A5086051635- Medical Imaging Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Advanced Radiotherapy Techniques
- Advanced X-ray and CT Imaging
- Radiomics and Machine Learning in Medical Imaging
- Radiopharmaceutical Chemistry and Applications
- Advanced Optical Sensing Technologies
- Digital Radiography and Breast Imaging
- Particle Detector Development and Performance
- Advanced MRI Techniques and Applications
- Radiation Dose and Imaging
- Terahertz technology and applications
- Nanoplatforms for cancer theranostics
- Photodynamic Therapy Research Studies
- bioluminescence and chemiluminescence research
- Nuclear Physics and Applications
- Photoacoustic and Ultrasonic Imaging
- Radiation Therapy and Dosimetry
Stanford University
2020-2023
Harvard University
2018-2022
Massachusetts General Hospital
2018-2022
Gordon Center for Medical Imaging
2018-2021
Tehran University of Medical Sciences
2012-2019
Biophotonic imaging has revolutionized the operation room by providing surgeons intraoperative image-guidance to diagnose tumors more efficiently and resect with real-time image navigation. Among many medical modalities, near-infrared (NIR) light is ideal for image-guided surgery because it penetrates relatively deeply into living tissue, while nuclear provides quantitative unlimited depth information. It therefore develop an integrated system combining NIR fluorescence gamma-positron...
Objective. We are developing a portable, 'RF-penetrable', brain-dedicated time of flight (TOF)-PET insert (PETcoil) for simultaneous PET/MRI.Approach. In this paper, we evaluate the PET performance two fully assembled detector modules design outside MR room.Main results. The global coincidence resolution, 511 keV energy count rate, and temperature achieved over 2 h data collection were 242.2 ± 0.4 ps full width at half maximum (FWHM), 11.19% 0.02% FWHM, 22.0 0.1 kcps, 23.5 °C 0.3 °C,...
Small‐animal single‐photon emission computed tomography (SPECT) system plays an important role in the field of drug development and investigation potential drugs preclinical phase. The small‐animal High‐Resolution SPECT (HiReSPECT) scanner has been recently designed developed based on compact high‐resolution detectors. detectors are a parallel hole collimator, cesium iodide (sodium‐activated) pixelated crystal array two H8500 position‐sensitive photomultiplier tubes. In this system, full set...
With the advancement of Silicon Photomultiplier (SiPM) technology, these devices are becoming mainstream for use in high resolution PET detectors especially where compatibility with magnetic field is critical. Large-area SiPM arrays now widely used detector modules. The challenges emerged readout and timing circuitry by increase pixel density area. application-specific integrated circuits (ASICs) developed to standard anode/cathode outputs. detection principle, which produces dark current...
In this work, we present modeling and imaging performance of a dual panel limited-angle TOF-PET system for intraoperative surgical applications using GATE monte carlo toolkit. Several detector parameters such as pixel dimensions, timing resolution depth interaction along with tumor uptake ratio phantom dimension are varied. Ultimately properties to achieve specific task presented. To assess image resolution, employed Simple Back Projection (SBP) reconstruction due its fast speed compared...
Using an intra-operative gamma probe after periareolar or peritumoral injection of a radiotracer during surgery helps the surgeon to identify sentinel, first, nodal site regional metastasis in clinically node-negative patients. The pathological analysis this node can have important influence on treatment staging various cancers. This paper reports design and performance evaluation recently developed our department. detector unit system consists 8 mm diameter 10 thickness monolithic CsI(Tl)...
Multimodality imaging is a very promising field. The tremendous success of integrating positron emission tomography (PET) with computed (CT) has demonstrated the beneficial role it can play in clinical diagnosis. Compared to CT, MRI similar spatial resolution and offers better soft-tissue contrast, zero ionizing radiation exposure, simultaneous PET, functional information (fMRI) MR spectroscopy (MRS). Currently, permanently-integrated PET/MRI systems are available. However, high cost impedes...
Large area scintillation detectors applied in gamma cameras as well Single Photon Computed Tomography (SPECT) systems, have a major role in-vivo functional imaging. Most of the utilize hexagonal arrangement Photomultiplier Tubes (PMTs). In this work we large square-shaped PMTs with row/column and positioning. The Use square reduces dead zones detector surface. However, conventional center gravity method for positioning may not introduce an acceptable result. Hence, digital correlated signal...
