GI System Review

What is the shape of the stomach?

J shaped

What are the 3 major roles of the stomach?

•Reservoir for food

•Breaks down solid food- chyme

•Controls rate of emptying gastric content into the duodenum

What is the anatomy order of the stomach?

mouth, esophagus, stomach, duodenum, jejunum, illium, cecum, large intestine, anus

How does the fundus sit in the stomach?

site proximal and more posterior

Hoe does the antrum sit in the stomach?

sits distal and mroe anterior

What is the small intestine divided into?

divied into the duodenum, jejunum, ileum

What is the anntomy of the large intesttne

cecum, ascending colon, transverse colon, decending colon, sigmoid colon, retum

What are the causes of delayed gastric emptying?

diseases, surgucal procedures, medications

What is gastroparesis?

condition thats effects ability of the stomach to empty it contents, but there is no obstuction

Gastroparesis can either be…?

acute or chronic

What are the clinical symptoms for gastroparesis?

early postprandial satiety, bloating, nausea, vomiting

What are the treatment options for gastroparesis?

various pharmaceuticals, numerous side effects associated with these drugs

What are the indications for gastric emptying?

diebetics with persitent postprandial symptoms, severe reflux, unexplained nuasea and vomiting, asses response to motility drug

What are the clinical symptoms?

nausea, vomiting, abdominal fullness, distention, wieght loss

What are the types of gastric emptying?

solid, liquid, both

What are the food options for the solid gastric emptying study?

eggs (most common), meat, potatoes, oatmeal,pancakes, cornflakes, chicken liver, french toast

What is the patient prep?

NPO after midnight, discontinuation of any medications that may affect motility, refrain from smokin, diebetics should be done first thing in AM 2/3 usual insulin dose

What radiopharmaceuticals do we use for gastric emptying study?

Tc99m Sulfur Colliod, In-111 DTPA

What is the dose for when we use Tc99m SC? solid or liquid?

dose is 0.5-1mci and we put into the eggs (solid); 1mci into water or orange juice (liquid)

What is the dose we give when using In-111 DTPA? solid or liquid?

75-125uci (liquid)

When usung both TC SC and In-111 DTPA, which one is for solid and liquid?

Tc99m SC is for solid and In-111 DTPA is for liquid

How long does the patient have to complete the meal?

10 min

How should the patient be imaged?

upright or supine for at least 90 min

When should we take static images?

every 5-15 min

When should we take dynamic images?

30-60 second/frame

How are the images acquierd?

LAO with single head camera and Anterior and Posterior images with dual head camera

Why is LAO the best view when doing a gastric emptying study?

bc the stomach is not just anterior, fundus is posterior and antrum is more anterior

What the the normal values for solid and liquid?

soild is 90 min and liquid is 10-45 min

What are the advantages of doing a gastric emptying study?

non invasive, sensitive, accurate, quanititaive, simple to perform

What are the disadvantages or advantages for a gastric emptying study?

connot differentiate an anatomical obstruction form functional gastroparesis, and mechanical causes of such as obstruction by tumor have to be excluded by endoscopy

Grastro refulx results from what?

transient sphincter relaxation not associated with swallowing, transient increases in intra-abdominal pressure, free reflux across atonic sphinter.

When dose reflux occur in pedi patients?

7-8 months

What are some common symptoms pedi’s experience?

faliure to thrive, respiratory symptoms, iron deficiency

How long should an adult patient be NPO for a reflux study?

8 hours

How long should an infant be NPO for a reflux study?

one scheduled feeding

What radiopharmacutical do we use for a reflux study?

Tc99m Sulfur colloid

What is the dose for adult patients for a reflux?

200-300uci in 150ml of orange juice and 150ml of hydrochloric acid

What is the dose for infants for a reflux?

200-1000uci in formula

What are the 4 ways for inducce reflux?

oral administration of acidified solution, increased pressure to abdomen, supine position, at least 300ml of volume of liquid

What is the adult procedure for a ruflux study

have patient be supine with camera positioned anteriorly, stomach has to be on bottom of FOV, static images 30sec/frame at following pressure points(0,20,40,60,80,100 mm or Hg)

What is the pedi patient procedure for a reflux study?

patient has to be supine with the camera postioned posteriorly, stomach at bottom of FOV, dynamic images acquierd 5-10 sec/frame for 60 min

What is sensitivity for reflux and aspiration?

reflux: 75-100% and aspiration: 0-25%

is this a pedi or adult?

adult with abdominal cuff

what is this pictuer showing?

a normal gastric image

what is this picture showing?

abnormal-gastroparesis

What are the cuases for an upper GI bleed?

esophageal varies, gastric and duodenal ulcers, gastritis, esophagitis,mallory-weiss tear, neoplasm

What are the causes of a lower GI bleed?

angiodysplasia, diverticular, neoplasms, inflammatory owel diseases, meckels diverticulum

What are the most common sites for GI bleeds?

cecum, hepatic flexure, decending colon, sigmiod colon, rectum

What is the paitne prep for GI bleed?

none

What radiopharmaceutical do we use for Gl Bleed?

