Prepare a Patient for an Exam

General Instructions 

Little preparation is needed for a CT scan. Patients who do not have fluid restrictions (such as patients with congestive heart failure or in renal failure on dialysis) are asked to drink 64 ounces of water before the exam, especially if the exam is performed with oral or intravenous contrast. If possible, they should start drinking 12 hours before their scheduled appointment time. 

Patients undergoing CT scanning of the chest or heart are asked to avoid caffeine for several hours prior to the exams. 

Patients will be asked to remove jewelry and other metallic objects that might interfere with the scan. We ask patients to leave jewelry at home when possible. 

Pregnancy and Breastfeeding 

CT involves exposure to ionizing radiation (x-rays), which can increase risk of cancer in patients. Our department follows the principle of ALARA, or “as low as reasonably achievable”, making efforts to minimize patient exposure to radiation while maintaining the diagnostic quality of the exam. Depending on the anatomy undergoing CT evaluation, your patient may be asked if there is a possibility that they could be pregnant. Pregnancy testing is available and will be recommended prior to CT examinations of the abdomen, pelvis, and hips when a patient is uncertain about their pregnancy status. Patient counseling regarding the risks of radiation exposure to a fetus will be provided so a patient can make an informed decision about proceeding with an exam during pregnancy.

There is no reason to discontinue breastfeeding to undergo a CT examination, even CT examinations with iodinated IV contrast. The OB Guidelines for Diagnostic Imaging During Pregnancy and Lactation (Committee Opinion, Number 723, October 2017) states: “Traditionally, lactating women who receive intravascular iodinated contrast have been advised to discontinue breastfeeding for 24 hours. However, because of its water solubility, less than 1% of iodinated contrast administered to a lactating woman is excreted into the breast milk, and less than 1% of this amount of contrast will be absorbed through the infant’s gastrointestinal tract. Therefore, breastfeeding can be continued without interruption after the use of iodinated contrast.”

Patient Screening Prior to Administration of Iodinated Contrast 

Prior to the administration of iodinated contrast, patients are screened for the following: 

• Previous reactions to iodinated contrast media 

• Risk factors for renal insufficiency 

Premedication Instructions for Outpatients with Contrast Allergies 

Prednisone 50mg po at 13 hours, 7 hours and 1 hour prior to planned administration of intravenous contrast plus optional diphenhydramine 50mg po at 1 hour prior to planned administration of intravenous contrast 

Or 

Methylprednisolone 32mg po at 12 hours and 2 hours prior to planned administration of contrast plus optional diphenhydramine 50 mg po at 1 hour prior to the planned administration of contrast 

*Note patients with a history of moderate allergic reaction to iodinated contrast will be asked to undergo CT scanning with contrast at one of our hospital facilities to ensure the fastest possible emergency response if they develop a reaction. Iodinated contrast is not administered to outpatients with a history of severe reaction. (Reference ACR Contrast Manual on Contrast Media 2024 - Categories of Acute Reactions, pages 95-96)

Creatinine Testing Prior to Contrast Administration

Routine creatinine testing prior to contrast administration is not necessary in all patients. The test should be obtained within 30 days of contrast administration for patients over 60 years or with history of any of the following: 

• Diabetes 

• Hypertension

• Renal disease or dialysis

• Renal surgery such as transplant, nephrectomy, or ablation 

• Congenital single kidney 

Please note point of care Creatinine testing is available at all our sites and will be utilized when a patient is determined to have risk factors for renal disease. If a patient’s estimated glomerular filtration rate (eGFR) is found to be below 30 ml/min/1.732 or the creatinine has increased by more than 0.5, a radiologist will be consulted to determine if IV contrast administration should proceed. 

Contrast Administration in Patients with Elevated Creatinine 

The decision to proceed with contrast administration in patients with an e GFR < 30 is a matter of clinical judgment, based on the individual circumstances of the patient and following consultation between the radiologist and requesting physician. Strategies to prevent nephropathy in patients with renal impairment include hydration, reduction of contrast dose, and discontinuation of nephrotoxic drugs. 

Contrast Administration in Patients with Renal Failure 

Patients on dialysis may be able to receive IV contrast provided they have been on dialysis chronically (>6 weeks) and are not making urine. The administration of contrast may jeopardize the return of renal function in patients who are receiving dialysis for acute renal failure and may further worsen renal function in patients who still make some urine but receive dialysis intermittently. 

