PET-MR FAQ

A: PET-MR examinations involve injection of radioactive isotope. The radiation dose is small and will not affect your body function or cause discomfort during the procedure. Besides, the residual radiation inside your body will diminish through natural half-life decay. You will be encouraged to drink plenty of water after the examination to facilitate the excretion of radioactivity. You can get rid of radiation usually within a few hours. You can then resume all daily activities. Avoidance of unnecessary contact with pregnant women and infants on the day of examination is suggested.

A: In order to bring personalized medicine to our patients, we tailor PET acquisition and MR imaging sequences to the clinical question of individual patient through careful combination of whole-body and regional PET-MR imaging. Our goal is to maximize diagnostic accuracy with the most appropriate multi-parametric PET-MR evaluation while enhancing patient acceptance with optimized image acquisition time by simultaneous hybrid scan.

A: Depending on the examination requested by your doctor and the clinical indications, you may be required to have contrast medium injection for more information. Our staff will discuss with you before a contrast enhanced study.

A: Gadolinium-based MRI contrast medium is a safe drug. Reactions are uncommon and usually very mild. Please inform your doctor and our staff if you have previous history of allergy to gadolinium-based MRI contrast medium before examination. Steroid cover on the day before contrast MRI examination may be advised.

• Mild reactions:
  Minor reactions such as headache, dizziness, nausea or vomiting, might occur in about 1% of patients.

• Severe reactions:
  Rarely! Gadolinium-based MRI contrast medium can cause severe reaction, such as convulsion, severe anaphylaxis and death, but is extremely rare. The chance of this fatal occurrence is about 1 in 400,000. For 1-7% of the patients with severely impaired renal function or on dialysis, gadolinium-based contrast media associated with nephrogenic systemic fibrosis and deaths have been reported. Fortunately, with the safety of the newest contrast media, these adverse effects are very rare.

Gadolinium may deposit in various structures of the brain following repeated injection of gadolinium-based MRI contrast media. To date, there is no proof that these gadolinium deposits in the brain have been associated with adverse health effects or pathological consequences.

A: Pregnancy is relatively contraindicated. Please consult our staff if you are pregnant or may be pregnant.

A: Breast-feeding mother may be requested to stop breast-feeding within 48 hours after the examination. Please consult our staff for the precautions of different studies.

A: Most claustrophobic patients can still undergo a PET-MR examination with the assistance of our staff. An intercom system is available between patient and our staff for communication whilst an emergency call bell is also provided during the scan. Some patients may require mild sedation with medication prescribed by doctor. If needed, a family member is allowed to stay with the patient in the scan room throughout the examination after he/she is screened for metal on or in the body.

A: Yes, a requisition form signed by your doctor will provide us with your necessary clinical information; and we will tailor the examination accordingly.

A: The more information that our radiologist has when he reviews your study, the more specific the interpretation will be. Correlations with other studies are often helpful.

A: After the PET-MR examination, our radiologist will interpret your scan and issue an imaging report to your doctor who will then explain the findings and diagnosis to you.