Gastrografin
Gastrografin is a high-osmolality, water-soluble iodinated contrast used in gastrointestinal (GI) studies such as barium swallow, meal, follow-through, or enema, especially when bowel perforation or obstruction is suspected.
Why is Gastrografin preferred for GI studies?
Because it is water-soluble and absorbable, making it safe if leakage into the peritoneum occurs (unlike barium). It also has an osmotic effect, drawing water into the bowel to help clear obstructions and enhance mucosal visibility.
Why is Gastrografin not used for cystograms?
It has high osmolality and irritates the bladder mucosa, causing pain, burning, and potential chemical cystitis.
What are the benefits of Gastrografin?
Safe in suspected perforation Clears partial small bowel obstruction Provides strong contrast and mucosal detail
What are the contraindications/risks of Gastrografin?
Aspiration risk (can cause pulmonary edema) Dehydration risk due to osmotic effect Not suitable for bladder or intrathecal use
Urografin
Urografin is a water-soluble iodinated contrast (moderate osmolality) used in urinary tract imaging, such as IVP, retrograde pyelogram, and cystogram (when appropriately diluted).
What are the benefits of Urografin?
Excellent urinary tract opacification Safe when diluted for bladder use Water-soluble and rapidly excreted renally
What are the contraindications/risks of Urografin?
Iodine allergy Renal impairment Dehydration or cardiac disease (osmotic effects)
Omnipaque (Iohexol)
Omnipaque is a non-ionic, low-osmolality iodinated contrast used for CT contrast studies, angiography, myelography, and cystography.
What are the benefits of Omnipaque?
Low osmolality → less patient discomfort and reduced adverse reactions Safe for intrathecal, intravascular, and bladder use Produces high-quality images with minimal irritation
What are the contraindications/risks of Omnipaque?
Iodine hypersensitivity Severe renal impairment (risk of CIN – contrast-induced nephropathy)
Visipaque (Iodixanol)
Visipaque is a non-ionic, iso-osmolar iodinated contrast used in CT, angiography, and urography, especially for patients at risk of contrast-induced nephropathy.
What are the benefits of Visipaque?
Iso-osmolar → excellent patient tolerance Minimizes renal stress Low incidence of allergic or vascular reactions
What are the contraindications/risks of Visipaque?
Iodine allergy Expensive, so often reserved for high-risk patients
What is the purpose of an analgesic in a radiology department?
To relieve pain before, during, or after a procedure to help the patient remain comfortable and still.
What is an example of an analgesic used in radiology?
Paracetamol, ibuprofen, or morphine (for stronger pain relief).
What is the purpose of sedation in a radiology department?
To reduce anxiety, restlessness, or movement during procedures such as MRI, CT, or interventional imaging. It helps patients remain calm and still for image quality and safety.
What is an example of a sedative used in radiology?
Midazolam (a short-acting benzodiazepine).
What is the purpose of a steroid in a radiology department?
To reduce inflammation, allergic reactions, or swelling, especially before or after contrast administration or interventional procedures.
What is an example of a steroid used in radiology?
Prednisone.
What are some minor reactions to iodine-based contrast?
Flushing, Nausea, vomiting, Pruritus (itching), Metallic taste, Light-headedness, Mild urticaria (hives)
How are minor contrast reactions managed?
Close observation and reassurance.
What are some moderate reactions to iodine-based contrast?
Moderate to severe urticaria, Tachycardia or bradycardia, Hypotension, Bronchospasm & wheezing
How are moderate contrast reactions managed?
Prompt treatment with close observation (e.g., antihistamines, IV fluids, oxygen if needed).
