Preparing for your imaging exam
At St. Joseph's/Candler Imaging Services, our goal is to ensure every imaging exam provides clear and precise results. Some exams require specific preparations, or "prep," which allows our radiologists to capture the most detailed images possible. Following these preparations is essential, as incomplete prep can impact the quality of the images and limit our ability to make a comprehensive diagnosis. If you encounter any challenges in completing the prep requirements, please reach out to us, and we will assist you with alternatives. If your exam isn’t listed, no special preparation is needed. Contact information for both St. Joseph’s and Candler Imaging Services is provided at the end of this guide.
Types of imaging exam preparation
Each imaging exam requires different preparation steps to achieve the best possible outcome. Below are detailed instructions for preparing for various types of exams, including MRI, CT, Ultrasound, X-ray, and other specialized scans.
MRI/MRA Exams
Some MRI exams may require a contrast injection, which helps to visualize certain organs and blood vessels. If you’re scheduled for an MRI, please review the specific requirements below:
- Contrast Requirements: Certain MRI exams require a sodium- and iodine-based contrast. Patients aged 60 or older, or those with diabetes, hypertension, or heart disease (aged 55 or older), will need lab work to check kidney function before their exam. If you’ve had BUN and creatinine results within the last 30 days, we can use these results.
- Claustrophobia and Sedation: For those who may feel anxious, we can provide an oral sedative like Xanax upon arrival. If you opt for sedation, please arrange for someone to drive you home, as you will be unable to drive afterward.
- Metal Items and Implants: You must remove all metal items before the exam, including hairpins, dentures, belts, coins, and credit cards. If you have a pacemaker, cerebral artery clip, aneurysm clip, or cochlear implants, please inform your doctor, as these may affect MRI eligibility. Patients with metal heart valves, rods, pins, or screws will need an evaluation to confirm MRI compatibility.
- Pregnancy Precautions: If you’re pregnant, please ensure that your doctor consults with our radiology team before scheduling your exam.
CT Scans and Special CT Exams
Certain CT exams require specific preparation based on the area of focus, as noted below:
- Standard CT Scans: For CT scans requiring sedation (particularly for pediatric patients), please ensure there is no food or drink for 4 hours before the exam.
- CT Abdomen or Pelvis (With or Without Contrast): No restrictions on food or drink apply. However, if oral contrast is required, you may pick it up from the Imaging Services location the day before the exam with specific instructions on when to drink it. If you are unable to pick it up in advance, please arrive 2 hours before your scheduled time to drink it on-site.
- CT Biopsy, Fine Needle: Please bring any prior CT scans from other facilities and your current medications. We will conduct lab work and review your images on-site.
X-ray Exams with Contrast (X-Ray Dye)
Some X-rays require contrast to highlight certain body structures. If your exam requires contrast, you may need lab work to check kidney function under these conditions:
- X-ray exams with contrast for patients aged 65 or older.
- Patients with diabetes, hypertension, or heart disease aged 55 or older.
Ultrasound Exams
- Abdominal Ultrasound: Do not eat or drink anything for 8 hours before your ultrasound, which will examine structures like the aorta, gallbladder, and liver.
- Pelvic, Obstetrical, or Fetal Age Ultrasound: Drink 36 ounces of liquid before your exam and keep your bladder full, as this aids in producing diagnostic images.
PET, Myocardial Perfusion and Other Specialized Scans
- PET Scan:
- Bring previous CT, MRI, or PET images from other facilities.
- Avoid food or drink for 4 hours before your scan, including gum, candy, and mints.
- Diabetic patients should try to schedule an early appointment or eat and take medications 5 hours before the exam time.
- The facility is kept cool, so bring a sweater or jacket.
- Myocardial Perfusion Scan:
- No food or drink for 8 hours before the appointment.
- Avoid caffeine and certain heart medications for 24 hours prior (consult your cardiologist if needed).
Nuclear Medicine Studies
- Bone Scan: Avoid scheduling within 2 days of a barium study. Arrive for an injection in the morning, then return 3 hours later for the scan.
- Gastric Emptying Study: Schedule this test in the morning. No food or drink after midnight.
- Gallium, HIDA, GI Blood Loss, GI Meckel's, Liver/Spleen, and Thyroid Scans: Preparation includes avoiding food and drink before the scan and ensuring that these tests are not scheduled within 2 days of a barium study.
Cardiolyte/Thallium and Stress Tests
- Exercise (Treadmill) Stress Test: Avoid food and drink after midnight. Consult your cardiologist about heart medication restrictions.
- Persantine/Adenosine Cardiolyte Scan (Non-Exercise): No food, drink, xanthine medications, theophylline, or caffeine for 24 hours before the scan.
