Imaging small dynamic lesions using positron emission tomography and computed tomography: an ¹⁸F-sodium fluoride...

Area of Science:

• Nuclear Medicine
• Cardiovascular Imaging
• Medical Device Development

Background:

• Fluorine-18 sodium fluoride (18F-NaF) positron emission tomography (PET) is crucial for detecting active microcalcification in bioprosthetic valves.
• Assessing 18F-NaF uptake in small, moving cardiac structures presents significant imaging challenges.
• Bioprosthetic valve deterioration is a critical adverse outcome that requires precise monitoring.

Purpose of the Study:

• To develop and validate a cardiac phantom for optimizing 18F-NaF PET/CT imaging protocols.
• To improve the measurement of 18F-NaF uptake in simulated valvular lesions and subvalvular remnants.
• To enhance the detection and characterization of microcalcifications within moving cardiac structures.

Main Methods:

• A cardiac phantom was engineered with simulated valvular lesions and a subvalvular ring, incorporating 18F-radionuclide.
• High-resolution digital PET/CT imaging was performed using a Siemens Biograph Vision scanner.
• Image quality was assessed using signal-to-noise ratio (SNR), target-to-background ratio (TBR), and subjective analysis, with and without motion correction.

Main Results:

• The phantom achieved high SNR and TBR, comparable to human imaging after reducing scan reconstruction times to 15-30 seconds.
• Motion correction significantly improved SNR and image quality in phantom imaging.
• Phantom imaging results provided a platform for optimizing acquisition and reconstruction parameters for clinical 18F-NaF PET/CT.

Conclusions:

• A cardiac phantom effectively simulates clinical 18F-NaF PET/CT imaging of bioprosthetic valves.
• This phantom facilitates the optimization of imaging techniques for small, mobile cardiac structures.
• The developed phantom aids in advancing the diagnostic capabilities of 18F-NaF PET/CT for valvular heart disease.