Computed laminography for materials testing

Zhou, Jianxun; Maisl, Michael; Reiter, H.; Arnold, W.

doi:10.1063/1.115771

Cited by 54 publications

(33 citation statements)

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“…Since it was used in 1970s, much work has been done about CL on the scanning trajectories, reconstruction algorithms and image processing methods [11][12][13][14]. The imaging speed and the image quality have been improved greatly.…”

Section: Introductionmentioning

confidence: 99%

Large field of view computed laminography with the asymmetric rotational scanning geometry

Jiang²,

Li³

2010

Sci. China Technol. Sci.

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X-ray computed laminography (CL) is used in the fields of industrial inspection and medical imaging. It can provide the internal structure three-dimensional (3D) information of a region of the objects nondestructively. It is important to the clinical diagnosis and the quality control of flat objects like printed circuit boards, aircraft wings and satellite solar panels. With the restriction that the imaging region must be within the X-ray beam formed by the X-ray source and the detector, the imaging field of view of CL is limited by the size of detector. A new CL method with an asymmetric rotational cone-beam scanning geometry, called large field of view CL, is presented to overcome the existing disadvantage. It can extend the imaging region when the imaging spatial resolution keeps the same as that of the conventional CL. It can also improve the imaging spatial resolution when the imaging region keeps the same as that of the conventional CL. The asymmetric configuration can be achieved by offsetting the detector from the conventional symmetric configuration. It does not, however, require new detectors and X-ray source nor alter the scanning mechanical system. The filtered back-projection (FBP) reconstruction algorithm and the data truncation smoothing functions have been deduced to reconstruct the images directly from the data acquired with this asymmetric configuration. We performed numerical studies and experiments to demonstrate and validate the proposed approach. Results in these studies and experiments confirm that the proposed method can enlarge the imaging region and improve the spatial resolution. The proposed approach may find applications in the CL system with the rotational scanning geometry. computed laminography, image reconstruction, reconstruction algorithm, imaging field of view, imaging spatial resolution Citation:Fu J, Jiang B H, Li B. Large field of view computed laminography with the asymmetric rotational scanning geometry.

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Section: Introductionmentioning

confidence: 99%

Large field of view computed laminography with the asymmetric rotational scanning geometry

Jiang²,

Li³

2010

Sci. China Technol. Sci.

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“…Nowadays, by combining digital projection data and computerised reconstruction, 9 the scanning procedure can be avoided: this so-called digital tomosynthesis has analogy to CT with limited angle access. Due to the availability of fast two-dimensional (2D) digital detector systems and the tremendous increase of computing power it has recently found renewed interest in medical 9, 10 and technical 11,12 applications. SRCL was inspired by already established methods from medicine (usually called digital tomosynthesis 9 ) and nondestructive device testing (frequently called computed laminography 11,12 ).…”

Section: Introductionmentioning

confidence: 99%

“…Due to the availability of fast two-dimensional (2D) digital detector systems and the tremendous increase of computing power it has recently found renewed interest in medical 9, 10 and technical 11,12 applications. SRCL was inspired by already established methods from medicine (usually called digital tomosynthesis 9 ) and nondestructive device testing (frequently called computed laminography 11,12 ). Synchrotron radiation provides specific advantages for x-ray imaging such as • monochromatic radiation of tunable x-ray energy, for instance in order to avoid beam hardening artefacts, or to select absorption edges of specific chemical elements in the sample,…”

Section: Introductionmentioning

confidence: 99%

High-resolution three-dimensional imaging by synchrotron-radiation computed laminography

et al. 2006

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The methodical development and first instrumental implementation of computed laminography / tomosynthesis using synchrotron radiation are presented. The technique was developed for three-dimensional imaging of flat and laterally extended objects with high spatial resolution. This paper introduces the fundamental principle of the imaging process and discusses the method's particularities in comparison to computed tomography and computed laminography / digital tomosynthesis.Introducing a simple scanning geometry adapted to the particular experimental conditions of synchrotron imaging set-ups (such as the stationary source and a parallel beam) allows us to combine the advantages of laminography and those provided by synchrotron radiation, for instance monochromatic radiation in order to avoid beam hardening artefacts, high beam intensity for achieving high spatial resolution and fast scanning times or spatial coherence for exploiting phase contrast.The potential of the method for three-dimensional imaging of microelectronic devices is demonstrated by examples of flip-chip bonded and wire-bonded devices.

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“…In the last two decades, other trajectories are also presented and studied, such as asymmetric fan-beam imaging configurations, 1 a saddle trajectory for cardiac CT imaging, 2 straight-line trajectories for tomosynthesis or CT imaging, [3][4][5][6][7][8] and other free-form trajectories. 9 To better fulfill the requirement in industrial fields, imaging configurations with straight-line trajectories may be useful.…”

Section: Introductionmentioning

confidence: 99%

Direct filtered-backprojection-type reconstruction from a straight-line trajectory

et al. 2007

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A computed tomography ͑CT͒ imaging configuration with a straight-line trajectory is investigated, and a direct filtered backprojection ͑FBP͒ algorithm is presented. This kind of system may be useful for industrial applications and security inspections. Projections from a straight-line trajectory have a special property where data from each detector element correspond to a parallel-beam projection of a certain view angle. However, the sampling steps of parallel beams differ from view to view. Rebinning raw projections into uniformly sampled parallelbeam projections is a common choice for this type of reconstruction problem. However, the rebinning procedure suffers a loss of spatial resolution because of interpolations. Our reconstruction method is first derived from the Fourier slice theorem, where a coordinate transform and geometrical relations in projection and backprojection are used. It is then extended to 3-D scanning geometry. Finally, data-shift preprocessing is proposed to reduce computation and memory requirements by removing useless projections in raw data. In this method, the spatial resolution is better preserved and the reconstruction is less sensitive to data truncation than in the rebinning-to-parallel-beam method. To deal with limited angle problem, an iterative reconstruction reprojection method is introduced to estimate missing data and improve the image quality.

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Computed laminography for materials testing

Cited by 54 publications

References 0 publications

Large field of view computed laminography with the asymmetric rotational scanning geometry

Large field of view computed laminography with the asymmetric rotational scanning geometry

High-resolution three-dimensional imaging by synchrotron-radiation computed laminography

Direct filtered-backprojection-type reconstruction from a straight-line trajectory

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