Meckel's diverticulum

Question 1

What is Meckel’s

Answer 1

• 2% of population under 2
• occurs in males more frequently
• bleeding will likely occur >40 years
• sac-like out pouching of the small intestine
• 2-3 cm long
• contains heterptopic gastric mucosa which is secreted

Question 2

Meckel’s symptoms

Answer 2

• Bleeding in rectum
• abdominal pain
• ulcers
• inflammed diverticuli

Question 3

Radiopharmaceutical

Answer 3

• 99m-Tc pertechnetate
• Infant dose: 1.85 MBq- 37 MBq
• Adult Dose: 185- 370 MBq
• Target organs: Stomach and thyroid gland

Question 4

Patient prep

Answer 4

• NPO 4-6 hours
• no potassium or sodium percholate
• void bladder
• no barium swallows 3-5 days at least

Question 5

Interventional pre-medications

Answer 5

• Pentegastrine: increases gastric mucosa uptake of pertechnetate
• Glucagon: relaxes smooth muscle of the GI tract, reduces peristalis
• H2 receptor agonists: Rinitadine 2mg/kg 2x a day, cimetadine 20mg/kg 24 hours prior, reduces release of RP from gastric mucosa

Question 6

Acquisition parameters

Answer 6

• supine
• anterior abdomen and xiphoid symphasis
• LEAP or LEHR collimator
• 1min flow 1 sec/fram
• 30-60 minute dynamic
• 30-60 seconds per frame

Question 7

Results

Answer 7

• 99m Tc o4 uptake seen after 10-15 minutes
• activity conforms to intestinal tract
• LRQ focal activity= positive study

Question 8

Causes of false positives

Answer 8

• Urinary tract activity
• ectopic gastric mucosa
• neoplasms
• hemangioma
• hyperemic inflammation

Question 9

Causes of false negatives

Answer 9

• poor technique
• lack of gastric mucosa
• rapid pertechnetate washout
• diverticula <2cm
• poor blood supply to diverticula