Contrast Administration in Pregnant Patients 

Given that there is no available data to suggest any potential harm to the fetus from exposure to iodinated contrast medium via maternal IV or PO, we do not screen for pregnancy prior to iodinated contrast administration. Iodinated contrast media are categorized by the FDA as a Pregnancy category B medication and is not withheld in pregnant or potentially pregnant patients when it is needed for diagnostic purposes.

You may provide your patients with the following education documents: 

Cardiac Calcium Scoring Only Scan 

Computed Tomography (CT)

Computed Tomography Angiography

Computed Tomography (CT) Cardiac 

They may also visit: https://www.vanderbilthealth.com/service-line/radiology.

VUMC Policy Tech Radiology SOPs 

Pregnancy Testing for Adult Radiology Procedures

Iodinated Contrast Administration for Adut Patients in Radiology Areas

General Instructions

MRI uses strong magnets and radiofrequency waves to create images. The magnet is ALWAYS on. All unnecessary metallic objects, including jewelry and drug delivery patches, MUST be removed prior to the exam. Patients will need to change into a hospital provided apparel prior to their exam because some clothing contains metallic fibers and can be a safety issue for MRI. 

MRI is loud (up to 130dB), and all patients will receive acoustic noise protection for their exam. When possible, two forms of noise protection are utilized, i.e. ear plugs and pads or headphones.

Due to the high-risk nature of the MRI environment, patients cannot have guests with the in the MRI suite except is very special circumstances, such as parents with a young child undergoing MRI. In these circumstances, the guest will be thoroughly screened, will need to wear hearing protection, and will likely be asked to change into a hospital gown. 

Certain exams will have special instructions, such as avoiding food and drink prior to the exam, and exam specific instructions will be shared with the patient. 

Foreign Body and Device Screening Prior to MRI

Patients will need to complete an MRI safety questionnaire prior to their exam asking if they have any foreign bodies (such as needles, ballistic fragments, etc.) or implanted devices (such as aneurysm clips, pacemakers, etc.) in their body. This will be reviewed by the technologist prior to the exam and verification of devices will be requested. 

Please have patients bring to their MRI appointment: 

• Device cards or operative reports (if not available in the VUMC system) 
• Device remote controllers (if applicable) 

Depending on the answer to the MRI safety questionnaire, patients may need screening x-rays prior to an MRI to document foreign bodies and their anatomic location and configuration. 

Certain devices (such as MRI conditional pacemakers) will require additional monitoring and assistance to set the device into MRI mode prior to the exam. For MRI conditional pacemakers, a consultation with cardiology/EP will be needed. 

(See VUMC Policy Tech - Magentic Resonance Imaging (MRI) Safety)

For Patients who are Claustrophobic 

If claustrophobic, the patient can be prescribed an anti-anxiety medication by the referring physician to bring with them to the MRI department for their exam. The patient should discuss timing of taking the prescribed medication with the MRI staff upon arrival. They should bring a driver with them to the appointment and inform the technologist that they are claustrophobic. Examinations can be scheduled with anesthesia, if necessary, but there is very limited availability for this service which can result in scheduling delays.

Creatinine Testing Prior to Gadolinium Administration 

Routine creatinine testing prior to contrast administration is not necessary in all patients.  Serum creatinine with calculation of estimated glomerular filtration rate (eGFR) will be performed in patients with any of the following risk factors: 

• History of renal transplant
• History of acute or chronic renal failure
• On dialysis for less than 6 weeks
• History of kidney disease, including tumor and transplant 

Gadolinium in Patients with Impaired Renal Function

Our radiologists will be consulted prior to administration of contrast in patients with eGFR < 30 ml/min/1.732. All of the gadolinium based contrast agents (GBCA) utilized in the Vanderbilt University Medical Center enterprise are “Group II” agents. The risk of Nephrogenic systemic fibrosis (NSF) (a serious, debilitating, and sometimes fatal scleroderma-like disorder for which the primary risk factor is administration of GBCAs to patients with renal failure) has been shown to be extremely low with Group II GBCAs. Our radiologist will consider this very low risk and make sure that the MRI exam requested is appropriate to address based on the clinical question and that there are not appropriate alternative exams. The patient will receive an information sheet discussing this low risk. For patients on dialysis, same day dialysis after the MRI exam should be performed whenever possible. (See VUMC Policy Tech Radiology SOP - Magnetic Resonance Imaging (MRI) with Gadolinium)

Patient Screening for Allergies

Patients will be asked about any previous reactions to GBCAs. 

