How Do Other Contrast Media Work?

Contrast media are chemical agents used to improve the contrast in visualizing fluid and tissue structure within the body while performing diagnostic imaging tests. Contrast agents that are not classified into specific classes of contrast media are categorized as other contrast media.

Other contrast media include the following:

• Aminolevulinic acid oral: Aminolevulinic acid is a contrast medium used to visualize glioma, a type of brain tumor that starts in the glial cells of the brain or spinal cord. Aminolevulinic acid gets metabolized in the body into protoporphyrin IX (PpIX), a photoactive compound that accumulates in the tumor cells, the reason for which is not known.
  • Aminolevulinic acid is administered during surgery to clearly visualize the glioma tumor. Seen through an operating microscope with blue light, the glioma tumor tissue with a high concentration of PpIX shows up as red fluorescence while the surrounding tissue with lower concentrations of PpIX appears blue.
• Hexaminolevulinate: Hexaminolevulinate is a compound derived from aminolevulinic acid that reacts similarly and gets converted to protoporphyrin. Hexaminolevulinate is instilled into the bladder to visualize cancerous tissue using blue light cystoscopy, a test performed using a flexible tube with a lens, to look inside the urethra and bladder.
• Sulfur hexafluoride: Sulfur hexafluoride is a contrast medium used for ultrasound imaging of the liver, urinary tract, and the left ventricular chamber of the heart in patients with suboptimal echocardiograms.
  • Sulfur hexachloride is composed of fatty microspheres with a core of gas. Within the bloodstream, the acoustic impedance (resistance) of the microspheres is lower than that of the surrounding nonaqueous tissue. The reflecting ultrasound signals provide a visual image showing a contrast between the blood and surrounding tissues.

Other contrast media may be administered through the following routes:

• Oral solution
• Intravenous injection into a vein
• Intravesical instillation directly into the bladder with a catheter

Other contrast media may be used in the following imaging tests:

• Aminolevulinic acid oral:
  • Glioma imaging in adults, as an adjunct during surgery for the visualization of malignant tissue
• Hexaminolevulinate:
  • Bladder cancer diagnostic test in adults undergoing cystoscopy
• Sulfur hexafluoride:
  • Cardiac imaging to opacify the left ventricular chamber and to improve the delineation of the left ventricular endocardial border
  • Liver ultrasonography for characterization of focal liver lesions
  • Urinary tract ultrasonography to evaluate known or suspected vesicoureteral reflux, a condition in which the urine flows the wrong way

Side effects of other contrast media vary with each contrast agent. A few of the most common side effects may include:

• Aminolevulinic acid oral:
  • Aphasia (language disorder)
  • Hemiparesis (muscle weakness on one side of the body)
  • Hemianopsia (loss of vision of half the visual field)
  • Headache
  • Seizure
  • Hemiplegia (paralysis on one side of the body)
  • Monoparesis (muscle weakness in one limb)
  • Hypoesthesia (reduced skin sensation)
  • Cerebral edema
• Hexaminolevulinate:
  • Dysuria (painful urination)
  • Hematuria (blood in urine)
  • Headache
  • Pain
  • Urinary retention
  • Spasm
• Sulfur hexafluoride:
  • Headache
  • Nausea
  • Dysgeusia (taste disorder)
  • Injection site pain/warmth
  • Chest discomfort/pain
  • Feeling hot

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these products do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of some of the other contrast media include:

• aminolevulinic acid oral
• Cysview
• Gleolan
• hexaminolevulinate
• Lumason
• sulfur hexafluoride