OBJECTIVES Although CT scanners generally allow dynamic acquisition of thin slices (1 mm), thick slice (≥5 mm) reconstruction is commonly used for stroke imaging to reduce data, processing time, and noise level. Thin slice CT perfusion (CTP) reconstruction may suffer less from partial volume effects, and thus yield more accurate quantitative results with increased resolution. Before thin slice ...

The partial volume effect in Positron Emission Tomography (PET) is a problem for quantitative radiotracer studies. This effect results from the limited spatial resolution of the imaging device (a few mm’s). Two factors are involved; the spillover of radioactivity into neighbouring regions and the underlying tissue inhomogeneity of the particular region. Linear methods are currently used to corr...

In this paper, we present an algorithm for detecting partial Euclidean symmetries in volume data. Our algorithm finds subsets in voxel data that map to each other approximately under translations, rotations, and reflections. We implement the search for partial symmetries efficiently and robustly using a feature-based approach: We first reduce the volume to salient line features and then create ...

PET has the invaluable advantage of being intrinsically quantitative, enabling accurate measurements of tracer concentrations in vivo. In PET tumor imaging, indices characterizing tumor uptake, such as standardized uptake values, are becoming increasingly important, especially in the context of monitoring the response to therapy. However, when tracer uptake in small tumors is measured, large bi...

The effect of the volume flow rate of the heat transfer fluid (air) on the thermal parameters of the solar air collector with a single air pass without using fins under the absorbing plate have been investigated experimentally and theoretically. We use a new design of solar air collector which aims to optimize these parameters in the region cited above. Our solar air collector was realized at t...

We propose a fast algorithm to estimate brain tissue concentrations from conventional T1-weighted images based on a Bayesian maximum a posteriori formulation that extends the "mixel" model developed in the 90's. A key observation is the necessity to incorporate additional prior constraints to the "mixel" model for the estimation of plausible concentration maps. Experiments on the ADNI standardi...

BACKGROUND Quantitative myocardial PET perfusion imaging requires partial volume corrections. METHODS Patients underwent ECG-gated, rest-dipyridamole, myocardial perfusion PET using Rb-82 decay corrected in Bq/cc for diastolic, systolic, and combined whole cycle ungated images. Diastolic partial volume correction relative to systole was determined from the systolic/diastolic activity ratio, s...