Premedication Instructions for Outpatients with Contrast Allergies 

Prednisone 50mg po at 13 hours, 7 hours and 1 hour prior to planned administration of intravenous contrast plus optional diphenhydramine 50mg po at 1 hour prior to planned administration of intravenous contrast 

Or 

Methylprednisolone 32mg po at 12 hours and 2 hours prior to planned administration of contrast plus optional diphenhydramine 50 mg po at 1 hour prior to the planned administration of contrast 

*Note patients with a history of moderate allergic reaction to iodinated contrast will be asked to undergo MRI scanning with contrast at one of our hospital facilities to ensure the fastest possible emergency response if they develop a reaction. GBCAs are not administered to outpatients with a history of severe reaction. Reference ACR Contrast Manual on Contrast Media 2024 – Categories of Acute Reactions, pages 95-96) 

MRI in Pregnant Patients

Patients will be asked about pregnancy status prior to MRI. Pregnancy testing is available and will be recommended to the patient if they are uncertain about their pregnancy status. MRI procedures in pregnant patients are performed only in those cases where the only alternative procedures utilize ionizing radiation and the procedure cannot be reasonably postponed until after the pregnancy. For early first trimester pregnancies (<10 weeks), a radiologist will discuss the benefits/risk of the procedure to the patient and obtain written consent. (See VUMC Policy Tech - Radiology Policy: MRI Procedures - Patient Pregnancy)

Gadolinium in Pregnant Patients 

Intravenous gadolinium is contraindicated in pregnancy (pregnancy FDA category C). It should only be used if absolutely essential and only after discussion of the potential risks and benefits with the patient and referring clinician. 

Gadolinium and Breastfeeding 

“Because of the very small percentage of gadolinium-based contrast medium that is excreted into the breast milk and absorbed by the infant’s gut (estimated to be under 0.0004%), the available data suggest that it is safe for the mother and infant to continue breast-feeding after receiving such an agent.” Stopping or pausing breastfeeding after exposure to GBCAs is not required. (Reference ACR Contrast Manual on Contrast Media 2024 – Breast Feeding Recommendations with Associated Strength of Evidence, page 92) 

You may provide your patients with the following education documents: 

Magnetic Resonance Angiography (MRA)
Magnetic Resonance Cholangiopancreatography (MRCP)
Magnetic Resonance Enterography (MRE)
Magnetic Resonance Imaging (MRI)

They may also visit VanderbiltHealth.com/radiology.

VUMC Policy Tech Radiology SOPs

VUMC Policy Tech - Magentic Resonance Imaging (MRI) Safety 
VUMC Policy Tech Radiology SOP - Magnetic Resonance Imaging (MRI) with Gadolinium
VUMC Policy Tech - Radiology Policy: MRI Procedures - Patient Pregnancy

General Instructions

The patient should arrive 30 minutes before appointment time to check in and complete paperwork. Copies of outside scans, if available, should be brought to the department.

If the patient doesn't follow preparation instructions carefully, the test may not be accurate, and they may need to repeat the scan. It is also likely the scan would need to be rescheduled. 

The patient should be NPO (except water) for 6 hours prior to their appointment time. They should not chew gum or use mints at least 6 hours before the scan. Patients should not do any intense physical activities 24 hours before the scan. This includes physical therapy.

Smoking and nicotine should be avoided immediately prior to the scan.

All jewelry and metal should be removed prior to entering the scan room.

For the procedure, the patient will be escorted to a prep room where they will be injected with FDG for the scan. There are no side effects from the injection of radiolabeled glucose. They will rest quietly in the prep room for approximately 1 hour depending on the type of scan being performed. Subsequently, they will be brought into the scan room to have their scan performed. Most scans take 1.5 to 2 hours. They should plan for their entire visit to be at least 2.5 hours. In some cases, it may take longer.

Patients with Diabetes

Patients with type 1 diabetes need to be euglycemic without recent injection of insulin. The study should be scheduled for late morning, with the patient eating a normal breakfast at around 7am and taking the normal amount of insulin. The patient should then fast for at least 4 hours before the exam.

Patients with type 2 diabetes should fast for at least 4 hours and continue oral hypoglycemic as usual.

