4 Types of Contrast Media and the Best Solutions
Diagnosing internal health conditions requires medical professionals to highlight areas inside the body. Learn the different types of contrast media and why it’s used commonly in radiology procedures.
For medical professionals such as radiologists and physicians to comprehend what’s happening inside our bodies, they may ask patients to undergo contrast media treatment.
As a proven imaging method, contrast media continues to help patients and medical professionals locate and treat internal medical conditions. And with a reported CAGR of 3.33% expected between 2022 and 2030, the dependency on contrast media solutions will continue to rise globally. Read on to get a better understanding of the core types of contrast media your organisation should be investing in.
What Is Contrast Media?
Contrast media is used in radiology procedures to help diagnose issues by highlighting internal areas and structures of the body. Also referred to as “contrast materials” or “contrast agents”, contrast media are liquid substances which temporarily colour areas of the body to improve the diagnostic effectiveness during imaging procedures.
As the name suggests, “contrast” distinguishes any issues for radiologists to determine medical conditions. Contrast media is a valuable imagining solution applied across the following medical imaging exams:
- X-rays
- Ultrasound
- Computed Tomography (CT)
- Magnetic Resonance (MRI)
- Fluoroscopy
To help physicians diagnose any health conditions, patients receive contrast media substances to highlight features in the image.
Specific contrast media will use certain chemical combinations depending on the procedure. For example, iodine and barium-based compounds support X-ray and CT exams while gadolinium is for MRI and saline is for ultrasound procedures.
How Is Contrast Media Performed?
The patient can consume the contrast media orally (swallowed), by enema (rectal) or via intravenous injection (vein or artery).
X-ray imagining machines function by passing a beam through your body for an X-ray detector to absorb before creating an image. The iodine or barium-based substance essentially block or limit the imaging ability to pass through tissues. This process alters images of the blood vessels, organs, or other internal body tissues.
After consuming the contrast media substance, naturally, the body absorbs it before completely removing it without harm.
However, on rare occasions, contrast media is known to cause some allergic or adverse reactions, so patients must inform doctors of any allergies, medications, and medical conditions alongside recent illnesses or surgeries.
What Are the Different Types of Contrast Media?
As mentioned, specific types of contrast media work for different imaging procedures. Each contrast media procedure performs at the natural location of the suspected condition. For example, oral contrast media exams may focus on the oesophagus or stomach, while rectal will highlight the colon or small intestine.
Here are the four types of contrast media and relative contrast compounds:
1. Oral Contrast Media
Contrast media containing barium-sulphate can be administered orally (swallowed) for X-ray, fluoroscopy, and CT images of the gastrointestinal (GI) tract. These areas include:
- Pharynx
- Oesophagus
- Stomach
- The small intestine
- The large intestine (colon)
In some instances, iodine-based contrast media replaces barium sulphate. Barium sulphate remains the most common form of oral contrast media administration and is available in multiple variations, such as powder, liquid, paste and tablets.
2. Intravenous Contrast Media
Contrast media for intravenous injections across X-ray, fluoroscopic, and CT imaging use an iodine-based substance. For MRI, radiologists will apply gadolinium injections. Gadolinium changes the magnetic properties of water molecules, advancing the speed at which protons realign with the magnetic field. Therefore, the quicker the proton moves, the brighter the image appears.
The areas of the body intravenous contrast media injections aim to highlight, include:
- Internal organs (heart, lungs, liver, kidneys, pancreas, and spleen)
- Gastrointestinal tract (stomach, small intestine, and large intestine)
- Arteries and veins
- Soft tissues (muscle, fat, and skin)
- Brain
- Breast
Intravenous contrast for CT exams is the most used agent. Some cases require speed to maintain the bolus remains tight.
3. Rectal Contrast Media
Rectal contrast media is administered by enema using barium-sulphate. This method of contrast media is applied across X-ray, fluoroscopy, and CT exams to highlight the lower gastrointestinal (GI) tract, distinguishing the colon and rectum areas of the body. Some instances can involve iodine-based contrast media for the same effect. Rectum contrast media solutions are often referred to as barium enemas, as most water-soluble contrast agents used in this method contain barium.
4. Microbubble Contrast Media
Microbubble contrast media involves tiny gas bubbles injected and held together within a supportive shell. It gets the name because the microbubbles are extremely small (smaller than a red blood cell).
As a contrast media solution, microbubbles reflect the ultrasound waves through a process of “echogenicity”. And the higher the volume, the brighter it will appear on the ultrasound scan. The microbubble contrast media is injected into the bloodstream, where ultrasound technology distinguishes differences between the gas bubbles and surrounding tissue. Therefore, the process creates an ultrasound image with distinct contrast.
Various types of medical procedures that involve microbubble contrast media include:
- Blood perfusion in organs
- Abnormal heart conditions
- Liver and kidney masses
- Thrombosis
- Inflammatory activity and bowel diseases
- Chemotherapy treatment response
Microbubble contrast media can be targeted or untargeted. Targeted microbubble contrast media involves the bubbles attaching to a specific area of the body where molecules are bound to the surface of the gas. On the other hand, untargeted is a more common method which helps diagnose diseases by highlighting blood flow with central organs such as the heart and lungs.
Invest in the Best Contrast Media Products
If you’re a radiologist, physician or medical equipment supplier, you may be interested in investing in quality contrast media products. At Wolverson X-Ray, we’ve provided innovative imaging equipment and associated healthcare products for the past 85 years.
Our contrast media products include a range of consumables and injection equipment. Get in touch to find out more.