A combined static-dynamic single-dose imaging protocol to compare quantitative dynamic SPECT with static conventional SPECT

Sciammarella, Maria; Shrestha, Uttam; Seo, Youngho; Gullberg, Grant T.; Botvinick, Elias H.

doi:10.1007/s12350-017-1016-7

Cited by 10 publications

(7 citation statements)

References 36 publications

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“…The spatiotemporal 4D reconstruction provides information of the temporal changes of the radiotracer at each spatial point without specifics of the cardiac or respiratory motion. The reconstructed images with MC simulation were compared with the data obtained from the conventional spatiotemporal 4D reconstruction that has been implemented in our earlier publications in patient studies ( 12 , 42 ). In these studies, for a TBR = 8 we binned data over each 3-degree view for a total of 120 views per rotation per detector head.…”

Section: Resultsmentioning

confidence: 99%

Monte Carlo Simulation and Reconstruction: Assessment of Myocardial Perfusion Imaging of Tracer Dynamics With Cardiac Motion Due to Deformation and Respiration Using Gamma Camera With Continuous Acquisition

Huh

Shrestha

Gullberg

et al. 2022

Front. Cardiovasc. Med.

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PurposeMyocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) is routinely used for stress testing in nuclear medicine. Recently, our group extended its potential going from 3D visual qualitative image analysis to 4D spatiotemporal reconstruction of dynamically acquired data to capture the time variation of the radiotracer concentration and the estimated myocardial blood flow (MBF) and coronary flow reserve (CFR). However, the quality of reconstructed image is compromised due to cardiac deformation and respiration. The work presented here develops an algorithm that reconstructs the dynamic sequence of separate respiratory and cardiac phases and evaluates the algorithm with data simulated with a Monte Carlo simulation for the continuous image acquisition and processing with a slowly rotating SPECT camera.MethodsA clinically realistic Monte Carlo (MC) simulation is developed using the 4D Extended Cardiac Torso (XCAT) digital phantom with respiratory and cardiac motion to model continuous data acquisition of dynamic cardiac SPECT with slowly rotating gamma cameras by incorporating deformation and displacement of the myocardium due to cardiac and respiratory motion. We extended our previously developed 4D maximum-likelihood expectation-maximization (MLEM) reconstruction algorithm for a data set binned from a continuous list mode (LM) simulation with cardiac and respiratory information. Our spatiotemporal image reconstruction uses splines to explicitly model the temporal change of the tracer for each cardiac and respiratory gate that delineates the myocardial spatial position as the tracer washes in and out. Unlike in a fully list-mode data acquisition and reconstruction the accumulated photons are binned over a specific but very short time interval corresponding to each cardiac and respiratory gate. Reconstruction results are presented showing the dynamics of the tracer in the myocardium as it continuously deforms. These results are then compared with the conventional 4D spatiotemporal reconstruction method that models only the temporal changes of the tracer activity. Mean Stabilized Activity (MSA), signal to noise ratio (SNR) and Bias for the myocardium activities for three different target-to-background ratios (TBRs) are evaluated. Dynamic quantitative indices such as wash-in (K1) and wash-out (k2) rates at each gate were also estimated.ResultsThe MSA and SNR are higher with higher TBRs while biases were improved with higher TBRs to less than 10%. The correlation between exhalation-inhalation sequence with the ground truth during respiratory cycle was excellent. Our reconstruction method showed better resolved myocardial walls during diastole to systole as compared to the ungated 4D image. Estimated values of K1 and k2 were also consistent with the ground truth.ConclusionThe continuous image acquisition for dynamic scan using conventional two-head gamma cameras can provide valuable information for MPI. Our study demonstrated the viability of using a continuous image acquisition method on a widely used clinical two-head SPECT system. Our reconstruction method showed better resolved myocardial walls during diastole to systole as compared to the ungated 4D image. Precise implementation of reconstruction algorithms, better segmentation techniques by generating images of different tissue types and background activity would improve the feasibility of the method in real clinical environment.

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Section: Resultsmentioning

confidence: 99%

Monte Carlo Simulation and Reconstruction: Assessment of Myocardial Perfusion Imaging of Tracer Dynamics With Cardiac Motion Due to Deformation and Respiration Using Gamma Camera With Continuous Acquisition

Huh

Shrestha

Gullberg

et al. 2022

Front. Cardiovasc. Med.

