Description of a prototype emission-transmission computed tomography imaging system

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiology

Background:

• Simultaneous imaging modalities offer advantages in anatomical and functional localization.
• Existing systems may have limitations in spectral discrimination and simultaneous data acquisition.

Purpose of the Study:

• To develop and evaluate a prototype system for combined X-ray computed tomography (CT) and single-photon emission computed tomography (SPECT) imaging.
• To demonstrate the capability of superimposing emission and transmission images for enhanced localization.

Main Methods:

• A novel imaging system utilizing a 23-element high-purity-germanium detector array was developed.
• The system features a collimator angled towards the X-ray tube's focal spot, with synchronous movement of the X-ray fan beam and detector array.
• Simultaneous X-ray transmission CT and SPECT phantom studies were performed using a 3D Hoffman brain phantom.

Main Results:

• The system demonstrated sufficient energy resolution to differentiate X-rays (100-120 kVp) from gamma rays (99mTc).
• The detector array and electronics achieved high count rates (up to 10^6 cps/element).
• Co-registered X-ray CT and SPECT images of a brain phantom were successfully acquired.

Conclusions:

• The developed prototype system can perform simultaneous X-ray CT and SPECT imaging.
• Superimposition of emission and transmission images allows for accurate localization of functional data within anatomical context.
• This technology holds potential for improved diagnostic accuracy in various medical applications.