flat panel detector

BACKGROUND: The development of a new imaging modality, such as 4D dynamic contrast-enhanced dedicated breast CT (4D DCE-bCT), requires optimization of the acquisition technique, particularly within the 2D contrast-enhanced imaging modality. Given the extensive parameter space, cascade-systems analysis is commonly used for such optimization. PURPOSE: To implement and validate a parallel-cascaded model for bCT, focusing on optimizing and characterizing system performance in the projection domain to enhance the quality of input data for image reconstruction...

Newer cone-beam computed tomography (CBCT) imaging systems offer reconstruction algorithms including metal artifact reduction (MAR) and extended field-of-view (eFoV) techniques to improve image quality. In this study a new CBCT imager, the new Varian HyperSight CBCT, is compared to fan-beam CT and two CBCT imagers installed in a ring-gantry and C-arm linear accelerator, respectively.

Approach: The image quality was assessed for HyperSight CBCT which uses new hardware, including a large-size flat panel detector, and improved image reconstruction algorithms...

BACKGROUND AND PURPOSE: Flat-panel detector computed tomography (FDCT) immediately after mechanical thrombectomy (MT) can detect complications including early hemorrhagic transformation and subarachnoid hyperdensities (SH). The clinical significance of SH in patients undergoing MT remains unclear. MATERIALS AND METHODS: We studied 223 patients who underwent MT for anterior circulation stroke, had FDCT performed immediately after the procedure, and had follow-up imaging within 24 hours...

A multiple sub-pupil ultra-spectral imaging system designed with a single spectrometer and detector can simultaneously detect multiple-channel spectra with ultra-high spectral resolution. However, due to using a prism in the system's front end, the nonlinear dispersion introduces spectral line tilt in the imaging spectra. This phenomenon can lead to bias in the final spectral data. To eliminate this issue, we propose a new design by introducing a second prism to correct this spectral tilt in the system. The angle of spectral line tilt generated by the nonlinear dispersion of the first prism is derived...

BACKGROUND: X-ray multi-contrast imaging with gratings provides a practical method to detect differential phase and dark-field contrast images in addition to the x-ray absorption image traditionally obtained in laboratory or hospital environments. Systems have been developed for preclinical applications in areas including breast imaging, lung imaging, rheumatoid arthritis hand imaging and kidney stone imaging. PURPOSE: Prevailing x-ray interferometers for multi-contrast imaging include Talbot-Lau interferometers and universal moiré effect-based phase-grating interferometers...

PURPOSE: Flat-panel detector computed tomography (FDCT) is increasingly used in (neuro)interventional angiography suites. This study aimed to compare FDCT perfusion (FDCTP) with conventional multidetector computed tomography perfusion (MDCTP) in patients with acute ischemic stroke. METHODS: In this study, 19 patients with large vessel occlusion in the anterior circulation who had undergone mechanical thrombectomy, baseline MDCTP and pre-interventional FDCTP were included...

PURPOSE: Total knee arthroplasty (TKA), which has medial pivot and mobile-bearing mechanisms, has been developed and clinically used. However, the in vivo dynamic kinematics of the mobile medial pivot-type TKA (MMPTKA) is unclear. This study analysed the in vivo kinematics of MMPTKA in weight-bearing and nonweight-bearing conditions. METHODS: The study included 10 knees that underwent primary TKA using MMPTKA. After TKA, lateral view radiographs of the knee in full extension, 90° of flexion and passive full flexion were taken under general anaesthesia in the nonweight-bearing condition...

The development of lead halide perovskite X-ray detectors has promising applications in medical imaging and security inspection but is hindered by poor long-term stability and drift of the dark current and photocurrent. Herein, we design a (Cs0.05 MA0.65 FA0.3 )PbI3 -(Cs0.1 MA1.3 FA0.6 )AgBiI6 double-layer perovskite film to assemble a self-powered flat-panel X-ray detector. The demonstrated X-ray detector achieves an outstanding self-powered sensitivity of 80 μC Gyair -1 cm-2 under a 0 V bias. More importantly, owing to the inhibition of the phase transition process and ion migration of (Cs0...

Selenium (Se), the world's oldest optoelectronic material, has been widely applied in various optoelectronic devices such as commercial X-ray flat-panel detectors and photovoltaics. However, despite the rare and widely-dispersed nature of Se element, a sustainable recycling of Se and other valuable materials from spent Se-based devices has not been developed so far. Here a sustainable strategy is reported that makes use of the significantly higher vapor pressure of volatile Se compared to other functional layers to recycle all of them from end-of-life Se-based devices through a closed-space evaporation process, utilizing Se photovoltaic devices as a case study...

BACKGROUND AND PURPOSE: Dose calculation on cone-beam computed tomography (CBCT) images has been less accurate than on computed tomography (CT) images due to lower image quality and discrepancies in CT numbers for CBCT. As increasing interest arises in offline and online re-planning, dose calculation accuracy was evaluated for a novel CBCT imager integrated into a ring gantry treatment machine. MATERIALS AND METHODS: The new CBCT system allowed fast image acquisition (5...

