Tomographic imaging of the human thyroid with a positron camera before and after partial thyroidectomy

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Surgical Oncology

Background:

• Positron emission tomography (PET) offers high sensitivity for functional imaging.
• Accurate in vivo assessment of thyroid volume and morphology is crucial for surgical planning and post-operative evaluation.
• Existing imaging modalities may have limitations in spatial resolution and 3D reconstruction for thyroid applications.

Purpose of the Study:

• To evaluate a high-density avalanche chamber positron camera for tomographic imaging of the human thyroid.
• To assess the utility of this imaging technique for pre- and post-surgical assessment in patients undergoing partial thyroidectomy.
• To determine the accuracy of thyroid functional volume estimation using this novel imaging approach.

Main Methods:

• Utilized a high-density avalanche chamber positron camera for tomographic imaging.
• Administered the positron-emitting radionuclide Na-124I orally (0.1-0.3 mCi pre-surgery, 0.03-0.05 mCi post-surgery).
• Acquired images 6-24 hours post-administration in 50 patients, analyzing transaxial sections for volume and surface area.

Main Results:

• Achieved high spatial resolution (2.5 mm FWHM), enabling accurate thyroid functional volume estimation (within ~10%).
• Demonstrated the capability to display thyroid surface using 3D shaded-graphics techniques from transaxial sections.
• Successfully provided a fully three-dimensional in vivo description of the thyroid.

Conclusions:

• The high-density avalanche chamber positron camera provides accurate, high-resolution 3D imaging of the thyroid.
• This technique significantly aids in estimating functional thyroid volume and contributes to effective surgical follow-up.
• The 3D visualization capabilities enhance the understanding of thyroid morphology in vivo.