Tc99m labeld RBC’s and Tc99m sulfur colloid

What is the dose when we use Tc99m labeled RBC’s?

20-30mci

What is the dose when we use Tc99m SC?

10 mci

How fast can Tc99m labeled RBC’s detect rates?

0.1-0.35ml/min

Why is Tc99m labeled RBC’s the best choice?

for intermittent bleeds because of long intravasular half life (48 hours)

When using Tc99m labeled RBC’s where can it visualize bleeds?

liver and spleen

What is the sensitivity for intermittent bleeding?

>90%

What is the disadvantage when using Tc99m labeled RBS’s?

Free tech is excreated in the kidneys and gastric mucossa and passes into the bladder, small bowel, and colon

When using Tc99m labeled RBC’s imaging can be perfomed up to how many hours post injection?

24 hours post inj

Which tag should be done to prevent free tech?

in vitro or modified invitro

What does In Vivo mean?

inside the body

What is the prodcedure when using the in vivo method?

Inject stannous ion, wait 20-30 min, inject Tc99m-Pertechnetate

For in vivo method the labeling efficency is?

60-90%

What is the procedure when using In vivo/In vitro method?

IV injection of stannous ion, blood sample is collected into a syringe containg Tc99m-pertechnetate and anticoagulant, then re-inejcted

What is the labeling efficiently for In vivo/In vitro?

95%

What is a Pro when doing the In vivo/In vitro method?

Absence of blood manipulation

What does In virto mean?

labeling done outside the body

What is the procedure when doing thr in vitro method?

blood 1-3ml is collected into a syringe containg the anticoagulant, then let it sit for 5 min, then add ACD, then add Tc99m pertechnetate, then wait 20 min and inject

What method has the highest lableing efficiency and superior for image quality?

In vitro method

Which radiopahrmacutical isnt commonly used for GI bleeds?

Tc99m SC

Why is Tc99m SC the best choice for active bleeds?

bc it clears rapdily form intrsvasular space via RE system and maybe cleared before next bleeding episode

What is the disadvantage when using Tc99m SC for GI bleeds?

it clears so rapidly that intermittent bleeding might be missed and the liver and spleen activity

How should the patient be positioned and the camera?

supine, camera is positioned anteriorly over the suspected bleeding site

What normal bisdistribution do we see when we use Tc99m RBC’s?

liver, spleen, abnormal vessles, kidneys, bladder, genitals, stomach

What does normal biodistributuon look like when we use Tc99m SC?

liver, spleen, bone morrow

what is picture showing?

flow phase for GI bleed

what is this pictuer showing?

0-35min dynamic for GI bleed

is this using Tc-RBC’s or Tc-SC?

Tc-RBC’s

is this using Tc-RBC’s or Tc-SC?

Tc-RBC’s

is this using Tc-RBC’s or Tc-SC?

Tc-SC

what is this picture showing and is this using Tc-RBC’s or Tc-SC?

shows and active bleed in the region for the heptatic flexure and this uses Tc-RBC’s

What is the most common benign tumor of the liver?

cavernous hemangioma

Cavernous hemangiomas are often found on CT as what?

an accidental finding

What radiopharmacutical do we use for a liver hemangioma?

Tc99m labeled RBC’s

What is the dose and what is the critical organ?

25mci and the heart

What is the imaging protocol for liver hemangioma?

flow(optional) 1 frame/sec for 60 frames, blood pool(optional) 750-1000k views vary, Delayed imaging 45-180 min post injection (SPECT if indicated)

What is cholecystokinin (CCK)?

a hormone produced by the duodenum

What are the indications for hepatobiliary imaging?

acute or chronic cholecysitits, calculation of GB function, evaluation of bile, jaundice, biliary atresia, biliary leak

What is the peatient prep for a HIDA scan?

pain med that containopium or morphine should be discontinued for at least 4 hours, patient should fast for 4 hours no longer than 24 hours, no recent barrium studies

What radiopharmaceuticals do we use for a HIDA scan?

Tc99m Mebrofenin(choletec) and Tc99m Disofenin(hepatolite)

What is the method of localizeation for radiopahrmaceuticals for a HIDA scan?

active transport

If a patient has a severe hepatocelluar function IDA will be cleared though what?

the kidneys

What is uptake dependent on for a HIDA scan?

chemical structure of IDA compund, hepatic blood flow, viability of hepatocytes, bilirubin level

Whats is the critcal orgna in a HIDA scan?

large intestine

What is the dose for a HIDA scan?

1-5 mci IV

What camera is used for a HIDA scan?

LEAP and LEHR

If a patient has high levels of bilirubin >than 20-30mg/dl, does the dose change?

yes

What is the acquisition protocol for a HIDA scan?

Imaging begins, immediately after injection, liver in upper left hand corner of FOV, optional 60 second flow, dynamic 1-5min/frame for 45-60 min, after forst hours AO’s and right lateral, delay images up to 24 hours post injection

Right lateral position GB lies anteriorly or posteriorly?

anteriorly

What structuers should be seen within one hour?

hepatic parenchyma, biliary ductal system, gallbladder, duodenum

what is this pictuer showing?

normal hepatobiliary