Performance and results of the RICH detector for kaon physics in Hall A at Jefferson Lab

Abstract A proximity focusing RICH detector has been constructed for the hadron High Resolution Spectrometer (HRS) of Jefferson Lab Experimental Hall-A. This detector is intended to provide excellent hadron identification up to a momentum of 2.5 GeV / c . The RICH uses a 15 mm thick liquid perfluorohexane radiator in proximity focusing geometry to produce Cherenkov photons traversing a 100 mm thick proximity gap filled with pure methane and converted into electrons by a thin film of CsI deposited on the cathode plane of a MWPC. The detector has been successfully employed in the fixed target, high luminosity and high resolution hypernuclear spectroscopy experiment. With its use as a kaon identifier in the 2 GeV / c region, the very large contribution from pions and protons to the hypernuclear spectrum was reduced to a negligible level. The basic parameters and the resulting performance obtained during the experiment are reported in this paper

Gamma-guided stereotactic breast biopsy system

A gamma-ray imaging system has been developed for acquiring stereo images of the distribution of radiopharmaceuticals in breast tissue. The system consists of a small field-of-view gamma-ray camera mounted to a stereotactic biopsy table. The camera is mounted on a rotational arm such that it can be used to image the breast from two 15° stereo views. These stereo images can be used to determine the three dimensional spatial location of a region of focal uptake. Once the location of this region is determined, this information can be used as a guide for stereotactic core needle biopsy. The accuracy that the spatial location of a source can be determined was investigated by moving a point source within the field of view. A center-of gravity calculation was used to localize the centroid of the image of the source and this was used to determine the spatial location. Measurements indicate that the source can be localized to within 1 mm. A comparison of the operation of the gamma imaging system and an x-ray imaging system has been done using a dual modality phantom. These measurements indicated that the spatial location of an isolated source can be determined by the gamma imaging system to within approximately the same performance criteria as required for the X-ray system (1 mm). Collimators were tested to determine the spatial resolution in the transverse dimension and the impact of this transverse resolution on the axial resolution was investigated. The performance of this gamma-guided stereotactic biopsy system will be presented. © 2006 IEEE

Small field-of-view gamma camera for stereotactic breast biopsy

A gamma-ray imaging system has been developed for acquiring stereo images of the distribution of radiopharmaceuticals in breast tissue. The system consists of a small field-of-view gamma-ray camera mounted to a stereotactic biopsy table. The camera is mounted on a rotational arm such that it can be used to image the breast from two 15° stereo views. These stereo images can be used to determine the three dimensional spatial location of a region of focal uptake. Once the location of this region is determined, this information can be used as a guide for stereotactic core needle biopsy. The accuracy that the spatial location of a source could be determined was investigated by moving a point source within the field of view. Measurements indicate that the source could be localized to within 1 mm. A center-of gravity calculation was used to localize the centroid of the image of the source and this was used to determine the spatial location. A comparison of the operation of the gamma imaging system and an x-ray imaging system has been done using a dual modality phantom. These measurements indicate that the spatial location of an isolated source can be determined by the gamma imaging system to within approximately the same accuracy as the x-ray system. Collimators were tested to determine the spatial resolution in the transverse dimension and the impact of this transverse resolution on the axial resolution was investigated. The performance of this gamma-guided stereotactic biopsy system will be presented. © 2004 IEEE

Gamma-guided stereotactic breast biopsy system

A gamma-ray imaging system has been developed for acquiring stereo images of the distribution of radiopharmaceuticals in breast tissue. The system consists of a small field-of-view gamma-ray camera mounted to a stereotactic biopsy table. The camera is mounted on a rotational arm such that it can be used to image the breast from two 15° stereo views. These stereo images can be used to determine the three dimensional spatial location of a region of focal uptake. Once the location of this region is determined, this information can be used as a guide for stereotactic core needle biopsy. The accuracy that the spatial location of a source can be determined was investigated by moving a point source within the field of view. A center-of gravity calculation was used to localize the centroid of the image of the source and this was used to determine the spatial location. Measurements indicate that the source can be localized to within 1 mm. A comparison of the operation of the gamma imaging system and an x-ray imaging system has been done using a dual modality phantom. These measurements indicated that the spatial location of an isolated source can be determined by the gamma imaging system to within approximately the same performance criteria as required for the X-ray system (1 mm). Collimators were tested to determine the spatial resolution in the transverse dimension and the impact of this transverse resolution on the axial resolution was investigated. The performance of this gamma-guided stereotactic biopsy system will be presented. © 2006 IEEE

Does Distanced Self-Talk Facilitate Emotion Regulation Across a Range of Emotionally Intense Experiences?

Research indicates that a subtle shift in language—silently referring to oneself using one’s own name and non–first-person-singular pronouns (i.e., distanced self-talk)—promotes emotion regulation. Yet it remains unclear whether the efficacy of distanced self-talk depends on the intensity of the negative experience reflected on and whether the benefits extend to emotionally vulnerable individuals. Two high-powered experiments addressed these issues. Distanced as opposed to immersed self-talk reduced emotional reactivity when people reflected on negative experiences that varied in their emotional intensity. These findings held when participants focused on future and past autobiographical events and when they scored high on individual difference measures of emotional vulnerability. The results also generalized across various types of negative events. These findings illuminate the functionality of language for allowing people to regulate their emotions when reflecting on negative experiences across the spectrum of emotional intensity and highlight the need for future research to examine the clinical implications of this techniqu