PURPOSE This aim of this paper is to revisit the parallel-beam/cone-beam or fan-beam/cone-beam imaging configuration, and to investigate whether this configuration has any advantages. METHODS Twenty years ago, it was suggested to simultaneously use a parallel-beam (or a fan-beam) collimator and a cone-beam collimator to acquire single photon emission computed tomography data. The motivation w...

Space Dynamics Laboratory at Utah State University (SDL/IJSU) optimized the focus of an off-axis, cryogenically cooled infrared collimator for cryogenic operating temperatures. Historically, collimator focus was optimized at ambient temperatures where interactive focus adjustment and testing coulà be performed. The focus shift that occurred when the optics were cooled was minimized by collimato...

EGS is a very popular Monte Carlo code, used in the simulation of Nuclear Medicine devices. Simulation techniques are particularly effective to optimize collimator configuration and camera design in Single Photon Emission studies. With the EGS code, users must define the geometry where particles are transported. This can be both a very hard task and a source of inefficiency, especially in the c...

Radiologic studies of the nasolacrimal system following instillation of various opaque media have been found to be of value in patients with epiphora. However, there are certain disadvantages with these methods. Extravasation of the oily opaque media into the surrounding tissues may subsequently result in the development of pseudopolycystic sacs. The use of too highly concentrated solutions of ...

UNLABELLED (99m)Tc-sestamibi dual-phase scintigraphy is currently established for parathyroid localization. However, the imaging technique is not standardized, and the role of the pinhole collimator, especially, is not fully recognized in the imaging protocol. The aim of this study was to check whether the use of a pinhole collimator in parathyroid scintigraphy would enhance lesion detectabilit...

More and more camera concepts are being investigated to try and seize the opportunity of instantaneous range verification of proton therapy treatments offered by prompt gammas emitted along the proton tracks. Focusing on one-dimensional imaging with a passive collimator, the present study experimentally compared in combination with the first, clinically compatible, dedicated camera device the p...

UNLABELLED The Society of Nuclear Medicine (SNM) published procedure guidelines for thyroid imaging in 1999. We wished to determine how many clinics performing thyroid imaging follow the guidelines and to what extent. Of particular interest to us was the choice of collimator. METHODS We developed a 10-question survey to obtain information on how hospitals perform thyroid imaging. The question...

We evaluation basic characteristics of a compact type semiconductor gamma camera (eZ-SCOPE AN) of Cadmium Zinc Telluride (CdZnTe). This new compact gamma camera has 256 semiconductors representing the same number of pixels. Each semiconductor is 2 mm square and is located in 16 lines and rows on the surface of the detector. The specific performance characteristics were evaluated in the study re...

PURPOSE Investigation of a reduced source to target distance to improve organ at risk sparing during stereotactic irradiation (STX). METHODS The authors present a planning study with perfectly target-volume adapted collimator compared with multi-leaf collimator (MLC) at reduced source to virtual isocentre distance (SVID) in contrast to normal source to isocentre distance (SID) for stereotacti...