Monte Carlo simulations are used to establish a weighting function that describes the collection of angular scattering for the WETLabs AC-9 reflecting tube absorption meter. The equivalent weighting function for the AC-9 attenuation sensor is found to be well approximated by a binary step function with photons scattered between zero and the collection half-width angle contributing to the scatte...

In CT, the nonlinear attenuation characteristics of polychromatic X-rays cause beam hardening artifacts in the reconstructed images. When datasets contain multiple materials in the field of scan, the performance of state-of-the-art beam hardening correction approaches is limited by high computational load and reduced correction efficiency. An image based multi-material beam hardening correction...

We hypothesize that improved quantification for PET imaging of high atomic number materials can be achieved by combining low-dose x-ray imaging with dual energy CT for PET attenuation correction. Improved quantification of tracer uptake will lead to improved patient outcomes by providing more accurate information for therapeutic choices. Accurate PET/CT measurements of early response will be cr...

The purpose of our study was to assess the role of a 64-slice multidetector CT (MDCT) scanner in the characterization of different solid renal masses, using a simplified approach to correct the postenhancement attenuation values. The study included 96 consecutive adults (58 men, 38 women) with renal masses; 93 with unilateral and three with bilateral masses. All of our patients underwent multip...

X-ray fluorescence computed tomography (XFCT) is an experimental technique that can reconstruct the distribution of elements within the sample from the measurement of fluorescence stimulated from the sample[1]. The sample is irradiated with a x-ray beam, of which the energy is greater than the K-shell energy or L-shell energy of the interest elements. These x rays undergo photoelectric interact...

Progress in imaging and quantification of tissue perfusion using ultrasound (US) and microbubble contrast agents has been undermined by the lack of an effective automatic attenuation correction technique. In this article, an elementary model of the US attenuation processes for microbubble contrast enhanced imaging is developed. In the model, factors such as nonlinear bubble scattering, nonlinea...

Using nuclear medicine techniques, physiologic activity and processes can be identified in a way that is unique from other modalities. Oftentimes it is helpful to know the exact location of the physiologic uptake that is visualized on a scan. Knowing the exact location can sometimes help to distinguish normal from abnormal physiologic uptake. When an abnormality has been identified, knowing the...

2 Cover illustration: The logarithm of a 123 I point spread function. The point source was simulated at 14.0 cm distance from the collimator in air, with the SIMIND version described in Paper V, using parameters corresponding to a GE Millennium MPR with 2.3 × 2.3 m 2 field of view. The grey scale is processed. To Björn, family and friends If you don't care where you are, you ain't lost. ABSTRAC...