UNLABELLED The aim of this study was to evaluate the imaging performance of 39- and 52-ring time-of-flight (TOF) PET/CT scanners. We also assessed the potential of reducing the scanning time using a 52-ring TOF PET/CT scanner. METHODS PET/CT scanners with 39- and 52-ring lutetium oxyorthosilicate detectors were evaluated. The axial fields of view were 16.2 and 21.6 cm, respectively. We used a...

There is a serious and growing concern about the CT dose delivered by diagnostic CT examinations or image-guided radiation therapy imaging procedures. To better understand and to accurately quantify radiation dose due to CT imaging, Monte Carlo based CT scanner models are needed. This dissertation describes the development, validation, and application of detailed CT scanner models including a G...

GE Healthcare, Waukesha, USA A new ToF-PET/MR scanner has recently been deployed at the University Hospital of Zurich for clinical evaluation purposes. The goal of the present work was to compare the image quality obtained on this system with that of equivalent state-of-the-art standalone scanners. The GE Signa PET/MR is a whole-body scanner combining a 3T wide-bore MR system with a 25 cm PET d...

We present the prototype of an image-guided robotic system for accurate and consistent placement of percutaneous needles in soft-tissue targets under CT guidance inside the gantry of a CT scanner. The couch-mounted system consists of a seven-degrees-of-freedom passive mounting arm, a remote center-of-motion robot, and a motorized needle-insertion device. Single-image-based coregistration of the...

Relative abundance of tumour angiogenesis has been shown to be of clinical relevance in cancers of various locations such as the ovary. Nevertheless, several problems are encountered when quantifying tumour microvessels: (i) as many other tumour markers, vascularity pattern is often heterogeneous within the tumour mass and even within the same histological section. As a consequence, an adequate...

Laser range scanners provide rapid and accurate non-contact methods for acquiring three-dimensional surface data, offering many advantages over other techniques currently available during surgery. The range scanner was incorporated into our image-guided surgery system to augment registration and deformation compensation. A rigid body, embedded with infrared diodes, was attached to the scanner f...

Considering the high cost of dedicated small-animal positron emission tomography/computed tomography (PET/CT), an acceptable alternative in many situations might be clinical PET/CT. However, spatial resolution and image quality are of concern. The utility of clinical PET/CT for small-animal research and image quality improvements from super-resolution (spatial subsampling) were investigated. Na...

The registration and geometric recti cation of airborne scanner imagery is an essential prerequisite for the processing and analysis of this type of images. The Digital Photogrammetric Assembly (DPA) is an airborne camera consisting of three pan-chromatic line arrays for stereo imaging and four line arrays for multi-spectral imaging. For georeferencing the sensor system is completed by a module...

Introduction: Micro-CT scanner with a resolution of about 5 micrometers is one of the modalities used to create three-dimensional/two-dimensional images of urinary stones. This study aimed to optimize imaging parameters in micro-computed tomography (CT) scanner based on the signal-to-noise ratio (SNR) of urinary stones for the analysis of stone composition. <stro...

In this paper we investigate the use of the Poisson model in the creation and the description of binary textures, in conjunction with two forms of image scanning, namely raster and Hilbert scan. We apply our model to some binary random textures for which we estimate the Poisson parameters using Maximum Likelihood Estimation and nd that the values we obtain are suuciently distinct and suuciently...