PET/CT (Positron Emission Tomography / Computed Tomography)
Bangkok PET/CT Center is very proud to present the latest generation of the PET/CT scanning technology to serve patients in Thailand and from other countries in the Asia-Pacific region. The combination PET/CT is a major advance in imaging technology and patient care. The our PET/CT scanner (GEMINI, Philips) is the first to be installed for medical services in Thailand.
What is PET ?
PET (Positron Emission Tomography) is a functional imaging technology using radioisotopes. The medical applications of PET primarily include early detection of cancers, assessment of heart muscle viability in heart diseases and evaluation of functional brain anatomy in dementia, epilepsy and stroke. Across various applications in cancers, the average sensitivity and specificity of 18F-FDG PET were estimated at 84% and 99% respectively. The accuracy ranged from 87% to 90%.
How is PET different from CT or MRI?
By labeling foci of metabolically active cells or tissues in the body, PET provides functional information, which is not available from structure imaging such as CT (Computed Tomography) and MRI (Magnetic Resonance Imaging). However, the spatial resolution of PET is intrinsically limited, that is, it does not generate as detailed a pictorial representation of an organ structure as CT or MRI.
What is PET/CT scanning?
PET/CT scanning is a combination of PET and CT that generates precisely co-registered functional and structural images. This can be achieved by performing both PET and CT studies on the same scanner with no necessity to move the patient. The integrated PET/CT images provide functional information on detailed organ structures in the body.
How does PET work?
PET images are produced by the emission of radiation by an injected or inhaled isotope in tissue. By using different substances of biology interest labelled with positron emitting radionuclide (PET radiopharmaceutical). The PET systems have the advantage of using physiologically important isotopes, such as 11-Carbon, 13-Nitrogen, 15-Oxygen, and 18-Fluorine (18F). A cyclotron is needed in generating these positron-emitting isotopes that have short half-lives.
18F-FDG (2-(18F)fluoro-2-deoxy-D-glucose) PET is able to measure different rates of glucose metabolism in various tissues or organs that use glucose to obtain energy. The radiation during PET/CT scanning is equal to the amount of radiation exposure during two chest x-rays.
Applications of 18F-FDG PET in cancer scanning ?
- Early detection of cancers of various organs, such as lung cancer, head and neck cancer, colorectal cancer, melanoma, lymphoma, breast cancer, ovarian cancer, and pancreatic cancer.
- Staging of cancers.
- Monitoring the response to therapy.
- Assessment of the effectiveness of treatments.
- Detection of the recurrence.
18F-FDG PET, by means of providing information on the metabolic activity of tissues, is able to detect small foci of early cancer, especially in case it has spread to other organs of the body (metastases). In contrast, with CT or MRI, the cancer must reach a significant size enough to distort the surrounding structures before the effect will show up on the scans.
PET/CT in Heart System
PET/CT can be used for assessment of heart muscle viability in heart diseases and myocardial perfusion. The sensitivity is more than 90%.
PET/CT in Brain System
- Brain tumor : diagnostic and follow up after treatment
- Diagnostic and high accuracy of localization of seizure in the brain results in very effective surgery treatment
- Dementia : diagnostic pathology and the cause of dementia for an efficient and accurate treatment (especially in elder persons)
What are the procedures involved in PET/CT scanning?
- Fasting for a period of at least 6 hours prior to scanning
- Measuring fasting blood glucose
- Injecting the radioisotope agent via the patient’s cubital vein
- Resting for a short period of time
- Positioning on the scanning bed and keeping still during scanning
- Scanning times vary with the procedures, generally about 20-60 minutes
- After the scanning, the radiologist will interpret the images and report to the referring physician who will then discuss the finding with the patient