We are exploring a scintillator-based PET detector with potential of high sensitivity, depth interaction (DOI) capability, and timing resolution, single-side readout. Our design combines two previous concepts: (1) multiple scintillator arrays stacked relative offset, yielding inherent DOI information, but good performance has not been demonstrated conventional light sharing (2) Single crystal array one-to-one coupling to the photodetector, showing superior compared its counterparts, lacks...
Simultaneous positron emission tomography / magnetic resonance imaging (PET/MRI) acquires fused anatomical and molecular information of diseases. However, this diagnostically attractive idea is highly technically challenging due to the mutual interference between PET MRI. Currently, clinical integrated PET/MRI systems are available, but only three support simultaneous two time-of-flight (ToF). For small brain structures, a brain-dedicated insert provides better spatial resolution sensitivity...
With the goal of developing a low-cost scintillator-based photon counting detector (PCD) with high dose efficiency suitable for CT, light transport characteristics in LYSO:Ce detectors containing laser induced optical barriers (LIOB) are simulated. Light confinement and collection efficiencies (LCE) studied variety barrier patterns properties (refractive index (RI) barrier/crystal interface roughness). Up to 80% is achievable simple pixel pattern one wall separating each coupled one-to-one...
To cost-effectively satisfy the high spatial resolution, sensitivity, and SNR needs for cardiac SPECT imaging that has not been met with conventional gamma camera, we are developing Dynamic Cardiac (DC-SPECT) diagnostic theranostics applications featuring: static body-contouring geometry large detector coverage (~225 deg), number of views using 80 modules each a dedicated loft-hole collimator, laser-processed CsI:Tl converging pixels to avoid depth interaction (DOI) blurring. The DC-SPECT...
We have used a subpicosecond laser with an output trigger synched to 4-GHz oscilloscope sampling at 25 GSa/s characterize the temporally resolved response of large area picosecond photodetector (LAPPD) single photons/photoelectrons. The LAPPD is (20 cm ×20 cm) photosensor nanosecond-width time arising from its underlying multichannel plate photomultiplier tube (MCP-PMT) structure. optical filters attenuate pulse intensity single-photon level. pulses are nearly identical in shape,...
Intraoperative Gamma Probe (IPG) remains the current gold standard modality for sentinel lymph node identification and tumor removal in cancer patients. However, even alongside optical dyes they do not meet with <5% false negative rates (FNR) requirement, a key metric suggested by American Society of Clinical Oncology (ASCO). We are aiming to reduce FNR using time flight (TOF) PET detector technology limited angle geometry system only two buckets coincidence, where one small-area is placed...
In this work we present a Positron Emission Tomography (PET) detector block, which can be used in different scanner geometries. The block uses 12×12 Silicon Photomultiplier (SiPM) pixels with the overall dimension of 50×50 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . SiPM technology has widely PET detectors, particularly presence magnetic field. large number per unit area, requires channel reduction technique to avoid readout...
PET imaging is playing an important role in the field of molecular regarding its high sensitivity detection radiotracers. Hence, development dedicated preclinical scanners with better performance parameters utilizing state-of-the-art technology has ongoing trend. We recently developed a prototype scanner based on pixelated lutetium-yttrium oxyorthosilicate (LYSO) crystals and Silicon Photomultiplier (SiPM) arrays. In this paper, we report system design properties together...
Accurate identification of sentinel lymph nodes (SNL) and complete tumor removal in cancer patients is critical importance leads to improved patient recovery survival. Gamma probes along with near infrared (NIR) are the gold standard SNL but have failed reduce false negative rates (FNR) desirable 5% value. By developing a high-resolution Positron Emission Tomography (PET) detector atop coincidence partially populated ring placed underneath bed <; 250 ps timing resolution, we aiming FNR...
We are presenting a novel design of highperformance brain dedicated PET scanner which focuses on optimizing imaging performance in the whole brain, as well head and neck, through simultaneous high resolution sensitivity. This is realized using sensitivity-optimized composed an elliptical cylinder that follows shape human head, together with added front back panels for increased coverage. System simulations 15 mm LYSO crystals show 23% sensitivity cerebral cortex region 16% field view (FOV)...