(90)Y bremsstrahlung emission computed tomography using gamma cameras.

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Radiopharmacology

Background:

• Yttrium-90 ((90)Y) is a beta-emitting radioisotope used in targeted radionuclide therapy.
• Bremsstrahlung emission from (90)Y can be utilized for imaging purposes.
• Gamma cameras are standard equipment in nuclear medicine departments.

Purpose of the Study:

• To demonstrate images acquired using (90)Y bremsstrahlung emission computed tomography (BECT).
• To characterize the system performance of gamma cameras for (90)Y BECT.
• To evaluate different energy window settings and reconstruction algorithms for optimal image quality.

Main Methods:

• Phantom imaging with a gamma camera using a medium energy parallel-hole collimator.
• Acquisition of (90)Y BECT images with three distinct energy window widths (75, 120, and 185 keV).
• Image reconstruction using Filtered Back Projection (FBP) and Ordered Subsets Expectation Maximization (OSEM) algorithms; sum window images were also created.

Main Results:

• OSEM reconstruction improved image resolution (Full Width at Half Maximum) by 20% and reduced uncertainty (standard deviation) by 9% compared to FBP.
• (90)Y BECT successfully displayed (90)Y biodistribution and quantified activity.
• The 120 keV window with OSEM yielded the highest resolution and lowest uncertainty; the sum window offered higher sensitivity but slightly lower resolution.

Conclusions:

• (90)Y BECT imaging is a viable tool for patient assessment in nuclear medicine.
• The technique can be implemented without necessitating modifications to existing treatment procedures.
• Optimized energy window selection and reconstruction methods enhance image quality for (90)Y BECT.