Positron Emission Tomography/ Computed Tomography (PET-CT Scanning)
Introduction
PET-CT scan (Positron Emission Tomography and Computed Tomography) is a dual modality study combining metabolic and anatomical information. The PET scan demonstrates regional metabolic information, while the CT scan reveals the structure of the organs or lesions within the body. The combination of PET-CT images enable physicians to diagnose and identify cancer accurately
Indications of PET-CT study
Oncology
- Locate primary malignancy
- Staging of the disease before treatment planning
- Monitor therapy response and effectiveness
- Regular follow-up study to monitor the recurrence of cancer
Neurology
Pyrexia of unknown Origin (PUO)
- Patients can undergo this examination to diagnose the fever of unknown origin

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CT image shows rectal wall thickening |
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PET image shows increase FDG uptake in rectum |
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A combined image of PET and CT shows rectal wall thickening with increase metabolic activity, this suggests that the patient suffers from carcinoma of rectum |
Procedures
The most commonly used radiopharmaceutical in PET scan is Fluorodeoxyglucose (FDG). An intravenous catheter will be inserted into the vein of patient for injection of radiopharmaceutical, which will be absorbed by body cells. After IV FDG administration, the patient should take rest for an hour for the uptake of FDG, then scanning is carried out to detect the absorption and distribution of Fluorodeoxyglucose in body cells. As most of the malignant tumours demonstrate FDG avidity, they give stronger signals.
The whole examination process normally takes 2 to 3 hours. However, patients may be required to
undergo a delayed scan 2 hours after the initial scan if necessary.
PET/CT scan is a non-invasive procedure and generally patients do not suffer any discomfort after the examination.
Preparation and requirements include
- Fasting for at least 6 hours prior to the scanning, except small amount of water and medication
- Blood glucose level must be kept at 7.5mmol/l or below, diabetic patients may require special instructions
- No Barium study for 10 days before PET-CT examination
- Avoid exercise before PET-CT examination
- Pregnant women or children under the age of 12 should not accompany the patient for the examination
Post PET-CT examination
- Increase water intake after the examination
- Avoid close contact with pregnant women or children within 24 hours after the examination
Service Hours
| Monday to Friday |
8:30am to 5:30pm |
| Saturday |
9:00am to 1:00pm |
| Closed on Sunday and Public Holidays |
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| For enquiries and appointment, please contact
us at: |
| PET-CT Scanning |
| Address |
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LG1/F, Block C, Hong Kong Baptist Hospital |
| Telephone |
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2337 5679 |
| Fax |
:
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2337 5643 |
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