Quality evaluation of image recording strategies for limited angle tomography

Stopp, F.; Winne, C.; Jank, Emanuel; Keeve, Erwin

doi:10.1016/s1007-0214(10)70004-3

Cited by 3 publications

(5 citation statements)

References 8 publications

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“…Future work could include detailed comparison between different analytical FOMs (e.g., Refs. 20, 31–35) in terms of their correlation with zmod and/or other empirical task-based sampling completeness metrics.…”

Section: Discussionmentioning

confidence: 99%

“…If the fraction is 1.0, then Tuy’s condition is satisfied at that voxel, and fractions <1.0 correspond to an increased potential for cone-beam artifact at that location. Other authors 33 , 34 computed a FOM that can accommodate a finite number of source locations or as a continuous trajectory: for each plane passing through the voxel, the sine of the angle of the nearest source location is calculated, and an angle of zero means that the plane contains an x-ray source location; averaging these values over all planes 33 (or alternatively, taking the maximum value 34 ) provides a FOM that correlates with sampling completeness at that location. Alternatively, the information for each plane need not be combined, and the angular values corresponding to all planes intersecting the voxel are considered in full 11 , 35 .…”

Section: Introductionmentioning

confidence: 99%

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Cone-beam CT sampling incompleteness: analytical and empirical studies of emerging systems and source–detector orbits

Tersol

Clackdoyle

et al. 2023

J. Med. Imag.

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.PurposeMotivated by emerging cone-beam computed tomography (CBCT) systems and scan orbits, we aim to quantitatively assess the completeness of data for 3D image reconstruction—in turn, related to “cone-beam artifacts.” Fundamental principles of cone-beam sampling incompleteness are considered with respect to an analytical figure-of-merit [FOM, denoted tan ( ψmin ) ] and related to an empirical FOM (denoted zmod) for measurement of cone-beam artifact magnitude in a test phantom.ApproachA previously proposed analytical FOM [tan ( ψmin ) , defined as the minimum angle between a point in the 3D image reconstruction and the x-ray source over the scan orbit] was analyzed for a variety of CBCT geometries. A physical test phantom was configured with parallel disk pairs (perpendicular to the z-axis) at various locations throughout the field of view, quantifying cone-beam artifact magnitude in terms of zmod (the relative signal modulation between the disks). Two CBCT systems were considered: an interventional C-arm (Cios Spin 3D; Siemens Healthineers, Forcheim Germany) and a musculoskeletal extremity scanner; Onsight3D, Carestream Health, Rochester, United States)]. Simulations and physical experiments were conducted for various source–detector orbits: (a) a conventional 360 deg circular orbit, (b) tilted and untilted semi-circular (196 deg) orbits, (c) multi-source (three x-ray sources distributed along the z axis) semi-circular orbits, and (d) a non-circular (sine-on-sphere, SoS) orbit. The incompleteness of sampling [tan ( ψmin ) ] and magnitude of cone-beam artifacts (zmod) were evaluated for each system and orbit.ResultsThe results show visually and quantitatively the effect of system geometry and scan orbit on cone-beam sampling effects, demonstrating the relationship between analytical tan ( ψmin ) and empirical zmod. Advanced source–detector orbits (e.g., three-source and SoS orbits) exhibited superior sampling completeness as quantified by both the analytical and the empirical FOMs. The test phantom and zmod metric were sensitive to variations in CBCT system geometry and scan orbit and provided a surrogate measure of underlying sampling completeness.ConclusionFor a given system geometry and source–detector orbit, cone-beam sampling completeness can be quantified analytically (in terms arising from Tuy’s condition) and/or empirically (using a test phantom for quantification of cone-beam artifacts). Such analysis provides theoretical and practical insight on sampling effects and the completeness of data for emerging CBCT systems and scan trajectories.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cone-beam CT sampling incompleteness: analytical and empirical studies of emerging systems and source–detector orbits

Tersol

Clackdoyle

et al. 2023

J. Med. Imag.

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“…It was pointed out in [28] that this metric provided necessary completeness condition (which is equivalent to saying the metric provides a sufficient incompleteness condition). Other variations include averaging | cos ψ i | over all (so a value of 1 at location x indicates data completeness) [24], and taking the maximum value of| sin ψ i | over all θ as an incompleteness metric [31]. The metric we propose here has been previously described in conference proceedings papers [18], [17], [19], [46] but as a heuristic approach to defining resolution in tomographic reconstructions.…”

Section: Discussionmentioning

confidence: 99%

“…In 2010, Stopp et al proposed an "image recording quality measure" q(x) for applications in limited-angle X-ray scanning [24]. The quality measure q(x) was similar in spirit to an averaged version of R(x, θ) described above.…”

Section: Introductionmentioning

confidence: 99%

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Quantification of Tomographic Incompleteness in Cone-Beam Reconstruction

Clackdoyle

Noo

2020

IEEE Trans. Radiat. Plasma Med. Sci.

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For situations of cone-beam scanning where the measurements are incomplete, we propose a method to quantify the severity of the missing information at each voxel. This incompleteness metric is geometric; it uses only the relative locations of all cone-beam vertices with respect to the voxel in question, and does not apply global information such as the object extent or the pattern of incompleteness of other voxels. The values are non-negative, with zero indicating "least incompleteness," i.e. minimal danger of incompleteness artifacts. The incompleteness value can be related to the severity of the potential reconstruction artifact at the voxel location, independent of reconstruction algorithm. We performed a computer simulation of x-ray sources along a circular trajectory, and used small multi-disk test-objects to examine the local effects of data incompleteness. The observed behavior of the reconstructed test-objects quantitatively matched the precalculated incompleteness values. A second simulation of a hypothetical SPECT breast imaging system used only 12 pinholes. Reconstructions were performed using analytic and iterative methods, and five reconstructed test-objects matched the behavior predicted by the incompleteness model. The model is based on known sufficiency conditions for data incompleteness, and provides strong predictive guidance for what can go wrong with incomplete cone-beam data.

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Bildgebung und Bildverarbeitung

2010

Biomedizinische Technik/Biomedical Engineering

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Magnetrelaxometrie (MRX) ist eine spezifische Messmethode zur Detektion des Zerfalls der Magnetisierung eines Ensembles von Nanopartikeln, nachdem ein Magnetisierungsfeld abgeschaltet wurde. Als Sensoren für MRX können hochempfindliche supraleitende Quanteninterferometer (SQUIDs) verwendet werden. Wir präsentieren ein Konzept, wie quantitative dreidimensionale Bilder der Verteilung magnetischer Nanopartikel in biologischem Gewebe durch die Kombination der SQUID-Messtechnik mit multiplen räumlich inhomogenen Magnetisierungsfeldern erzielt werden können. Das inverse Problem der Bildrekonstruktion wird durch die Kombination der unterschiedlichen Magnetisierungsfelder stabilisiert. Als Beispiel wurde ein Shepp-Logan-Phantom mit 4096 Voxeln und 10x10x10 cm 3 Volumen bei einem Signal-zu-Rausch-Verhältnis von 250 numerisch rekonstruiert.

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Quality evaluation of image recording strategies for limited angle tomography

Cited by 3 publications

References 8 publications

Cone-beam CT sampling incompleteness: analytical and empirical studies of emerging systems and source–detector orbits

Cone-beam CT sampling incompleteness: analytical and empirical studies of emerging systems and source–detector orbits

Quantification of Tomographic Incompleteness in Cone-Beam Reconstruction

Bildgebung und Bildverarbeitung

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