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“…With these various cameras, dynamic cardiac SPECT has been performed with various tracers, including: 201 Tl, 99m Tc‐teboroxime, 99m Tc‐sestamibi, and 99m Tc‐tetrofosmin . Recently, some works have shown that dynamic SPECT has promise for measuring flow and coronary flow reserve (CFR) with rotating large field of view gamma cameras . However, in all of these works, it is recognized that because of the slow camera rotation, dynamic data must be reconstructed directly from the projections themselves, that is, performing 4D reconstruction with appropriate corrections for attenuation, partial volume, and scatter …”

Section: Introductionmentioning

confidence: 99%

“…9,13 Recently, some works have shown that dynamic SPECT has promise for measuring flow and coronary flow reserve (CFR) with rotating large field of view gamma cameras. 8,9,[19][20][21] However, in all of these works, it is recognized that because of the slow camera rotation, dynamic data must be reconstructed directly from the projections themselves, that is, performing 4D reconstruction 1,6,7,9,10,[20][21][22] with appropriate corrections for attenuation, partial volume, and scatter. [23][24][25] Algorithms have advanced, 26 including modeling of cardiac motion in dynamic 5D reconstruction, 27,28 modeling of cardiac and respiratory motion in dynamic 6D reconstruction, 29 and directly fitting compartment models.…”

Section: Introductionmentioning

confidence: 99%

Comparison of sparse domain approaches for 4D SPECT dynamic image reconstruction

Mitra

Abdalah²,

Boutchko

et al. 2018

Medical Physics

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Purpose: Dynamic imaging (DI) provides additional diagnostic information in emission tomography in comparison to conventional static imaging at the cost of being computationally more challenging. Dynamic SPECT (Single Photon Emission Computed Tomography) reconstruction is particularly difficult because of the limitations in the sampling geometry present in most existing scanners. We have developed an algorithm Spline Initialized Factor Analysis of Dynamic Structures (SIFADS) that is a matrix factorization method for reconstructing the dynamics of tracers in tissues and blood directly from the projections in dynamic cardiac SPECT, without first resorting to any 3D reconstruction. Methods: SIFADS is different from “pure” FADS in that it employs a dedicated spline-based pre-initialization. In this paper, we analyze the convergence properties of SIFADS and FADS using multiple metrics. The performances of the two approaches are evaluated for numerically simulated data and for real dynamic SPECT data from canine and human subjects. Results: Most metrics analyzed for reconstruction algorithm convergence show better features of the metric curves versus iterations, In addition, SIAFDS provides better tissue segmentations than that from pure FADS. Measured computational times are also typically better for SIFADS implementations than those with pure FADS. Conclusion: The analysis supports the utility of the pre-initialization of a factorization algorithm for better dynamic SPECT image reconstruction.

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“…While dynamic positron emission tomography imaging can differentiate normal perfusion from balanced ischemia by quantifying coronary flow reverse, 34 most of the current SPECT imaging in clinical practice lack the ability to do so (although the newer generation cameras have shown promising results). 35,36 When myocardial stunning occurs during stress testing, there is impaired myocardial contractility and worsening of mechanical synchrony which can be quantified by phase analysis. In the current single-center cross-sectional study from Mexico, Garcia-Cardenas M et al 37 sought to assess the diagnostic performance and added value of LVMD indices by phase analysis of gated SPECT in discriminating patients with 3-vessel CAD from those without CAD.…”

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confidence: 99%

Left ventricular mechanical dyssnchrony: A potential new marker for 3-vessel CAD

Jalkh

AlJaroudi

2023

Journal of Nuclear Cardiology

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A combined static-dynamic single-dose imaging protocol to compare quantitative dynamic SPECT with static conventional SPECT

Cited by 10 publications

References 36 publications

Monte Carlo Simulation and Reconstruction: Assessment of Myocardial Perfusion Imaging of Tracer Dynamics With Cardiac Motion Due to Deformation and Respiration Using Gamma Camera With Continuous Acquisition

Monte Carlo Simulation and Reconstruction: Assessment of Myocardial Perfusion Imaging of Tracer Dynamics With Cardiac Motion Due to Deformation and Respiration Using Gamma Camera With Continuous Acquisition

Comparison of sparse domain approaches for 4D SPECT dynamic image reconstruction

Left ventricular mechanical dyssnchrony: A potential new marker for 3-vessel CAD

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