For Patients who are Claustrophobic

If claustrophobic, the patient can be prescribed an anti-anxiety medication by the referring physician to take after arriving in the PET department for their exam. They should bring a driver with them to the appointment, and inform the technologist that they are claustrophobic. 

For Patients with Thyroid Cancer

For patients with thyroid cancer, who have rising thyroglobulin and negative I 131 scan, FDG PET can be used to evaluate for papillary and follicular thyroid cancer. These patients should be pretreated with thyrogen prior to their PET scan. This can be scheduled in the nuclear medicine department or through their the referring provider's office.

You may provide your patients with the following education documents: 

PET Scan

They may also visit VanderbiltHealth.com/radiology.

Each patient will receive a call from a nurse at least five days prior to the appointment unless the appointment is made less than five days prior to the scheduled date and time. During this call, the nurse reviews the patient’s medical history and medication list and gives the patient instructions based on the type of procedure that is scheduled. 

General Instructions

Patients who are undergoing outpatient procedures should arrive 1 hour before their scheduled appointment time and check-in at the radiology front desk (room 1145) in the main Vanderbilt University Hospital. 

Patients who are undergoing a procedure that requires overnight observation should arrive 1.5 hours before their scheduled appointment time and should stop by the admitting office prior to checking in at the radiology front desk.

Patients should leave all valuables at home.

Patients who will receive sedation or anesthesia during their procedure must have a friend or family member available to drive them home and care for them for the next 24 hours. 

Most procedures that involve sedation last 1 to 2 hours with a 2 to 4 hour recovery period following the procedure. The patient should expect to be here for at least 4 to 6 hours. 

NPO (Fasting) and Medication Instructions

Only patients who will receive sedation or anesthesia during the procedure need to be NPO.

• No solid food or milk products for 6 hours prior to the procedure.
• No clear liquids for 2 hours prior to the procedure.
• Take all regular medications as scheduled with small sips of water unless otherwise directed.
• For medicine for diabetes: take only half dose of evening insulin; hold morning insulin and oral diabetic medication the day of the procedure. 
• There are many anticoagulants, aspirins and non-steroidal anti-inflammatory medications that may need to be held prior to your procedure. Patients should be asked to keep medical team informed of all medications the patient is taking. If needed, prior to a procedure, our team can review specific medications and plan to manage manage anticoagulation. 

Instructions for Holding Medications Prior to Procedures

Informed Consent

The Department of Radiology recognizes the right of all patients to make informed decisions regarding health care. Informed consent is obtained prior to all interventional or invasive procedures in accordance with the policy approved by Vanderbilt University Medical Center.

You may provide your patients with the following education documents: 

Bland Embolization
BRTO
Chemoembolization
CT-Guided Lung Biopsy
Image-Guided Biopsy
Inpatient Paracentesis
Liver Biopsy
Mapping Arteriogram
Nephrostogram
Outpatient Paracentesis
Outpatient Thoracentesis
Percutaneous Cryoablation
Portal Vein Embolization
TIPS
Vertebroplasty
Y-90: After Your Test
Y-90: General Information

They may also visit VanderbiltHealth.com/radiology.

General Instructions

Most ultrasound examinations do not require any preparation. Patients undergoing an abdominal, gallbladder or renal artery ultrasound should fast for at least 6 hours prior to the exam. Patients undergoing OB Prenatal or Transvaginal Pelvic ultrasound may be asked to drink several glasses of clear fluids prior to the exam in order to have a full bladder. 

You may provide your patients with the following education documents: 

Abdominal Ultrasound
Doppler Duplex Ultrasound
OB Prenatal Ultrasound
Transvaginal Pelvic Ultrasound

They may also visit VanderbiltHealth.com/radiology.

General Instructions

No preparation is needed for a routine X-ray. 

Most GI studies such as esophagrams, UGI's, and barium enemas require that patients fast for 8 hours prior to the exam. Exams such as feeding tube checks to verify placement, nephrostograms, and cystograms do not require patients to be fasting. Enemas and IVP patients are required to do a colon cleansing prep prior to the exam.

You may provide your patients with the following education documents: 

Arthrogram
Barium enema
Cisternogram
Esophagram-barium swallow
Hysterosalpinogram
Intravenous pyelogram (IVP)
Lumbar puncture (spinal tap)
Modified barium swallow
Myelogram
Small bowel follow-through series
Sniff test
Upper GI series
Voiding cystogram
X-Rays

They may also visit VanderbiltHealth.com/radiology.