Spatial resolution of a noninvasive measurement of the arterial and venous input function using a wrist monitor

The current method for measuring the input function of a PET tomograph is by withdrawing arterial blood from a patient's wrist In this study, the possibility of making a noninvasive measurement of the arterial blood is explored to determine the feasibility of using a planar set of detectors situated around the wrist. The arterial measurement was simulated using a peristaltic pump and an anatomically correct wrist phantom with attenuation. A step function was used to measure the activity flowing through arterial and venous tubing in the phantom. The detector was tested for spatial resolution and counting efficiency. The results showed the detector was able to discriminate the arterial and venous flows from noise when using planar coincidence images.