Time-resolved imaging of prompt-gamma rays for proton range verification using a knife-edge slit camera based on digital photon counters

Proton range monitoring may facilitate online adaptive proton therapy and improve treatment outcomes. Imaging of proton-induced prompt gamma (PG) rays using a knife-edge slit collimator is currently under investigation as a potential tool for real-time proton range monitoring. A major challenge in collimated PG imaging is the suppression of...

Time-based position estimation in monolithic scintillator detectors

Gamma-ray detectors based on bright monolithic scintillation crystals coupled to pixelated photodetectors are currently being considered for several applications in the medical imaging field. In a typical monolithic detector, both the light intensity and the time of arrival of the earliest scintillation photons can be recorded by each of the...

Geometric optimization of an ultralow-dose high-resolution pediatric PET scanner based on monolithic scintillators with dSiPM readout (meeting abstract)

PSMR 2015: 4th Conference on PET/MR and SPECT/MR, La Biodola, Isola d’Elba, Italy, 17-21 May 2015

Experimental Validation of an Efficient Fan-Beam Calibration Procedure for k -Nearest Neighbor Position Estimation in Monolithic Scintillator Detectors

Monolithic scintillator detectors can achieve excellent spatial resolution and coincidence resolving time. However, their practical use for positron emission tomography (PET) and other applications in the medical imaging field is still limited due to drawbacks of the different methods used to estimate the position of interaction. Common...

Improving the Time Resolution of TOF-PET Detectors by Double-Sided Readout

State-of-the-art scintillation detectors for time-of-flight positron emission tomography (TOF-PET) typically employ scintillation crystals with a high aspect ratio (e.g. 4 ×4 ×22 mm3) read out on one of the small crystal surfaces. This single-sided readout (SSR) geometry may be unfavorable in terms of the coincidence resolving time (CRT) that...

Scintillation properties of Ca co-doped L(Y)SO:Ce between 193 K and 373 K for TOF-PET/MRI

An enhanced high-resolution EMCCD-based gamma camera using SiPM side detection

To improve multi-pinhole single photon emission computed tomography (SPECT) devices we are developing a high-resolution gamma detector consisting of a 3-mm-thick scintillation crystal that converts gamma photons to light, on top of an optically coupled high-resolution, high-sensitivity light sensor (EMCCD). This gamma camera can detect...

A Comprehensive Model of the Response of Silicon Photomultipliers

The response of a silicon photomultiplier (SiPM) to optical signals is inherently nonproportional due to saturation, afterpulsing, and crosstalk. Existing models of the SiPM response do not account for all of these effects, and therefore, these models are not sufficiently accurate for many applications. In this work, a comprehensive model of the...

LaBr3:Ce and SiPMs for time-of-flight PET: Achieving 100 ps coincidence resolving time

The use of time-of-flight (TOF) information in positron emission tomography (PET) enables significant improvement in image noise properties and, therefore, lesion detection. Silicon photomultipliers (SiPMs) are solid-state photosensors that have several advantages over photomultiplier tubes (PMTs). SiPMs are small, essentially transparent to 511...

Optical simulation of monolithic scintillator detectors using GATE/GEANT4

Much research is being conducted on position-sensitive scintillation detectors for medical imaging, particularly for emission tomography. Monte Carlo simulations play an essential role in many of these research activities. As the scintillation process, the transport of scintillation photons through the crystal(s), and the conversion of these...

Simulation of silicon photomultiplier signals

In a silicon photomultiplier (SiPM), also referred to as multi-pixel photon counter (MPPC), many Geiger-mode avalanche photodiodes (GM-APDs) are connected in parallel so as to combine the photon counting capabilities of each of these so-called microcells into a proportional light sensor. The discharge of a single microcell is relatively well...

A novel, SiPM-array-based, monolithic scintillator detector for PET

Silicon photomultipliers (SiPMs) are of great interest to positron emission tomography (PET), as they enable new detector geometries, for e.g., depth-of-interaction (DOI) determination, are MR compatible, and offer faster response and higher gain than other solid-state photosensors such as avalanche photodiodes. Here we present a novel detector...

Monolithic scintillator PET detectors with intrinsic depth-of-interaction correction

We developed positron emission tomography (PET) detectors based on monolithic scintillation crystals and position-sensitive light sensors. Intrinsic depth-of-interaction (DOI) correction is achieved by deriving the entry points of annihilation photons on the front surface of the crystal from the light sensor signals. Here we characterize the...

Signal to Noise Ratio of APD-Based Monolithic Scintillator Detectors for High Resolution PET

Using Cramer-Rao theory combined with Monte Carlo simulations for the optimization of monolithic scintillator PET detectors

Experimental characterization of monolithic-crystal small animal PET detectors read out by APD arrays