The use of monolithic scintillator-based photon detectors in positron emission tomography (PET) has emerged as an attractive alternative to traditional pixelated array designs. Monolithic-based detector designs employ the scintillation light distribution (LD) shape provide a single 3-D interaction position per event, enabling high spatial resolution throughout crystal volume. Since there are no intercrystal gaps, higher intrinsic detection efficiency compared However, order make design...

List-mode processing provides an efficient way to deal with sparse projections in iterative image reconstruction for emission tomography. An issue often reported is the tremendous amount of computation required by such algorithm. Each recorded event requires several back- and forward line projections. We investigated use programmable graphics unit (GPU) accelerate line-projection operations implement fully-3D list-mode ordered-subsets expectation-maximization positron tomography (PET)....

We studied the performance of a dual‐panel positron emission tomography (PET) camera dedicated to breast cancer imaging using Monte Carlo simulation. The PET under development has two plates that are constructed from arrays LSO crystals coupled novel ultra‐thin silicon position‐sensitive avalanche photodiodes (PSAPD). In this design photodetectors configured “edge‐on” with respect incoming photons which encounter minimum thick directly measured photon interaction depth. Simulations predict...

Abstract Following the discovery of X-rays, scintillators are commonly used as high-energy radiation sensors in diagnostic medical imaging, physics, astrophysics, environmental monitoring, and security inspections. Conventional face intrinsic limitations including a low extraction efficiency scintillated light emission rate, leading to efficiencies that less than 10 % for commercial scintillators. Overcoming these will require new materials scintillating nanomaterials (“nanoscintillators”),...

The kinematics of Compton scatter can be used to estimate the interaction sequence inter-crystal interactions in 3D position-sensitive cadmium zinc telluride (CZT) detectors. However, case intra-crystal a 'cross-strip' CZT detector slab, multiple anode and cathode strips may triggered, creating position ambiguity due uncertainty possible combinations anode–cathode pairings. As consequence, methods such as energy-weighted centroid are not applicable interactions. In practice, since event is...

X-ray fluorescence imaging is a promising technique able to depict the spatial distributions of low amounts molecular agents in vivo. Currently, translation preclinical and clinical applications hindered by long scanning times as objects are scanned with flux-limited narrow pencil beams. The study presents novel approach combining x-ray Compton imaging. cameras leverage performance XFCT abolish need for beam excitation. examines potential this new on base Monte-Carlo simulations. In work, it...

Advanced list-mode image reconstruction algorithms such as fully 3D ordered-subset expectation maximization (OSEM) are needed to exploit the potential performance of high-resolution PET systems with depth-of-interaction capabilities. However, computationally intensive. With aim accelerate 3D-OSEM, we investigated use graphics processing units (GPUs). Primarily designed deliver high-definition for video games in realtime, GPUs now increasingly being used cost-effective high-performance...

Nuclear medicine imaging detectors are commonly multiplexed to reduce the number of readout channels. Because underlying detector signals have a sparse representation, recovery methods such as compressed sensing may be used develop new multiplexing schemes. Random create matrices that satisfy restricted isometry property. However, property provides little guidance for developing networks with good signal-to-noise capability. In this work, we describe using maximum likelihood framework and...

Compressed sensing can be used to multiplex a large number of individual readout sensors significantly reduce the channels in area PET block detector. The compressed framework treat data acquisition as sparse problem and achieve sub-Nyquist rate sampling, where Nyquist is determined by pixel pitch SiPM sensors. matrix fabricated using discrete elements or wires that uniquely connect pixels channels. By analyzing recorded magnitude on several ADC channels, original values recovered even...

Advances in solid-state technology have enabled the development of silicon photomultiplier sensor arrays capable sensing individual photons. Combined with high-frequency time-to-digital converters (TDCs), this opens up prospect sensors recording high accuracy both time and location each detected photon. Such a capability could lead to significant improvements imaging accuracy, especially for applications operating low photon fluxes such as light detection ranging positron-emission...

This work proposes, for the first time, an image-based end-to-end self-normalization framework positron emission tomography (PET) using conditional generative adversarial networks (cGANs).

We are developing cadmium zinc telluride detectors with three-dimensional photon positioning capabilities for high-resolution PET imaging. These exhibit high spatial resolution (1 mm), energy (2.5% full width at half maximum 511 keV photons), and the ability to resolve individual Compton interactions within detector. Using these measurements, non-coincident single photons can be reconstructed by estimating incoming direction of using kinematics scatter In this paper, we investigated image...

