RT 110 + 111 Unit 1 Ch 12: Upper Gastrointestinal System Procedures & Examinations

What is the main purpose of contrast media in examinations of the gastrointestional unit?

makes soft tissue structures normally hidden or blended in stand out against surrounding tissue

Which contrast media is specifically used for the GI system?

Barium sulfate and/or iodinated (Gastrografin)

Which contrast media is used to visualize blood vessels?

intravascular iodinated contrast media

Why should you obtain a physician's order and patient's written consent before using contrast?

It is considered a medicine that produces physiological responses that must be treated immediately

Why do soft tissue structures with negative contrast appear dark or black on images?

The contrast makes it easier for xray beams to pass through the structures

Which of the following items are considered negative/radiolucent contrast?

Air or gas crystals

Why do soft tissue structures with positive/radiopaque contrast appear white on images?

The contrast absorbs the xrays

Barium sulfate and water-soluable iodinated contrast media have ___ atomic numbers

high

Which type of iodinated contrast is cheaper but more likely to produce allergic reactions?

ionic

Why does ionic iodinated contrast have a higher osmolality (concentration) compared to nonionic?

Ionic particles dissociate or split more frequently, doubling the amount of particles. This increases the thickness and concentration, which can cause a sudden shift in the particles in the bloodstream

Which type of iodinated contrast media is more expensive but less likely to produce allergic reactions?

nonionic

Why do patients tolerate nonionic contrast media better than ionic contrast media?

Its lower osmolality or concentration of particles resembles our blood

T/F: Barium sulfate is a water-soluable substance that can be injected into the bloodstream

False

T/F: Barium sulfate never dissolves in water

True

What information should you obtain before giving a patient contrast media?

A complete clinical history on past experiences with contrast studies, iodine/barium allergies, prior surgeries

GFR, creatinine, & BUN lab results

If a patient is allergy to iodinated contrast media, what can they take before the examination to prevent one?

Corticosteriods (Prednisone) or antihistamines (Diphenhydramine — Benadryl)

What is the main purpose of using double contrast during examinations?

to coat the surface of a tissue structure with positive contrast while pushing the lining of said structure out using negative contrast; helps us see clinical indications

If there's a suspected perforation, which of the following should the technologist consider?

Use water-soluable iodinated contrast instead of barium sulfate

Why should the technologist use water-soluable iodinated contrast instead of barium sulfate if there's a possible perforation?

Barium cannot be absorbed in the body due to its extreme insolubility in water, so it can only escape into the peritoneal cavity.

What happens when barium escapes into the peritoneal cavity?

Peritonitis, blood clots, and hypovolemia/drop in BP

Inflammation of the peritoneum, blood clots within the peritoneal cavity, and a drop in circulating blood plasma volume

T/F: Barium moves quicker through the GI tract than iodine

False

What is fluoroscopy?

Radiographic examination of the function and form of the gastrointestinal tract in motion

What are the common radiographic procedures for the GI system?

esophagraphy/barium swallow & upper GI series

What is the main purpose for an esophagraphy?

To examine the form and function of the pharynx and esophagus

What is the purpose of an upper GI series?

To examine the form and function of the distal esophagus, stomach, and duodenum

How should the patient and room be prepared for an esophagraphy?

1. Patient doesn't have to be NPO

2. Patient needs to be gowned and free from all metallic objects between mouth and waist

3. Have items premixed or laid out in order of operation

4. Take patient history

5. Explain procedure to patient

6. Use a positive contrast (barium)

7. Table should be vertical

How should the patient be prepared for an upper GI series?

1. Have patient be NPO from midnight until time of examination

2. Patient cannot smoke or chew gum

Technical factors for routine esophagraphy projections

40” SID, 110-125 kVp, 14×17” portrait IR, grid, 5-6 collimation field size, center photocell

Patient position for RAO projection esophagography

1. Patient is prone, laying 35-40 degrees on right side

2. Right arm down and left arm is up and flexed holding the drink

3. Tilt chin up

4. Flex left knee for support

5. Place top of IR 2” above shoulders

6. Suspend respiration (patient is drinking, so have them take small drinks)

Where is the CR centered at in an RAO esophagography?

at level of T6, at armpit crease

Patient position for a lateral esophagography

1. Patient is laying fully on right side

2. Hands and arms are near head, with elbows flexed and superimposed (look likes praying)

3. Shoulders and hips are on the same place, putting body in true lateral

4. Midcoronal plane aligns with the middle of the table

5. IR is placed 2” above patient's shoulders

6. Suspend respiration (patient is drinking, so have them take small drinks)

Where is the CR centered for a lateral esophagography?

at level T6, just below the armpit aligned with the midcoronal plane

Patient position for an AP projection of an esophagography

1. Patient is supine with their midsagittal plane aligned with the middle of the table

2. Shoulders and hips are not rotated

3. Right arm holds cup

4. IR is placed 2” above the patient's shoulders

5. Suspend respiration and expose on expiration

Where is the CR centered for an AP projection esophagography?

1” below sternal angle OR 3” below jugular notch

How do you know you have an adequate RAO view of an esophagography?

Esophagus is seen between vertebral column and heart

How do you know you have an adequate lateral view of an esophagography?

Esophagus is seen between thoracic spine and heart

Posterior ribes are directly superimposed