A clinical evaluation of a prototype positron camera for longitudinal emission tomography

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Detector Physics

Background:

• A prototype multiwire proportional-chamber positron camera was developed at Rutherford Laboratory.
• The camera utilizes two opposing 30 x 30 cm2 chambers for positron detection.

Purpose of the Study:

• To evaluate the tomographic performance of the prototype positron camera.
• To assess the effectiveness of 2D-deconvolution for image reconstruction and background removal.
• To compare positron imaging with single-photon studies.

Main Methods:

• Longitudinal tomograms were reconstructed using back-projection and 2D-deconvolution.
• Image noise was filtered during the deconvolution process.
• Phantom studies (68Ga) and patient studies (18F, 18F-FDG, 124I) were performed.

Main Results:

• 2D-deconvolution successfully removed background scatter, improving image quality.
• Spatial resolution was dependent on the filtering cut-off frequency.
• Positron images showed potential advantages over single-photon imaging.

Conclusions:

• The low-cost positron camera is suitable for routine organ imaging.
• Further development is warranted, particularly for use with generator-produced positron emitters.
• Multi-view acquisition is proposed to overcome limitations of limited-angle tomography.