PURPOSE In this work, we propose a new method of calibrating cone beam computed tomography (CBCT) data sets for radiotherapy dose calculation and plan assessment. The motivation for this patient-specific calibration (PSC) method is to develop an efficient, robust, and accurate CBCT calibration process that is less susceptible to deformable image registration (DIR) errors. METHODS Instead of m...

We represent the sequence of fMRI (Functional Magnetic Resonance Imaging) brain volumes recorded during a cognitive stimulus by a graph which consists of a set of local meshes. The corresponding cognitive process, encoded in the brain, is then represented by these meshes each of which is estimated assuming a linear relationship among the voxel time series in a predefined locality. First, we def...

Intensity value-based registration is a widely used technique for the spatial alignment of medical images. Generally, the registration transformation is determined by iteratively optimizing a similarity measure calculated from the grey values of both images. However, such algorithms may have high computational costs, especially in the case of multi-modality registration, which makes their integ...

In this paper, a new method for estimation of vertical leaf area density (LAD) profile of tree canopy using portable scanning lidar is proposed. In this method, which we refer to as the voxel-based canopy profiling (VCP) method, several measurement points surrounding the canopy and optimally inclined laser beams are adopted to facilitate full laser beam illumination of whole canopy up to the in...

The leaf area density (LAD) within a tree canopy is very important for the understanding and modeling of photosynthetic studies of the tree. Terrestrial light detection and ranging (LiDAR) has been applied to obtain the three-dimensional structural properties of vegetation and estimate the LAD. However, there is concern about the efficiency of available approaches. Thus, the objective of this s...

Introduction The relative anisotropy (RA) exhibits a great contrast between brain white and gray matters [1]. However, RA is susceptible to the influence of noise [2, 3]. Although the proposed inter-voxel indices reduce noise influence on measured diffusion anisotropy [3], the partial volume effect originating from the inter-voxel operation adds uncertainty to the estimated anisotropy depending...

The prime motivation of this work is to devise a projection algorithm that makes the Algebraic Reconstruction Technique (ART) and related methods more efficient for routine clinical use without compromising their accuracy. While we focus mostly on a fast implementation of ART-type methods in the context of 3D cone-beam reconstruction, most of the material presented here is also applicable to sp...