Phase imaging coupled to micro-tomography acquisition has emerged as a powerful tool to investigate specimens in a non-destructive manner. While the intensity data can be acquired and recorded, the phase information of the signal has to be “retrieved” from the data modulus only. Phase retrieval is an ill-posed non-linear problem and regularization techniques including a priori knowledge are nec...

We focus on the reconstruction of binary functions from a small number of X-ray projections. The linear–programming (LP) relaxation to this combinatorial optimization problem due to Fishburn et al. is extended to objective functionals with quadratic smoothness priors. We show that the regularized LP–relaxation provides a good approximation and thus allows to bias the reconstruction towards solu...

In this paper we improve the behavior of a reconstruction algorithm for binary tomography in the presence of noise. This algorithm which has recently been published is derived from a primal-dual subgradient method leading to a sequence of linear programs. The objective function contains a smoothness prior that favors spatially homogeneous solutions and a concave functional gradually enforcing b...

Image interpolation is ubiquitous for image reconstruction in computed tomography (CT). For instance, the backprojection step of reconstruction algorithms is traditionally implemented with the simple linear interpolation model. This model is approximate but offers a good trade-off between speed and accuracy. Furthermore the implementation is natural and available on hardware graphics processing...

Objective(s): In this study, we aimed to describe the characteristics of portal vein tumor thrombosis (PVTT), complicating hepatocellular carcinoma (HCC) in contrast-enhanced FDG PET/CT scan. Methods: In this retrospective study, 9 HCC patients with FDG-avid PVTT were diagnosed by contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), which is a comb...

Introduction: The success of radiotherapy cancer treatment delivery depends on the accuracy of patient positioning for each treatment session. A number of kilovoltage x-ray volumetric imaging modalities with an additional source and detector have been developed to allow patient set-up verification based on the internal anatomy, but a significant portion of medical linacs are on...

S U M M A R Y Southeast (SE)Asia is a tectonically complex region surrounded bymany active source regions, thus an ideal test bed for developments in seismic tomography. Much recent development in tomography has been based on 3-D sensitivity kernels based on the first-order Born approximation, but there are potential problems with this approach when applied to waveform data. In this study, we d...

In emission tomography, the spatial distribution of a radioactive tracer is estimated from a finite sample of externally detected photons. We present an algorithm-independent theory of statistical accuracy attainable in emission tomography that makes minimal assumptions about the underlying image. Let f denote the tracer density as a function of position (i.e., f is the image being estimated). ...

Electronically controlled coherent linear optical sampling for low coherence interferometry (LCI) and optical coherence tomography (OCT) is demonstrated, using two turn-key commercial mode-locked fiber lasers with synchronized repetition rates. This novel technique prevents repetition rate limitations present in previous implementations based on asynchronous optical sampling. Adjustable scannin...

Electrical Impedance Tomography (EIT) of closed conductive media is an ill-posed inverse problem. As regards the corresponding direct problem, the choice of a Finite Elements Method preserves the non linear dependence of the observation set upon the conductivity distribution. In this paper, we show that the Bayesian approach presented in (1) for linear inverse imaging problems is also valid for...