3D-OSEM and FP-CIT SPECT quantification

Abstract

Fougè reObjectives Dopamine transporter imaging with singlephoton emission computed tomography (SPECT) is a valuable tool for both clinical routine and research studies. Recently, it was found that the image quality could be improved by introduction of the three-dimensional ordered subset expectation maximization (3D-OSEM) reconstruction algorithm, which provides resolution recovery. The aim of this study was to systematically evaluate the potential benefits of 3D-OSEM in comparison with 2D-OSEM under critical imaging conditions, for example, scans with a high radius of rotation. Materials and methodsMonte Carlo simulation scans of a digital brain phantom with various disease states and different radii of rotation ranging from 13 to 30 cm were reconstructed with both 2D-OSEM and 3D-OSEM algorithms. Specific striatal binding and putamen-tocaudate ratios were determined and compared with true values in the phantom.Results The percentage recovery of true striatal binding was similar between both reconstruction algorithms at the minimum rotational radius; however, at the maximum rotational radius, it decreased from 53 to 43% for 3D-OSEM and from 52 to 26% for 2D-OSEM. 3D-OSEM matched the true putamen-to-caudate ratios more closely than did 2D-OSEM in scans with high SPECT rotation radii.Conclusion 3D-OSEM offers a promising image quality gain. It outperforms 2D-OSEM, particularly in studies with limited resolutions (such as scans acquired with a high radius of rotation) but does not improve the accuracy of the putamen-to-caudate ratios. Whether the benefits of better recovery in studies with higher radii of rotation could potentially increase the diagnostic power of dopamine transporter SPECT in patients with borderline striatal radiotracer binding, however, needs to be further examined.

A new visual rating scale for Ioflupane imaging in Lewy body disease

“…Different methods of semi-quantification exist with no standard approach ( Koch et al, 2005 ; Morton et al, 2005a , Morton et al, 2005b ; Poli et al, 2013 ; Slomka et al, 2001 ; Tossici-Bolt et al, 2006 , Tossici-Bolt et al, 2011 , Tossici-Bolt et al, 2017 ; Varrone et al, 2013 ). Depending on the method used, specific binding ratios may be sensitive to changes in acquisition and processing ( Dickson et al, 2010 ; Koch et al, 2013 , Koch et al, 2014 ; Tossici-Bolt et al, 2011 ; Tossici-Bolt et al, 2017 ). Deriving a suitable local normal range for binding ratios can be problematic ( Dickson et al, 2017 ).…”