In this work, we propose a new method to increase the accuracy of identifying true coincidence events for positron emission tomography (PET). This approach requires 3-D detectors with ability position each photon interaction in multi-interaction events. When multiple interactions occur detector, incident direction can be estimated using Compton scatter kinematics (Compton Collimation). If difference between relative second, coincident lies within certain angular range around colinearity,...

A key parameter in the practical application of filtered back-projection (FBP), standard clinical image reconstruction algorithm for positron emission tomography (PET), is choice a low-pass filter window function and its cut-off frequency. However, windows frequencies are usually chosen empirically, based on small sample images filters. By considering features signal noise spectra sinogram, desired resolution, signal-to-noise ratio (SNR) methodology informed selection frequency FBP was...

We are investigating a new cadmium zinc telluride (CZT) detector module with 0.5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> reconstructed spatial resolution for small animal PET and plant imaging. Inter-pixel scatter will degrade the contrast or, if events discarded, reduce sensitivity. CZT also has poor time leading to reduced from random coincidences. use kinematics of Compton estimate position inter-pixel so that these can be...

We present two novel contributions for multiplexing PET detectors. First, we develop a new theoretical framework investigating schemes detectors using the theory of "compressed sensing" (CS). Second, CS decoder that improves SNR. Because photon events in are discrete, detected signals very sparse. can be used to specify topologies minimize number unique readout channels. In case detector array, determine sampling criteria effective "decoding" individual pixel and guide design readouts....

We present a fast and accurate method for reconstructing single photons detected by Compton camera using 3D cone projection operations formulated to run on graphics processing unit (GPU) the compute unified device architecture (CUDA) framework. With these operations, image quality accuracy of modalities such as positron emission tomography (PET) can be improved incorporating scatter events. also use Monte Carlo simulation produce model blurring effects caused limited energy spatial...

We are developing cadmium zinc telluride detectors with three-dimensional positioning capabilities for high-resolution PET imaging. These exhibit high spatial resolution (1 mm), energy (2.5% full width at half maximum 511 keV photons), and the ability to identify 3-D coordinates of individual Compton photoelectric interactions within detector. can operate in conventional mode measuring photons coincidence as a camera single photon events. In this work, we show how detector be used...

The number of lines response (LOR) in a system with small crystals and depth interaction (DOI) measurement capability can require prohibitive amounts memory computational resources. independent LORs the animal imaging evaluated this study is /spl sim/2 times/ 10/sup 9/. We propose method to adapt component-based normalization model include (1) DOI (2) large field view (FOV) inner bore volume percentage (near 100%) or (POV) considerations without an order magnitude increase This also...

This study investigates the effect of energy threshold on being able to include and position multiple-interaction photon events (MIPEs) detected in a cadmium zinc telluride (CZT) based small animal PET system we have built. Due noise fluctuations, each channel's data acquisition trigger should be adjusted above floor, which limits detection interactions with below threshold. If not identified, these will lead loss sensitivity as well reconstructed image spatial resolution and/or contrast....

In this work, we develop a new method to reject random coincidences and identify true from multiple photon using 3-D positioning PET detectors. We are developing scintillation cadmium zinc telluride (CZT) detectors with the ability position coordinates of every detector interaction 1 mm intrinsic spatial ≪2.5% FWHM energy resolution at 511 keV. For interactions, first two interactions used electronically collimate single photons by kinematics Compton scatter. use "direction window" determine...

We present a context-aware generative deep learning framework to produce photon attenuation and scatter corrected (ASC) PET images directly from non-attenuation non-scatter (NASC) images. trained conditional adversarial networks (cGAN) on either single-modality or multi-modality (NASC+MRI) input data map NASC pixel-wise continuously valued ASC designed evaluated four cGAN models including Pix2Pix, attention-guided (AG-Pix2Pix), vision transformer (ViT-GAN), shifted window (Swin-GAN)....

Simultaneous positron emission tomography (PET)/magnetic resonance imaging provides concurrent information about anatomic, functional, and molecular changes in disease. We are developing a second generation MR-compatible RF-penetrable TOF-PET insert. The insert has smaller scintillation crystal size ring diameter compared to clinical whole-body PET scanners, resulting higher spatial resolution sensitivity. This paper reports the initial system performance of this full-ring global photopeak...