The attenuated spline reconstruction technique for single photon emission computed tomography

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Image Reconstruction

Background:

• Single Photon Emission Computed Tomography (SPECT) imaging requires accurate attenuation correction for quantitative analysis.
• Existing reconstruction algorithms like Filtered Backprojection (FBP) and Ordered Subsets Expectation Maximization (OSEM) have limitations in handling attenuation effects.

Purpose of the Study:

• To introduce and mathematically describe the attenuated spline reconstruction technique (aSRT).
• To reconstruct and evaluate simulated and real SPECT/CT data using aSRT.
• To compare aSRT's performance against FBP and OSEM using various image quality metrics.

Main Methods:

• Developed an analytic formula for the inverse attenuated Radon transform using Hilbert transforms and cubic spline interpolation.
• Employed attenuation information from Computed Tomography (CT) scans.
• Reconstructed simulated data with varying noise levels and real phantom/clinical SPECT/CT data.

Main Results:

• aSRT demonstrated efficient and accurate attenuation-corrected reconstructions for both simulated and real data.
• In a clinical myocardial SPECT/CT study, aSRT yielded higher cold contrast compared to FBP and OSEM.
• The technique effectively incorporates attenuation correction within the reconstruction process.

Conclusions:

• aSRT presents a promising alternative to conventional SPECT reconstruction methods, particularly for identifying 'cold' regions indicative of myocardial ischemia.
• The algorithm's ability to integrate attenuation correction offers improved accuracy and image quality.