4D-CT is an important tool for treatment simulation and treatment planning in radiotherapy. In order to capture the tumor and tissue movement over time, 4D-CT has to acquire more projection images compared to 3D-CT. This leads to more radiation dose, which is the main concern of the application. Using fewer projections can reduce the radiation dose. However, lack of projections degrades the rec...

Four-dimensional, cone-beam CT (4D CBCT) substantially reduces respiration-induced motion blurring artifacts in three-dimension (3D) CBCT. However, the image quality of 4D CBCT is significantly degraded which may affect its accuracy in localizing a mobile tumor for high-precision, image-guided radiation therapy (IGRT). The purpose of this study was to investigate the impact of scanning paramete...

In automotive industry, an increasing demand on 3D surface reconstruction from high-speed camera images can be observed, e.g. in car safety testing environments. The paper deals with the automatic photogrammetric measurement of free-form surfaces from synchronous stereo and multi-image sequences as they are required for dynamic area-based deformation analysis. Firstly, instrumental solutions fo...

Respiratory motion causes artifacts in slow-rotating cone-beam (CB) computed tomography (CT) images acquired for example for image guidance of radiotherapy. Respiration-correlated CBCT has been proposed to correct for the respiratory motion, but the use of a subset of the CB projections to reconstruct each frame of the 4D CBCT image limits their quality, thus requiring a longer acquisition time...

BACKGROUND Respiration-correlated CT (4D CT) is the basis of radiotherapy treatment planning of thoracic and abdominal tumors. Current clinical 4D CT images suffer, however, from artifacts due to unfulfilled assumptions concerning breathing pattern regularity. We propose and evaluate modifications to existing low-pitch spiral 4D CT reconstruction protocols to counteract respective artifacts. ...

Due to high noise levels in the voxel kinetics, development of reliable parametric imaging algorithms remains one of most active areas in dynamic brain PET imaging, which in the vast majority of cases involves receptor/transporter studies with reversibly binding tracers. As such, the focus of this work has been to develop a novel direct 4D parametric image reconstruction scheme for such tracers...

A variety of imaging methodologies are being used to collect data for quantitative studies of plant growth and development from living plants. Multi-level data, from macroscopic to molecular, and from weeks to seconds, can be acquired. Furthermore, advances in parallelized and automated image acquisition enable the throughput to capture images from large populations of plants under specific gro...

Light field photography has gained a significant research interest in the last two decades; today, commercial light field cameras are widely available. Nevertheless, most existing acquisition approaches either multiplex a low-resolution light field into a single 2D sensor image or require multiple photographs to be taken for acquiring a high-resolution light field. We propose a compressive ligh...

Accurate delineation of the volumetric motion of left ventri-cle (LV) of the heart over time from tagged MRI is an important area of research. We have built a system that takes tagged short-axis (SA) and long-axis (LA) image sequences as input, ts a 4D B-spline model to the LV of the heart by simultaneously tting knot solids to the SA and LA frame sequences via matching 3 sequences of model kno...