Nuclear Medicine/CNS

Central Nervous System

PET/CT

For Tumor

INDICATION

• For the evaluation or diagnosis of tumors of the central nervous system

PROCEDURE

• Alternate techniques exist. We describe the more common methods.

Dimension

• In 2D mode, septa are usually used to collimate using coincidental detection between 2 adjacent detector rings.
• In 3D mode, all the detector rings are used, which does not necessitate septum separation.

Static Imaging

• The traditional method of acquisition

Dynamic imaging

• A newer, and less used method for detection. Using this approach, there is the potential to measure the metabolic kinetics of a region of interest over time. A time-activity curve can be generated using definable ROIs, which has been used to pre-stage tumors with imaging alone.
• Limitations of this technique includes the (1) highly difficult and technical nature of the technique; (2) somewhat longer time in which the patient needs to keep their head motionless; (3) reliance on arterial input function for metabolic analysis which can be an invasive procedure; (4) lack of compensation for the increased expertise and time needed to acquire and interpret scans; (5) limited outcomes-based research to validate the technique for standard practice.

For Cognitive

INDICATION

• For the evaluation or diagnosis of tumors of the central nervous system

PROCEDURE

Static imaging

• Stuff

INTERPRETATION

• • ^ -- "Society of Nuclear Medicine Procedure Guideline for PDG PET Brain Imaging" (Waxman A.D. Online PDF. Ver 1.0. Feb 9, 2009.

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Acronyms used

ROI - Region of Interest