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Chronic obstructive pulmonary disease (COPD) is increasingly being recognized as a highly heterogeneous disorder, composed of varying pathobiology. Accurate detection of COPD subtypes by image biomarkers is urgently needed to enable individualized treatment, thus improving patient outcome. We adapted the parametric response map (PRM), a voxel-wise image analysis technique, for assessing COPD phenotype. We analyzed whole-lung computed tomography (CT) scans acquired at inspiration and expiration of 194 individuals with COPD from the COPDGene study. PRM identified the extent of functional small airways disease (fSAD) and emphysema as well as provided CT-based evidence that supports the concept that fSAD precedes emphysema with increasing COPD severity. PRM is a versatile imaging biomarker capable of diagnosing disease extent and phenotype while providing detailed spatial information of disease distribution and location. PRM's ability to differentiate between specific COPD phenotypes will allow for more accurate diagnosis of individual patients, complementing standard clinical techniques., COPD is an increasingly prevalent disorder characterized by incompletely reversible airflow limitation (1), (2). Presently, it is the fourth leading cause of death in the United States, with over 11 [...]

Here we describe the parametric response map (PRM), a voxel-wise approach for image analysis and quantification of hemodynamic alterations during treatment for 44 patients with high-grade glioma. Relative cerebral blood volume (rCBV) and flow (rCBF) maps were acquired before treatment and after 1 and 3 weeks of therapy. We compared the standard approach using region-of-interest analysis for change in rCBV or rCBF to the change in perfusion parameters on the basis of PRM ([PRM.sub.rcBV] and [PRM.sub.rcBF]) for their accuracy in predicting overall survival. Neither the percentage change of rCBV or rCBF predicted survival, whereas the regional response evaluations made on the basis of PRM were highly predictive of survival. Even when accounting for baseline rCBV, which is prognostic, [PRM.sub.rcBV] proved more predictive of overall survival., Functional imaging approaches complement anatomical magnetic resonance imaging (MRI) scans and are increasingly being evaluated in oncology practice for diagnosis and assessment of treatment response (1-3). Dynamic contrast-enhanced and dynamic [...]

Byline: Giuseppina D'Agostino (Osgoode Hall Law School of York University, 1-19 Foxchase Avenue, Vaughan, Ontario, L4L 9M9 Canada); Chris Hinds (Oxford University Computing Laboratory, Wolfson Building, Parks Rd, Oxford OX1 [...]

A monochromatic X-ray self-emission imaging diagnostic has been developed for the Z accelerator, which drives 20 MA in 100 ns to implode wire array Z-pinches, generating up to 250 TW of soft X-ray radiation. This instrument reflects eight pinhole images from a flat Cr/C multilayer mirror (MLM) onto a 1-ns time-resolved microchannel plate detector. The MLM reflects 277-eV photons with ~5-eV bandwidth and 20% peak reflectivity, and an aluminized parylene filter shields the detector from visible light. High-energy bremsstrahlung X-rays do not follow the reflected beam path, and so the background on the shielded detector is reduced compared to a standard pinhole camera. The MLM-reflected images offer low-photon-energy spectral resolution that filtration alone cannot, yielding high-quality images of the final stages of the Z-pinch implosion. Initial data on Z from a Cu wire array will be presented. Observed phenomena include implosion instabilities, zippered implosion of a piston onto a pre-cursor column during the onset of stagnation, accretion of trailing colder mass during the X-ray pulse, and cathode reemission. The inferred implosion velocity is significantly less than thin-shell implosion model calculations, and well below what is required for efficient Cu K-shell radiation. Instability-dominated, bright-spot Cu K-shell emission is seen on a second adjacent eight-frame filtered pinhole camera that is in the same beamline. Index Terms--Magnetohydrodynamics, nonhomogenous media, plasma measurements, plasma pinch, K-shell radiation, X-ray imaging, X-ray ineasurements, X-ray production.

There have been significant efforts to build a probabilistic atlas of the brain and to use it for many common applications, such as segmentation and registration. Though the work related to brain atlases can be applied to nonbrain organs, less attention has been paid to actually building an atlas for organs other than the brain. Motivated by the automatic identification of normal organs for applications in radiation therapy treatment planning, we present a method to construct a probabilistic atlas of an abdomen consisting of four organs (i.e., liver, kidneys, and spinal cord). Using 32 noncontrast abdominal computed tomography (CT) scans, 31 were mapped onto one individual scan using thin plate spline as the warping transform and mutual information (MI) as the similarity measure. Except for an initial coarse placement of four control points by the operators, the MI-based registration was automatic. Additionally, the four organs in each of the 32 CT data sets were manually segmented. The manual segmentations were warped onto the 'standard' patient space using the same transform computed from their gray scale CT data set and a probabilistic atlas was calculated. Then, the atlas was used to aid the segmentation of low-contrast organs in an additional 20 CT data sets not included in the atlas. By incorporating the atlas information into the Bayesian framework, segmentation results clearly showed improvements over a standard unsupervised segmentation method. Index Terms--Abdomen scan, probabilistic atlas, segmentation, thin plate spline (TPS).