What to Eat Before Your CT Scan with Contrast

Your doctor scheduled a CT scan with contrast. Now you are wondering: can I eat beforehand? What should I avoid? Proper preparation helps ensure clear images and a smooth experience. Here is your complete food and drink guide.

Why Preparation Matters

CT contrast dye (an iodine-based solution) is injected into your vein during the scan. It highlights blood vessels, organs, and abnormal tissue. Eating the wrong foods — or eating too close to your scan — can cause nausea or interfere with image quality.

General Fasting Guidelines

Most imaging centers, including AMI, follow these rules for CT scans with IV contrast:

• Stop eating solid food 4 hours before your scan
• Clear liquids are usually okay up to 2 hours before
• Continue taking medications with small sips of water (unless your doctor says otherwise)

These guidelines may vary slightly based on what body part is being scanned. Always follow the specific instructions from your imaging center.

Foods to Eat the Day Before

The day before your scan, eat normally but focus on easy-to-digest foods:

• Lean proteins — Chicken, turkey, fish
• Simple carbohydrates — White bread, rice, pasta
• Cooked vegetables — Carrots, green beans, squash
• Fruit — Bananas, applesauce, melon
• Plenty of water — Staying hydrated helps your kidneys process the contrast

Foods to Avoid Before Your Scan

In the 24 hours before your CT with contrast, avoid:

• Heavy, greasy meals — Fried foods, burgers, pizza
• High-fiber foods — Raw vegetables, beans, whole grains (these digest slowly)
• Dairy-heavy meals — Large amounts of cheese or cream-based sauces
• Alcohol — It dehydrates you and can affect kidney function
• Caffeine in excess — One cup of coffee is usually fine, but avoid energy drinks

The Morning of Your Scan

If your scan is in the morning:

• Skip breakfast or eat only a light meal (toast, crackers) at least 4 hours before
• Drink water freely up to 2 hours before your appointment
• Take your regular medications unless told otherwise

If your scan is in the afternoon:

• Eat a light breakfast (oatmeal, toast, fruit)
• Skip lunch or have only clear liquids
• Continue drinking water

Hydration Is Key

The contrast dye is filtered through your kidneys. Drinking plenty of water before and after your scan helps your body process and eliminate the contrast efficiently. The Radiological Society of North America (RSNA) recommends staying well-hydrated before and after contrast-enhanced exams.

Aim for: - 6 to 8 glasses of water the day before - 2 to 3 glasses the morning of (if allowed) - Extra water after the scan to flush the contrast

Special Considerations

Diabetes If you take metformin, your doctor may ask you to stop it 48 hours before or after the scan. Contrast dye can temporarily affect kidney function, and metformin combined with reduced kidney function can cause a rare but serious condition. Follow your doctor instructions carefully.

Kidney Problems If you have known kidney disease, tell your imaging center. Blood work (creatinine level) may be required before contrast is given. Learn more from the FDA guidance on contrast agents.

Allergies If you have had a reaction to contrast dye before, tell your doctor. Pre-medication with steroids and antihistamines may be needed.

After Your Scan

Once the scan is complete:

• Drink extra water for 24 hours
• Eat normally
• Watch for any unusual symptoms (rash, swelling, difficulty breathing) — these are rare but should be reported immediately

Schedule Your CT Scan

Ready for your CT scan? Call AMI at (727) 398-5999 or schedule online. Our team will provide personalized prep instructions when you book.

Sources: - RSNA — Patient Information - FDA — Contrast Agent Safety