EMCCD Camera Research Articles

Low-coherence interferometry with polynomial interpolation on Compute Unified Device Architecture-enabled graphics processing units

An algorithm for interpolation of central fringe position in low-coherence interferometry measurements is presented. The algorithm is based on a polynomial curve fitting. Fast calculation of interpolation is possible due to the use of an NVIDIA Compute Unified Device Architecture (CUDA) technology, which allows independent analysis of different points of a high-resolution detector matrix on separate cores of a graphics processing unit (GPU). The dependency of the method’s accuracy on the spectral width of the light source is checked. The computation times on a GPU are compared with those achieved with a multicore central processing unit, showing nearly 30 times faster calculations when using CUDA technology. The algorithm accuracy is tested by measuring a flat glass surface with two different cameras—an ordinary CCD camera and a cooled EMCCD camera. Finally, the algorithm is applied to measurements of a populated optical fiber connector array prototyped using deep proton writing technology.

Performance of scientific cameras with different sensor types in measuring dynamic processes in fluorescence microscopy

The plethora of available scientific cameras of different types challenges the biologically oriented experimenter when picking the appropriate camera for his experiment. In this study, we chose to investigate camera performances in a typical nonsingle molecule situation in life sciences, that is, quantitative measurements of fluorescence intensity changes from video data with typically skewed intensity distributions. Here, intensity profile dynamics of pH-sensors upon triggered changes of pH-environments in living cells served as a model system. The following camera types were tested: sCMOS, CCD (scientific and nonscientific) and EM-CCD (back- and front-illuminated). We found that although the EM-CCD cameras achieved the best absolute spatial SNR (signal-to-noise ratio) values, the sCMOS was at least of equal performance when the spatial SNR was related to the effective dynamic range, and it was superior in terms of temporal SNR. In the measurements of triggered intensity changes, the sCMOS camera had the advantage that it used the smallest fraction of its dynamic range when depicting intensity changes, and thus featured the best SNR at full usage of its dynamic range.

MO‐D‐141‐07: X‐Ray Activated Gold Nanoparticles for Tumor‐Specific Molecular Imaging

Purpose: X‐ray radiography and computed tomography are commonly used anatomical imaging modalities still have significant shortcomings in sensitivity and specificity. Molecular imaging based on tumor‐specific nanoparticles that can probe biochemical processes in vivo can provide characterization and identification of benign and malignant lesions on the cellular level. In particular, radioluminescent nanoparticles (RLNPs) are the ideal platform for X‐ray‐mediated imaging and synergistic therapy during radiation treatment. These unique particles can emit visible light under X‐ray irradiation. However, existing RLNPs based on lanthanides may cause toxicity in vivo. Here we report new intriguing radioluminescent properties of a new type of nanoparticles made by arranging a small number of gold atoms. The objective of this work is to examine practical aspects of a new imaging modality: light emission and spectral emission characteristics. Methods: Bare gold nanoparticles (4 and 1.8 nm) and conjugated gold nanoparticles with size less than 2 nm (25 atoms size) were synthesized. Imaging was performed by irradiating the samples with X‐ray (30–80 kVp, 10–30 mA) while acquiring 10 s frames with an EMCCD camera (Princeton Instruments, 300–900 nm). The samples were further characterized by using a custom PMT‐based system. The spectral properties of the emission were measured under both optical and X‐ray excitation using a sensitive spectrometer. Results: It was found that tested gold nanoparticles had different responses to x‐ray excitation. Au25‐BSA is the most promising candidate for x‐ray luminescence imaging, with up to 4‐6‐fold increase in the optical signal compared to the controls. Conclusion: In this work, it was first time demonstrated the optical detection of small atom number gold nanoparticles excited by x‐ray source. Development of a new optical imaging probes will allow us to take advantage of the desirable features of optical molecular imaging and achieve substantially improved spatiotemporal resolution, sensitivity and specificity for tumor detection.

A direct gaseous ethanol imaging system for analysis of alcohol metabolism from exhaled breath

A non-invasive breath gaseous ethanol imaging system with an exhaled breath flow rate control has been developed. The system offers straight-forward, rapid, and painless sampling from patients, and can be applied to diagnose diseases. The system provides an image of ethanol concentration using chemiluminescence (CL) from an enzyme-immobilized support. The system measures ethanol concentrations as intensities of CL by luminol reaction induced by alcohol oxidase and horseradish peroxidase–luminol–hydrogen peroxide system. The spatio-temporal change in CL generates by ethanol in an exhaled breath is detected by an electron multiplier EM-CCD camera and analyzed. An ethanol skin patch test, a simple method of indicating aldehydehydrogenase 2 (ALDH2), is performed on healthy volunteers. Breath samples from volunteers with ALDH2(+) and ALDH2(−) are analyzed. The exhaled breath flow rate control unit can control and optimize the naturally unstable flow rate of human breath without a gas sampling bag. The coefficient of variance in the exhaled breath flow rate is estimated at 2.8% at a flow rate of 200mL/min. Exhaled gaseous ethanol obtained from volunteers is visualized and analyzed over a period of 300min following the oral administration of ethanol at 0.4g/kg body weight. A peak in the exhaled breath ethanol concentration appears at 30min for both ALDH2(+) and ALDH2(−) volunteers, the breath ethanol concentration then gradually decreases over the remainder of the 300min.

