Meckel's

Question 1

purpose of Meckel’s scan

Answer 1

detect and localize meckel’s diverticulum or ectopic/heterotopic gastric mucosa

Question 2

difference between ectopic and heterotopic gastric mucosa

Answer 2

ectopic: organ migrated
heterotopic: tissue at site of origin

Question 3

symptoms of Meckel’s

Answer 3

• painless hematochezia
• presentation of GI bleed in child
• maybe tenderness at umbilicus

Question 4

what are other causes of heterotopic gastric mucosa

Answer 4

• gastrointestinal duplications
• post-operative retained gastric antrum
• Barrett’s esophagus

Question 5

where are meckel’s usually found?

Answer 5

LRQ in distal ileum

Question 6

meckel’s diverticulum is usually caused by…

Answer 6

remnant of fetal omphalomesenteric duct causing outpouching

Question 7

what are the 4 rules of 2?

Answer 7

1. present in 2% of population
2. 2cm outpouching
3. 2 feet from ileocecal value
4. usually diagnosed by 2 yo

Question 8

if obstruction is present, what are the symptoms?

Answer 8

abdominal pain, bloating and nausea

Question 9

treatment for Meckel’s

Answer 9

bowel/diverticulum resection

Question 10

RP and dose

Answer 10

pert at 296-444 MBq (adults)
or 1.85 MBq/kg for peds

Question 11

patient prep

Answer 11

• npo for 2-4 hours
• good hydration
• pharm pre-treatment
• d/c thyroid blocking meds for 48 hrs

Question 12

what does cimetidine do?

Answer 12

inhibits gastric secretions and enhances pert accumulation

Question 13

how does cimetidine do that?

Answer 13

it is antagonist to histamine H2 receptors

Question 14

dose of cimetidine for adults

Answer 14

300 mg, po
given 2 days prior

Question 15

dose of cimetidine for kids

Answer 15

10-20 mg/kg/day for two days prior

Question 16

what is the other pharm that does the same thing as cimetidine?

Answer 16

ranitidine

Question 17

dose of zantac for kids

Answer 17

1 mg/kg up to 50 mg max
slow IV infusion over 20 mins

Question 18

dose of zantac for adults

Answer 18

150-300 mg po
2-3 hours prior

Question 19

what does glucagon do?

Answer 19

decreases peristalsis in bowel = stasis of secreted pert

Question 20

what is glucagon usually coupled with?

Answer 20

pentagastrin

Question 21

dose of glucagon

Answer 21

50 ug/kg to 1 mg/kg IV

Question 22

imaging time when using glucagon

Answer 22

10 mins prior or 10 mins post pert admin

Question 23

what does pentegastrin do?

Answer 23

stimulates gastric secretions = increase rate of TcO4- uptake from blood

Question 24

another name for pentegastrin

Answer 24

peptavalon

Question 25

another name for Ranitidine

Answer 25

zantac

Question 26

dose of pentegastrin

Answer 26

6 ug/kg SQ

Question 27

imaging time with pentegastrin

Answer 27

5-20 mins prior to pert admin

Question 28

fov for meckel's study

Answer 28

abdomen and pelvis (including stomach and bladder)

Question 29

pos for meckel's

Answer 29

- focal area of increased uptake in abdomen (ant LRQ) - uptake increases over time - same timing and intensity as stomach - appears prior to bladder activity

Question 30

normal appearance for meckel's

Answer 30

cardiac blood pool, large vessels that decrease over time, hepatic and splenic pool, stomach (increase over 10-20 mins then decreases over time), early renal activity, collecting system, scrotal/testicle activity

Question 31

false positives

Answer 31

- *urinary tract activity - aneurysms, AVM, hemangioma - bowel inflammation - neoplasms - ulcers, Crohns disease, colitis, peptic ulcer - intussusception - barium enema

Question 32

false negatives

Answer 32

- minimal gastric mucosa, small diverticula - rapid washout - competing meds

Question 33

what other pathologies can be identified with NMT pert scintigraphy?

Answer 33

- gastrointestinal duplications - retained gastric antrum - Barrett's esophagus imaging

Question 34

method of localization

Answer 34

active transport

Question 35

critical organ

Answer 35

large bowel

Question 36

what are pharm pre-treatments used for?

Answer 36

to improve the sensitivity of the study

Question 37

false positives

Answer 37

- inflammatory or obstructive lesion in GI - vascular lesions - normal excretion in GI or urinary tract - ectopic gastric mucosa - recent colonoscopy or laxatives

Question 38

false negs

Answer 38

- small, no gastric mucosa - necrotic mucosa - rapid peristalsis - recent barium or perchlorate