Gamma Camera/SPECT

FDG (Fluorodeoxyglucose) is a radiolabeled glucose analog used in Positron Emission Tomography-Computed Tomography (PET-CT) scans. Here’s how it works and its role in PET-CT:

1. Glucose Metabolism: FDG mimics glucose and is taken up by cells, particularly those with high metabolic activity, such as cancer cells. Cancer cells have an increased rate of glucose metabolism compared to normal cells, a phenomenon known as the Warburg effect.

2. Radioactive Label: FDG contains a positron-emitting isotope of fluorine (F-18), which emits positrons when it decays. Positrons are positively charged particles that quickly combine with electrons, resulting in the emission of two gamma rays in opposite directions.

3. PET Scan: In PET imaging, FDG is administered to the patient usually via injection. As FDG accumulates in tissues, the emitted positrons collide with electrons in the tissues, resulting in the emission of gamma rays. These gamma rays are detected by the PET scanner.

4. CT Scan: PET is often combined with CT imaging in a single scan session. The CT scan provides anatomical details of the body, aiding in localization and interpretation of PET findings. This combination allows for precise localization of areas of abnormal FDG uptake, helping to differentiate between benign and malignant lesions.

5. Clinical Applications: FDG PET-CT is widely used in oncology for cancer staging, restaging, and monitoring treatment response. It is also used in cardiology, neurology, and infectious disease for various diagnostic purposes.

In summary, FDG is a glucose analog used in PET imaging to detect areas of high metabolic activity, particularly in cancer cells, and its combination with CT imaging provides both functional and anatomical information, enhancing diagnostic accuracy and clinical management.