Current Concepts of Metabolic Functional Imaging with Positron Emitters

Positron emitting radionuclides have unique properties that make them nearly ideal as radioactive tracers for in vivo metabolic studies. Using positron emission tomographic (PET) scanning and positron-labeled radiopharmaceuticals, one can study local glucose metabolism in tissues, blood flow, oxygen utilization, protein synthesis, and many other functions noninvasively in normal subjects and patients who have various diseases. A review of some of these techniques and the relative advantages and problems associated with the PET approach is presented

Feasibility of sharpening limited-angle tomography by including an orthogonal set of projections

In single photon emission nuclear medicine, computed tomography systems that employ only a limited angular range of projection data suffer from blurring in the depth (or z) direction. With simulated data, we show that including a second set of projections taken in an orthogonal direction sharpens the image in the z direction. For heart applications, this sharpening improves the sizing of a simulated 2 cm diameter "hot" infarct by 39%. It also should improve the contrast of "cold" infarcts by eliminating blurring from other planes, but here we have found a complication, in that, with the present approximate algorithm, effects from the lack of symmetry in two-view tomography may overshadow benefits from contrast improvement. Further simulation study is called for.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24056/1/0000307.pd

Relationship between myocardial perfusion and function following coronary reflow in the canine heart using single photon emission computed tomography and two-dimensional echocardiography

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25660/1/0000212.pd

Noninvasive quantification of jeopardized myocardial mass in dogs using 2-dimensional echocardiography and thallium-201 tomography

The evaluation of jeopardized myocardial mass is important in defining the effect of interventions during myocardial infarction. To quantitate the in vivo mass at risk, 2-dimensional echocardiography (2-D echo) and thallium-201 single-photon emission computed tomography (SPECT) was performed in 10 closed-chest dogs after circumflex coronary artery occlusion. The 2-D images were manually digitized to compute left ventricular (LV) mass using a modified Simpson's rule algorithm. This measure of LV mass correlated well with the actual LV mass (r = 0.97). Perfused myocardial mass was estimated from thallium SPECT images 4 hours after occlusion using a region-growing algorithm. After the dogs were killed, the jeopardized mass was outlined using a dual perfusion staining technique using triphenyltetrazolium chloride and Evans blue dye. The actual perfused mass was well estimated by the thallium images (r = 0.96). The noninvasively determined mass at risk was calculated as: 2-D mass -- thallium SPECT mass, and correlated well with the pathologically determined mass at risk (r = 0.91). Thus, the jeopardized mass may be determined noninvasively by using 2-D echo and thallium-201 tomography. This approach may provide further information regarding the effect of intervention therapy on jeopardized myocardium.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25450/1/0000900.pd

Pericardial effusion swinging heart phenomenon by dynamic radionuclide ventriculography

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24448/1/0000722.pd

Refining trait resilience: identifying engineering, ecological, and adaptive facets from extant measures of resilience

The current paper presents a new measure of trait resilience derived from three common mechanisms identified in ecological theory: Engineering, Ecological and Adaptive (EEA) resilience. Exploratory and confirmatory factor analyses of five existing resilience scales suggest that the three trait resilience facets emerge, and can be reduced to a 12-item scale. The conceptualization and value of EEA resilience within the wider trait and well-being psychology is illustrated in terms of differing relationships with adaptive expressions of the traits of the five-factor personality model and the contribution to well-being after controlling for personality and coping, or over time. The current findings suggest that EEA resilience is a useful and parsimonious model and measure of trait resilience that can readily be placed within wider trait psychology and that is found to contribute to individual well-bein

Registered Ship Notes

https://digitalmaine.com/blue_hill_documents/1179/thumbnail.jp

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure