Gastric Emptying

Question 1

Gastric motility

Answer 1

-The ability of the stomach to digest, contract and propel food

Question 2

Gastroparesis risk factors

Answer 2

• IDDM with postprandial symptoms
• Diabetic with poor glucose control
• non-ulcer dyspepsia
• severe reflux esophagitis
• unexplained nausea, vomiting, and pain

Question 3

Rapid empty risk factors

Answer 3

• Gastric surgery
• hyperthyroidism
• duodenal ulcer
• gastrinoma
• rare cases of IDDM
• Thyronine and motilin

Question 4

Rare indications

Answer 4

• Anorexia
• abdominal radiation
• assess response to motility drug
• idiopathic

Question 5

Considerations

Answer 5

• Standing, gravity emptys stomach faster
• gender, menopause causes slow empty
• hyperglycemia, demonstrates a delay @ >144 mg/dL
• metabolic state, increased activity increases empty
• time of day, stomach emptys quicker with no food in it
• smoking, unknown issues causes delay

Question 6

Patient preparation

Answer 6

• NPO 6 hours
• Discontinue medication: Prokinetics 48-72 hrs, opiates
• Fasting blood sugar taken: acceptable <15 mmol/L/ <250 mg/dL
• Allergies

Question 7

Radiopharmaceutical and meal

Answer 7

• Standardized meal
• 1/2 cup of egg whites
• 1 Tbsp of strawberry jam
• 2 slices of toast
• 120 ml of water
• to be eaten in no longer than 10 min
• 99m-Tc sulfur colloid bound to egg whites
• Dose: 37 MBq

Question 8

Protocol

Answer 8

• Upright and supine
• ant and post
• LEAP
• 128 x 128 matrix
• 1 minute images ant 0, 1, 2, 4 hours (3hrs optional)
• May stop if empty at 2 hours

Question 9

Image analysis

Answer 9

• ROI around stomach excluding bowel
• lag time
• % empty and retention
• % empty= Initial counts - current counts/ Initial counts

Question 10

Geometric mean calculation

Answer 10

• corrects for attenuation at each data point
• acquire ant and post views
• geometric mean= square root of counts ant x count post

Question 11

what to document

Answer 11

• Amount of meal eaten
• time to eat meal
• vomiting (repeat)
• Ability to walk or lay flat

Question 12

Study pitfalls

Answer 12

• not consuming whole meal
• prolonged consumption
• lack of attenuation correction
• GI reflux
• poor label
• physical factors
• not NPO

Question 13

1 hour limits

Answer 13

• Delayed: < 10%
• Rapid: > 70%

Question 14

2 hour limits

Answer 14

• normal: >40%
• delayed: <40%
• rapid: >90%

Question 15

4 hour limits

Answer 15

• normal: >90%
• delayed: <90%