GI Bleed

Question 1

Purpose of NM GI bleed study

Answer 1

detect and localize acute active or intermittent LOWER GI bleed

Question 2

contraindications

Answer 2

none

Question 3

what modality is best to detect upper GI bleeds?

Answer 3

endoscopy

Question 4

causes of upper GI bleeds

Answer 4

• duodenal ulcer
• varices
• gastric ulcers
• esophagitis
• neoplasm

Question 5

what is considered “upper” GI tract?

Answer 5

esophagus, stomach, duodenum

Question 6

what is considered “lower” GI tract?

Answer 6

jejunum, ileum, colon

Question 7

causes of lower GI bleeds

Answer 7

• diverticular disease
• angiodysplasia
• ulcerative colitis, IBD
• neoplasms
• Meckel’s
• ulcers
• drugs (anticoagulants, steroids, aspirin)
• avm (arteriovenous malformation)

Question 8

what is the ligament of treitz?

Answer 8

band of tissue in abdomen that anchors duodenum and helps move contents along the GI tract

Question 9

what differentiates “upper” and “lower” GI tract?

Answer 9

Whether it is above or below the Ligament of Treitz

Question 10

upper GI bleeds usually = ____ stool

Answer 10

black tarry stool
= melena

Question 11

lower GI bleeds usually = _____ stool

Answer 11

bright red stool
= hematochezia

Question 12

symptoms of GI bleeds

Answer 12

• abdominal discomfort
• weight loss
• weakness, fatigue, dizziness
• blood in stool
• low RBC count/hematocrit

Question 13

treatment for GI bleeds

Answer 13

• laparoscopic cauterization/bowel resection
• medication
• endoscopy
• angiography

Question 14

colonic bleed appearance

Answer 14

periphery of the abdomen

Question 15

small bowel bleed appearance

Answer 15

centre of the abdomen

Question 16

activity found in the same location

Answer 16

think static vascular abnormalities
(I.e. aneurysm, angiodysplasia, hemangioma, etc.)

Question 17

3 criteria for positive GI bleed

Answer 17

1. focal activity where none was initially
2. activity increases over time
3. movement of activity that conforms to intestinal anatomy

Question 18

modality best for upper GI bleeds

Answer 18

endoscopy + gastric aspiration

Question 19

best modality to localize bleeds?

Answer 19

CT angiography

Question 20

dose and RP

Answer 20

740-1110 MBq 99mTc-RBCs

Question 21

normal appearance

Answer 21

heart, liver, spleen, great vessels, kidneys

Question 22

positioning for GI bleed

Answer 22

lower border of liver to pubic symphysis

colby’s: xiphoid to pubic symphysis

Question 23

advantage of in vivo labelling

Answer 23

used for patients that can’t receive blood products

Question 24

disadvantage of modified in vivo

Answer 24

still more prone to iatrogenic interference

Question 25

which has the best labelling efficiency?

Answer 25

in vitro

Question 26

what can affect RBC tagging?

Answer 26

• excess or insufficient stannous ion
• improper labeling technique/timing
• iatrogenic sources

Question 27

what are some iatrogenic sources?

Answer 27

• some medications
• iodinated contrast
• use of recent blood products