X-ray fluorescence molecular imaging of high-Z tracers: Investigation of a novel analyzer based setup.

A novel x-ray fluorescence imaging setup for The in vivo detection of high-Z Tracer distributions is investigated for its application in molecular imaging. The setup uses an energy resolved detection method based on a Bragg reflecting analyzer array Together with a multiple scatter reducing radial collimator. The aim of This work is To investigate The potential application of This imaging method To in vivo imaging in humans. A proof of principle experiment modeling a partial setup for The detection of gold nano-particles was conducted in order To Test The feasibility of The proposed imaging method. Furthermore a Monte Carlo simulation of The complete setup was created in order To quantify The dependence of The image quality on The applied radiation dose and on The geometrical collimator parameters as well as on The analyzer crystal parameters. The Monte Carlo simulation quantifies The signal-to-noise ratio per radiation dose and its dependence on The collimator parameters. Thereby The parameters needed for a dose efficient in vivo imaging of gold nano-particle based Tracer distributions are quantified. However also a number of problems are found like The fluorescence emission as well as scatter from The collimator material obscuring The Tracer fluorescence and The potentially large scan Time

Molecular imaging based on X-ray fluorescent high-Z tracers.

We propose a novel x-ray fluorescence imaging setup for the in vivo detection of high-Z tracer distributions. The main novel aspect is the use of an analyzer-based, energy-resolved detection method together with a radial, scatter reducing collimator. The aim of this work is to show the feasibility of this method by measuring the Bragg reflected K-fluorescence signal of an iodine solution sample in a proof of principle experiment and to estimate the potential of the complete imaging setup using a Monte Carlo simulation, including a quantification of the minimal detectable tracer concentration for in vivo imaging. The proof of principle experiment shows that even for a small detector area of approximately 7 mm(2), the collimated and Bragg reflected K-fluorescence signal of a sample containing an iodine solution with a concentration of 50 mu g ml(-1) can be detected. The Monte Carlo simulation also shows that the proposed x-ray fluorescence imaging setup has the potential to image distributions of high-Z tracers in vivo at a radiation dose of a few mGy and at tracer concentrations down to 1 mu g ml(-1) for iodine in small animals

Ventilation imaging of the paranasal sinuses using xenon-enhanced dynamic single-energy CT and dual-energy CT: A feasibility study in a nasal cast.

To show the feasibility of dual-energy CT (DECT) and dynamic CT for ventilation imaging of the paranasal sinuses in a nasal cast. In a first trial, xenon gas was administered to a nasal cast with a laminar flow of 7 L/min. Dynamic CT acquisitions of the nasal cavity and the sinuses were performed. This procedure was repeated with pulsating xenon flow. Local xenon concentrations in the different compartments of the model were determined on the basis of the enhancement levels. In a second trial, DECT measurements were performed both during laminar and pulsating xenon administration and the xenon concentrations were quantified directly. Neither with dynamic CT nor DECT could xenon-related enhancement be detected in the sinuses during laminar airflow. Using pulsating flow, dynamic imaging showed a xenon wash-in and wash-out in the sinuses that followed a mono-exponential function with time constants of a few seconds. Accordingly, DECT revealed xenon enhancement in the sinuses only after pulsating xenon administration. The feasibility of xenon-enhanced DECT for ventilation imaging was proven in a nasal cast. The superiority of pulsating gas flow for the administration of gas or aerosolised drugs to the paranasal sinuses was demonstrated. aEuro cent Ventilation of the paranasal sinuses is poorly understood. aEuro cent Dual-energy CT ventilation imaging has been explored using phantom simulation. aEuro cent Xenon can be seen in the paranasal sinuses using pulsating xenon flow. aEuro cent Dual-energy CT uses a lower radiation dose compared with dynamic ventilation CT

Normalising brain PET images

PET is a nuclear medical examination which constructs a three-dimensional image of metabolism inside the body; in this article is particular, images are taken from the brain. The high complexity inherent to the interpretation of the brain images makes that any help is important to the specialists in order to accurate the diagnostic. In orden to reach reliable and good images, a normalizacion precess is suggested in this paper, consisting of contring the brain in the three-dimensional image, scaling it according to a template brain and, finally, rotating the brain according to the inclination of the template. For not reducing the quality of the information the application works with PET image format and radioactivity measures instead of translate to an ordinary colour image