Xenon spill distribution and room clearance

Area of Science:

• Medical Imaging Physics
• Nuclear Medicine Technology

Background:

• Xenon-133 (133Xe) gas is used in nuclear medicine imaging.
• Accurate clearance of 133Xe from imaging rooms is crucial for patient safety and image quality.
• Previous clearance time estimations relied on theoretical models that may not reflect real-world conditions.

Purpose of the Study:

• To measure actual xenon gas clearance times under various exhaust conditions.
• To compare measured clearance times with calculated values.
• To investigate the cause of stationary xenon clouds observed in clinical images.

Main Methods:

• Simulated 133Xe gas spills in a controlled room environment.
• Comparison of clearance times with and without a flexible exhaust hose.
• Measurement of clearance times with all room exhaust systems closed.
• Utilizing two gamma cameras to visualize xenon gas transport and exhaust dynamics.

Main Results:

• Clearance times with a flexible exhaust hose were under one minute.
• Conventional room clearance calculations predicted a 22-minute clearance time.
• A stationary xenon cloud artifact was identified as xenon trapped between the collimator and camera face.
• Dedicated exhaust systems with negative pressure are highly effective for xenon removal.

Conclusions:

• Flexible exhaust hoses are essential for rapid and efficient xenon gas clearance.
• Real-world measurements demonstrate significantly faster clearance than theoretical calculations.
• Proper ventilation and exhaust strategies are critical to prevent imaging artifacts and ensure safety.