %s at 0.5H and 1H indicates "dumping"?

Answer 38

>30% at 0.5H >70% at 1H

Question 39

what are normal study results?

Answer 39

when 2H and 4H % emptying values are met OR 2H and 4H % retention values are met

Question 40

2H emptying %

Answer 40

>40% emptied

Question 41

4H emptying %

Answer 41

>90% emptied

Question 42

2H retention %

Answer 42

<60% retained

Question 43

4H retention %

Answer 43

<10% retained

Question 44

why is there a lag phase?

Answer 44

time taken for food to grind into small particles