CONTRAST AGENTS IN RADIOGRAPHY

barium sulfate

insoluble, for GI tract imaging

iodinated contrast

water-soluble, for vascular and urinary studies

air/gases

radiolucent, used in double-contrast studies

BaSO4

chemical name of barium sulfate

233.39 g/mol

molecular weight of barium sulfate

4.5 g/cm³

density of barium sulfate

esophagrams, upper Gi series, barium enema

usage of barium sulfate

orally or rectally

barium sulfate can be administered ___________; with orally being the 1st option

90%, 72

_________ of barium sulfate is excreted within __ hours

inert, insoluble in water

barium sulfate considerations

perforations, obstructions

contraindications of barium sulfate

organic iodine

iodinated contrast agents are water-soluble; ____________ compounds

lower osmolarity

non-ionic compounds have ________; lower concentration, lower reaction

higher osmolarity

ionic compounds have ________; higher concentration, higher reaction

IV, intra-arterially, orally

iodinated contrast agents can be administered ________________; with IV being the first option

brachial and radial

sites in administrating iodinated contrast agents intra-arterially

iopamidol (isovue), iohexol (omnipaque)

examples of iodinated contrast agents

constipation, 5%, impaction

adverse reactions to barium sulfate includes: ________ (__%) and _______ (rare)

5-10%

adverse reactions to barium sulfate severity: mild ________

1-3%

adverse reactions to barium sulfate severity: moderate ________

< 0.1%

adverse reactions to barium sulfate severity: severe ________

allergies, asthma, renal impairment

risk factors to contrast agents

contrast-induced nephropathy (CIN)

only contrast agent used in kidneys, especially for nephrons; SPECIAL contrast

creatinine, 0.5

CIN definition: increase in serum ________, greater than or equal _____ mg/dL

2-7%

CIN incidence: ______ in normal renal function

vasoconstriction, tubular toxicity

CIN pathophysiology

hydration, low-osmolar contrast

CIN prevention

patient screening

safety considerations and guidelines: allergy history, renal function

informed consent

safety considerations and guidelines: discuss risks and benefits

emergency preparedness

safety considerations and guidelines: anaphylaxis protocol

barium sulfate

suitable for GI imaging

iodinated agents

suitable for vascular studies

air/gases

helpful in double-contrast techniques

gadolinium

relevant for MRI

weight-based

iodinated contrast media: dosage is generally __________ (mL/kg)

renal function (eGFR)

iodinated contrast media: ______ should be considered for dose adjustments

CT abdomen/pelvis

exam-specific dosage: 1-2 mL/kg

IVU

exam-specific dosage: 0.5-1 mL/kg

angiography

exam-specific dosage: _________ dosage varies

iodine concentration, patient-specific factors

maximum total dose of iodinated contrast agents is limited by __________ and ____________

max of 200 mL

iodinated contrast agent: standard CT contrast

50-100 mL

barium sulfate oral administration: esophagram

200-400 mL

barium sulfate oral administration: upper GI series

additional 200-400 mL

barium sulfate oral administration: small bowel follow through

500-1000 mL

barium sulfate rectal administration: barium enema, depending on colon capacity and exam type

higher concentration

barium sulfate: ____________ for better mucosal coating

lower concentration

barium sulfate: ____________ for faster transit

intravenous (iv)

For CT, angiography, and IVU. Uses rapid bolus or slow infusion techniques.

oral

Barium sulfate and iodinated contrast are used for GI studies. Requires patient instructions.

rectal

Barium sulfate for lower GI studies. Uses balloon catheter insertion.

intrathecal

Iodinated contrast for myelography (less common). Requires strict

sterile technique.

absolute contraindications

life threatening; not bound to happen in the px

relative contraindications

bound to happen after giving contrast media; must be diminished after a few hours

anaphylactic reaction

iodinated contrast media absolute contraindications: prior severe________________

hyperthyroidism

iodinated contrast media absolute contraindications: relative, use caution

renal impairment

iodinated contrast media relative contraindications: _____________ (eGRF < 30)

metformin

iodinated contrast media relative contraindications: _________ use

myeloma

iodinated contrast media relative contraindications: multiple _______

pregnancy, allergy

iodinated contrast media relative contraindications: __________ and known _______ to iodine

bowel perforation

barium sulfate absolute contraindications: known or suspected ________________

bowel obstruction

barium sulfate absolute contraindications: complete ________

anastomotic leak

barium sulfate absolute contraindications: recent GI surgery with ___________

constipation, aspiration, pregnancy

barium sulfate relative contraindications: severe _________, _________ risk, and _________

Nausea, vomiting, flushing, urticaria

mild adverse reactions to iodinated contrast media

Severe urticaria, bronchospasm, vasovagal reaction.

moderate adverse reactions to iodinated contrast media

Anaphylaxis, cardiac arrest, renal failure, CIN.

severe adverse reactions to iodinated contrast media

Constipation, bowel impaction, peritonitis, barium aspiration, allergic reactions.

adverse reactions to barium sulfate

pre-procedure

Assess history, allergies, renal function, hydrate, withhold Metformin, obtain consent

during procedure

Administer contrast agent

post-procedure

Encourage fluids, monitor for reactions, provide instructions

for managing side effects