Cone beam computed tomography (CBCT) is known to suffer from strong scatter and cone beam artifacts. The purpose of this study is to develop and characterize a rapidly scanning carbon nanotube (CNT) field emission x-ray source array to enable a multisource CBCT (ms-CBCT) image acquisition scheme which has been demonstrated to overcome these limitations. A CNT x-ray source array with eight evenly spaced focal spots was designed and fabricated for a medium field of view ms-CBCT for maxillofacial imaging. An external multisource collimator was used to confine the radiation from each focal spot to a narrow cone angle...

Halide perovskites have emerged as promising candidates in X-ray detection due to their strong X-ray absorption and excellent optoelectronic properties. The development of sensitive and stable flat-panel X-ray detectors with high resolution is crucial for practical applications. In this paper, we introduce a novel flat-panel X-ray detector that integrates quasi-two-dimensional (2D) Ruddlesden-Popper (RP) perovskite with a pixeled thin film transistor (TFT) backplane. We incorporate 2,5-dibromopyrimidine (DBPM) as an additive to passivate the Lewis acid defects in the quasi-2D RP perovskite...

Introduction X-rays are widely used in medicine for diagnosis and treatment. Such beneficial uses may cause potentially hazardous situations for patients and workers in the cardiac catheterization laboratory. The present study aims to estimate the radiation dose scattered in different parts of the catheterization units and doses absorbed by workers in this unit, and patients who underwent cardiac catheterization procedures to evaluate all changes in hematological parameters and damaged cells (the cells that contain a number of chromosomal aberrations) after exposure to radiation at Azadi Teaching Hospital in the Duhok City of Iraq...

Dual-layer detectors provide a low-cost solution to improved material decomposition and lesion differentiation in X-ray imaging, while eliminating motion artifacts from multiple exposures. Most designs utilize two indirect detectors with scintillators designed for low-energy and higher-energy detection and separated by a copper filter to harden the beam for high energy detection. To improve the performance of the bottom detector and lower dose requirements, we have previously proposed an alloyed amorphous selenium photodetector to achieve improved resolution and absorption at green wavelengths, better suited to high-performance scintillators such as CsI:Tl...

BACKGROUND: In spite of the tremendous potential of game-changing biological image- and/or biologically guided radiation therapy (RT) and adaptive radiation therapy for cancer treatment, existing limited strategies for integrating molecular imaging and/or biological information with RT have impeded the translation of preclinical research findings to clinical applications. Additionally, there is an urgent need for a highly integrated small-animal radiation therapy (SART) platform that can seamlessly combine therapeutic and diagnostic capabilities to comprehensively enhance RT for cancer treatment...

Organic semiconducting materials are promising for the fabrication of flexible ionizing radiation detectors for imaging because of their tissue equivalence, simple large-scale processing, and mass production. However, it is challenging to achieve high-sensitivity detection for organic direct detectors prepared by low-cost solution processing because of the compromise between thickness and carrier transport. In this study, high-performance organic direct X-ray detectors were fabricated by building a micrometer-thick bulk heterojunction (BHJ) using poly(3-hexylthiophene-2,5-diyl) (P3HT):(6,6)-phenyl c71 butyric acid methyl ester...

OBJECTIVES: To compare the radiation dose and image quality between flat panel detector (FPD) and traditional image intensifier (II) C-arms at their lowest radiation settings. METHODS: In a ureteroscopy simulation using a cadaver model, the radiation exposure was compared between FPD and II at 4 pulses-per-second (pps) using both low dose and automatic exposure control (AEC) settings. Additionally, the lowest dose settings for each machine were compared (4 pps with low dose in the FPD and 1 pps with low dose in the II)...

A semi-analytical solution to the unified Boltzmann equation is constructed to exactly describe the scatter distribution on a flat-panel detector for high-quality conebeam CT (CBCT) imaging. The solver consists of three parts, including the phase space distribution estimator, the effective source constructor and the detector signal extractor. Instead of the tedious Monte Carlo solution, the derived Boltzmann equation solver achieves ultrafast computational capability for scatter signal estimation by combining direct analytical derivation and time-efficient one-dimensional numerical integration over the trajectory along each momentum of the photon phase space distribution...

PURPOSE: In recent years, there has been a growing movement in Western countries toward the abolition of gonadal protection during radiography. The reasons for this recommendation are that there are few reports of increased risk of genetic effects, that the ovarian dose is not due to direct X-rays but due to internally scattered X-rays that cannot be shielded, and that the presence of gonadal protection may adversely affect the automatic exposure control mechanism and may mask important findings...

BACKGROUND: MR-LINAC systems have been increasingly utilized for real-time imaging in adaptive treatments worldwide. Challenges in MR representation of air cavities and subsequent estimation of electron density maps impede planning efficiency and may lead to dose calculation uncertainties. PURPOSE: To demonstrate the generation of accurate electron density maps using the primary MV beam with a flat-panel imager. METHODS: The ViewRay MRIdian MR-LINAC system was modeled digitally for Monte Carlo simulations...