Unit 4 Contrast Media + GI, Urinary, Biliary Exams

Question 1

Contrast media visualizes

Answer 1

Soft tissue structures
• GI
• Urinary
• Biliary System
• Myelogram
• Arthrogram
• Vascular Studies (Angiogram)

Question 2

Positive Contrast Medias and how they show up on x-rays

Answer 2

• Radiopaque
• Barium sulfate
• Iodinated contrast media

Appears white on images, Radiopaque

Question 3

Negative Contrast Medias and how they show up on x-rays

Answer 3

• Radiolucent
• Air
• Carbon Dioxide

Appears black on images, Radiolucent

Question 4

BARIUM SULFATE

Answer 4

-Inert organic salt
-Does not chemically react with the body
-Usually no allergy Issues
-Used exclusively for GI tract radiography
-Enteric administration (oral, rectal, NG)
-Packaged in many forms
-Using the proper viscosity is important
-Hygroscopic: Absorbs water, can solidify
-Increase intake of fluids
-May use laxative following exam
-Cannot be absorbed if leaks into peritoneal cavity
-Contraindicated for ruptures of GI system or if surgery likely
-Alternatives: Gastrografin, Hypaque Oral, Nonionic LOCM should be used in cases of suspected esophageal trachea fistula

Question 5

PATIENT PREP FOR GI STUDIES

Answer 5

Diet:
-Low residue or clear liquid diet
-Fasting/NPO orders
-Cathartics: Laxative
-Suppositories: Medication inserted into rectum
-Cleansing Enemas: filling colon with liquid
-Tap water enema: 1000 mL tepid (105 degrees F)
-Bag: 18 inches above the level of the table

Question 6

Upper GI Exams

Answer 6

-Esophagram: ulcers, foreign body, varices, GERD
-Upper GI (stomach): ulcers, gastritis, hiatal hernia
-Patient prep:
-NPO 8-12 hours
-No Smoking, no gum chewing
-Double contrast study: Barium + Air
-The height of the bag of the barium should be 18 inches above the table

Question 7

Small Bowel Exams

Answer 7

-Oral (Small bowel follow through) or Enteroclysis (via catheter)
-Patient Prep: NPO, laxative and/or enema

Question 8

Lower GI: Barium Enema

Answer 8

-Patient Prep: NPO, Laxative and/or cleansing enema
-Contrast administration:
-Patient is placed in SIMS position for enema tip insertion
-Bag filled 1200-1500 mL
-Bag suspended 24-30 inches above the table

Question 9

OTHER BARIUM IMPORTANT TIPS

Answer 9

• Barium sulfate may not be administered intravenously it is insoluble in blood
• Patients should drink plenty of fluids following a barium study.
• The sims position is the body position used when inserting the enema tip.

Question 10

IODINATED CONTRAST

Answer 10

Iodine
-Atomic number: 53
Administration
-IV/IA
-Oral
-Direct injection
Bolus: substantial IV dose
-Characteristics affect clinical performance and whether patient has adverse reaction.
-Iodine Concentration Viscosity
-Toxicity
-Osmolality
Iodine contrast opacity is determined by iodine concentration

Question 11

IODINATED CONTRAST CHARACTERISTICS: Iodine Concentration

Answer 11

• Determines degree to which x-rays will be attenuated
• Higher Concentration results in greater positive contrast but can be more

Question 12

IODINATED CONTRAST CHARACTERISTICS: Viscosity

Answer 12

• Measure of resistance of fluid to flow
• High viscosity is “thick”
• Low viscosity is “thin”
• Can be reduced by warming contrast

Question 13

IODINATED CONTRAST CHARACTERISTICS: Toxicity

Answer 13

• Potential to cause harm
• Least toxic properties: nonionic, low osmolality, injected slowly
-Excessive dose, failure to excrete media, interactions with some medications

Question 14

IODINATED CONTRAST CHARACTERISTICS: Osmolality

Answer 14

• Number of particles in solution per kg of water
• Human blood: 275- 295
• Contrast: 300-1000
• Primarily responsible for adverse effects (Higher osmolality produces adverse effects on pulmonary artery pressure, blood volume, and cardiac output)

• HOCM: High osmolar contrast agent
• LOCM: Low osmolar contrast agent
• Isosmolar: osmolality equals human blood

Question 15

IODINATED CONTRAST

Answer 15

-Precautions: Begin with taking patient history
-Kidney disease Check lab work
-BUN: 6-20 mg/dL
-Creatinine: 0.6-1.5 mg/dL
-GFR: 90-120 mL/min/1.73 m^2
Diabetes Check for metformin
-Medications containing metformin may need to be withheld prior to and after contrast administration
-Heart disease
-Contrast causes vasodilation
-Prior contrast study If so, which agent and dose?
-Max dose for 24-36 hours is 250 mL
-Allergies
-Asthma
-Previous reaction to CM
Note current medications (beta-blockers, blood pressure meds)

Question 16

EXCRETORY UROGRAPHY

Answer 16

-IVP or IVU
-Functional study: images taken at set time periods following the administration of water-soluble nonionic contrast
-Prep: Cleansing of bowel and NPO orders

Question 17

CYSTOGRAM

Answer 17

-Bladder is filled through urinary catheter and examined using fluoroscopy and/or radiographs
-Voiding Cystouerthrogram (VCUG): evaluates bladder and urethra, patient voids on exam

Question 18

RETROGRADE UROGRAPHY

Answer 18

-Retrograde filling of the ureters by placing catheter into renal pelvis
-Performed in OR setting

Question 19

BILIARY SYSTEM: T-TUBE CHOLANGIOGRAM

Answer 19

-After cholecystectomy (removal of gall bladder) T-tube is left in place
-Contrast is injected to check for residual stones or patency before drain removal

Question 20

BILIARY SYSTEMS: ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY (ERCP)

Answer 20

-Performed with Endoscopy
-Scope placed from mouth to duodenum
-Catheter passed into biliary system
-Contrast is used to evaluate for stones/structures

Question 21

MYELOGRAM

Answer 21

• Evaluates structures within the spinal canal
-Herniated disks or impinged nerve roots
• Lumbar puncture performed, injection of contrast
• May include pressure measurements (manometer) and collection of CSF
• Fluoro evaluation with additional images in CT
• Head extended to keep contrast from flowing into cerebral region

Question 22

ARTHROGRAM

Answer 22

-Contrast is injected into joints to evaluate for abnormalities within the joint capsule
-Gas (Carbon dioxide) and/or water soluble contrast

Question 23

IODINATED CONTRAST: IONIZATION

Answer 23

•CNS is sensitive to increased ions in blood; can cause seizures, cardiac disfunction, allergic response

•Ionic: molecules dissociate resulting in more particles
•Nonionic: molecules remain intact
•Ionic-higher osmolality