A long bore fan beam collimator for imaging the head was designed and constructed for a SPECT system with a rotating scintillation camera. In order to avoid the patient's shoulder during rotation of the camera with a thick camera housing, the long bore design is necessary to allow the collimator to get close to the patient's head for improved spatial resolution. Operating at the minimum radius ...

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...

PURPOSE AND METHODS The noninvasive microsphere (NIMS) method quantifies cerebral blood flow with N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) without blood sampling of a patient, but when a fan beam collimator is used for collecting raw data in single photon emission computed tomography (SPECT), the procedure is complicated because we have to change the collimator. In phantom and clinical s...

objective(s): a novel iq-specttm method has become widely used in clinical studies. the present study compares the quality of myocardial perfusion images (mpi) acquired using the iq-specttm (iq-mode),conventional (180° apart: c-mode) and l-mode (90° apart: l-mode) systems. we assessed spatial resolution, image reproducibility and quantifiability using various physical phantoms. materials and me...

Fan-beam collimators are used in single-photon-emission computed tomography (SPECT) to improve the sensitivity for imaging of small organs. The disadvantage of fan-beam collimation is the truncation of projection data surrounding the organ of interest or, in those cases of imaging large patients, of the organ itself, producing reconstruction artifacts. A spatially varying focal length fan-beam ...

Inverting the exponential Radon transform has a potential use for SPECT (single photon emission computed tomography) imaging in cases where a uniform attenuation can be approximated, such as in brain and abdominal imaging. Tretiak and Metz derived in the frequency domain an explicit inversion formula for the exponential Radon transform in two dimensions for parallel-beam collimator geometry. Pr...

Fan-beam collimators are used in single photon emission computed tomography to improve the sensitivity for imaging of small organs. The disadvantage of fan-beam collimation is the truncation of projection data surrounding the organ of interest or, in those cases of imaging large patients, of the organ itself producing reconstruction artifacts. A spatially varying focal length fan-beam collimato...

objective: iqspect is an advanced high-speed spect modality for performing myocardial perfusion imaging (mpi), which uses a multi-focus fan beam collimator with resolution recovery reconstruction. the aim of this study was to compare iqspect compared with conventional spect interms of performance based on standard clinical protocols. in addition, we examined the concordance between conventional...

The modeling of 3D Compton scatter in SPECT is complicated by the use of a variety of collimator geometry. To date, effective and efficient modeling of 3D Compton scatter in parallel-beam SPECT has been made possible by Frey and Tsui [1], Zeng et al [2], and Bai et al [3]. For fan-beam and cone-beam SPECT, the model in [3] can effectively model first order 3D Compton scatter. But for varying-fo...

99mTc methoxyisobutylisonitrile planar scintimammography (SMM) is mostly performed using low-energy high-resolution (LEHR) parallel collimators. We studied whether using a different collimator could improve the detection of small (< 1.5 cm) lesions for which SMM sensitivity is poor. Thirty four breast phantom configurations were considered, either with hot spheres simulating lesions or without ...