Brain SPECT Simulation Using Half-Cone-Beam Collimation and Single-Revolution Helical-Path Acquisition

Ter-Antonyan, R.; Jaszczak, R.J.; Bowsher, J.E.; Greer, K.L.; Metzler, S.

doi:10.1109/tns.2007.897826

Cited by 12 publications

(11 citation statements)

References 17 publications

(19 reference statements)

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“…The combined rotational motion of the gantry and the patient axial translation result in a helical trajectory of the collimator focal point around the brain. Similar to helical SPECT proposed for long-object cone-beam imaging (4)(5)(6), pinhole imaging (7), and CT scans (8)(9)(10), helical triple-HCB scans demonstrated markedly improved axial sampling and showed no signs of axial artifacts in simulation and experiments (2,3).…”

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confidence: 73%

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Combination of Converging Collimators for High-Sensitivity Brain SPECT

Ter-Antonyan¹,

Jaszczak²,

Greer³

et al. 2009

J Nucl Med

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The objective of this study, which is related to human brain SPECT, was to increase the sensitivity of a triple-camera SPECT system and reduce statistical noise in reconstructed images using a combination of converging collimators. The reason for combining collimators is to ensure both high sensitivity and sufficient sampling without trading off spatial resolution. Methods: A highsensitivity half-cone-beam (HCB) collimator, designed specifically for brain imaging, was combined with other collimators and compared with conventional parallel-beam and fanbeam circular orbit acquisitions. For comparison, previously studied HCB collimation with a circle-and-helix data acquisition trajectory was also included in this study. Simulations of the Hoffman 3-dimensional brain phantom were performed to calculate the efficiencies of collimators and their combinations and to quantitatively evaluate reconstruction bias, statistical noise, and signalto-noise ratios in the reconstructed images. Experimental brain phantom data were also acquired and compared for different acquisition types. Finally, a patient brain scan was obtained with a combination of HCB and fanbeam collimators and compared with a triple-fanbeam circular orbit acquisition. Results: A combination of 2 HCB collimators and 1 fanbeam collimator, compared with a triple-fanbeam collimator, can increase the photon detection efficiency by 27% and by more than a factor of 2, compared with triple-parallel-hole collimation, with equal spatial resolution measured on the axis of rotation. Quantitative analysis of reconstruction bias and visual analysis of the images showed no signs of sampling artifacts. Reconstructed images in the simulations, experimental brain phantom, and patient brain scans showed improved quality with this collimator combination due to increased sensitivity and reduced noise. Lesion visibility was also improved, as confirmed by signal-to-noise ratios. Alternatively, triple-HCB circle-and-helix acquisition has also shown competitive results, with a slight disadvantage in axial sampling and implementation procedure. Conclusion: Combined HCB and fanbeam collimation is a promising approach for high-sensitivity brain SPECT.

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confidence: 73%

“…To alleviate the axial artifacts, helical HCB data acquisition has been previously investigated with a triple-camera SPECT system (2,3). Helical SPECT scans have been implemented by translating the patient axially as the gantry rotates in a CO.…”

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confidence: 99%

Combination of Converging Collimators for High-Sensitivity Brain SPECT

Ter-Antonyan¹,

Jaszczak²,

Greer³

et al. 2009

J Nucl Med

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“…We used a disk phantom in simulations for revealing evidence of insufficient axial sampling during HCB CO acquisition [7], [8]. The disk phantom consisted of 5 hot and 4 cold disks (thickness = 1.44 cm, radius = 9.0 cm) perpendicular to the AOR.…”

Section: Methods and Simulationmentioning

confidence: 99%

“…Only the slice located on the transaxial focal plane of the HCB collimator, defined as a focal plane perpendicular to the camera axis of rotation (AOR), is sufficiently sampled. To alleviate the axial distortions with HCB collimation, the possibility of helical scans of the human brain similar to helical SPECT proposed for long-object imaging [3], [4], pinhole [5] and X-ray CT scans [6] was recently investigated [7], [8]. During a helical SPECT the patient is translated axially as the gantry revolves in a circular orbit.…”

Section: Introductionmentioning

confidence: 99%

Quantitative evaluation of Half-Cone-Beam data acquisition trajectories in triple- camera brain SPECT

Ter-Antonyan

Jaszczak

Bowsher

et al. 2007

2007 IEEE Nuclear Science Symposium Conference Record

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In this study related to human brain SPECT imaging, simulation of half-cone-beam collimation with different scan paths is performed and compared with simulated fan-beam and parallel-hole circular orbit acquisitions. Acquisition types are quantitatively evaluated based on photon detection efficiency, root-mean-squared error (RMSE) and contrast measurements of reconstructed images. We demonstrate that triple-HCB collimation with a circle-and-helix scan path can offer up to 26% and 128% efficiency increase over fan-beam and parallel-hole collimators (for equal spatial resolutions) correspondingly, and display no visible axial sampling artifacts in reconstructed images. It has a potential for improved data acquisition and image reconstruction, producing higher image quality with smaller reconstruction error (RMSE) and better lesion detectability compared to fan-beam, parallel-hole and half-conebeam circular orbit acquisitions.

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“…Only the slice located on the transaxial focal plane of the HCB collimator, defined as a focal plane perpendicular to the camera's axis of rotation (AOR), is sufficiently sampled. Similar to cone-beam long object tomography [3]- [5], axial translation of the patient is essential with HCB collimation for improved axial sampling [6], [7].…”

Section: Introductionmentioning

confidence: 99%

Half-cone-beam data sufficiency in triple-camera SPECT

Ter-Antonyan

Jaszczak

Bowsher

et al. 2007

2007 IEEE Nuclear Science Symposium Conference Record

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In this study we assess triple-HCB data acquisition for sufficient sampling of the human brain. We find that 2D slices of the brain can be sufficiently sampled by a continuous axially translating triple-HCB source curve prior to their truncation. We hypothesize that if the truncated slices are sufficiently sampled prior to truncation, Tuy's sufficiency condition can be extended to the truncated object. Using simulations we demonstrate that triple-HCB acquisitions with circle-and-line and circle-and-helix scan paths are capable of artifact-free image reconstructions, supporting our hypothesis.

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Brain SPECT Simulation Using Half-Cone-Beam Collimation and Single-Revolution Helical-Path Acquisition

Cited by 12 publications

References 17 publications

Combination of Converging Collimators for High-Sensitivity Brain SPECT

Combination of Converging Collimators for High-Sensitivity Brain SPECT

Quantitative evaluation of Half-Cone-Beam data acquisition trajectories in triple- camera brain SPECT

Half-cone-beam data sufficiency in triple-camera SPECT

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