Real-Time Analysis and Visualization for Single-Molecule Based Super-Resolution Microscopy

Accurate multidimensional localization of isolated fluorescent emitters is a time consuming process in single-molecule based super-resolution microscopy. We demonstrate a functional method for real-time reconstruction with automatic feedback control, without compromising the localization accuracy. Compatible with high frame rates of EM-CCD cameras, it relies on a wavelet segmentation algorithm, together with a mix of CPU/GPU implementation. A combination with Gaussian fitting allows direct access to 3D localization. Automatic feedback control ensures optimal molecule density throughout the acquisition process. With this method, we significantly improve the efficiency and feasibility of localization-based super-resolution microscopy.

Cooperative Recruitment of Dynamin and BIN/Amphiphysin/Rvs (BAR) Domain-containing Proteins Leads to GTP-dependent Membrane Scission*

Dynamin mediates various membrane fission events, including the scission of clathrin-coated vesicles. Here, we provide direct evidence for cooperative membrane recruitment of dynamin with the BIN/amphiphysin/Rvs (BAR) proteins, endophilin and amphiphysin. Surprisingly, endophilin and amphiphysin recruitment to membranes was also dependent on binding to dynamin due to auto-inhibition of BAR-membrane interactions. Consistent with reciprocal recruitment in vitro, dynamin recruitment to the plasma membrane in cells was strongly reduced by concomitant depletion of endophilin and amphiphysin, and conversely, depletion of dynamin dramatically reduced the recruitment of endophilin. In addition, amphiphysin depletion was observed to severely inhibit clathrin-mediated endocytosis. Furthermore, GTP-dependent membrane scission by dynamin was dramatically elevated by BAR domain proteins. Thus, BAR domain proteins and dynamin act in synergy in membrane recruitment and GTP-dependent vesicle scission.

Calibration on the Spot of EMCCD Cameras for Super Resolution Microscopy

In single-molecule biophysics and super-resolution microscopy, fluorescent probes are routinely localized with nanometer precision in images taken, e.g., with an EMCCD camera. In such images, an isolated probe images as a diffraction-limited spot of light which was formed by a finite number of photons. The probe's coordinates are estimated from the recorded camera intensities in the spot, and the error on this estimate, the localization error, is given by a mathematical formula that depends on the number of photons in the spot. Translation of measured intensities to photon numbers requires a calibration of the camera for the specific setting with which it is used. Here we show how this can be done post festum from just a recorded image. We demonstrate this (i) theoretically, mathematically, (ii) by analyzing images recorded with an EMCCD camera, and (iii) by analyzing simulated EMCCD images for which we know the true values of parameters. In summary, our method of calibration-on-the-spot allows calibration of a camera with unknown settings from old images on file, with no other info needed. Consequently, calibration-on-the-spot also makes future camera calibrations before and after measurements unnecessary, because the calibration is encoded in recorded images during the measurement itself, and can at any later time be decoded with calibration-on-the-spot.

How can the Enhanced Sensitivity and Favourable Noise Characteristics Conferred by Electron Multiplication Improve Fluorescence-Guided Surgery?

Biomarkers are traceable substances that can be used to monitor pathological molecular processes and in particular to guide the resection of tumors. A biomarker that is currently being used clinically is the protoporphyrin IX (PpIX), which has been demonstrated to preferentially accumulate in high-grade glioma following administration of 5-aminolevulinic acid. In the case of high-grade glioma, PpIX accumulates in a sufficient manner that it can be seen through the naked eye when exposed to blue light. However, higher sensitivity is needed to detect PpIX in other types of brain tumors where PpIX levels are lower or to achieve more complete resections. Higher sensitivity has been achieved using a fiberoptics point-probe allowing surgeons to detect PpIX with an unparalleled sensitivity in vivo during gliomas surgeries. However, point-by-point detection disrupts the neurosurgical workflow and so less disrupting wide-field imaging methods with high sensitivity and rapid image acquisition are desirable.We investigate whether or not electron multiplication devices (EMCCD) can confer sensitivity and acquisition time advantages in fluorescence-guided neurosurgery when compared to scientific-grade charge-coupled devices (CCD). We present a demonstration of the sensitivity of PpIX detection that can be obtained with a new EMCCD camera that was developed by Nuvu Cameras. This device significantly reduces the noise generated during the read-out process (at least 10x) and presents a previously unreachable sensitivity in photon counting mode. Such major reduction in the noise threshold represents an opportunity to detect very faint levels of PpIX with smaller integration times than was previously achieved with CCDs. The goal of this study was to open the way to a less disruptive in vivo fluorescence detection technique to allow surgeon to perform more accurate resections on a more varied range of intracranial tumors

3D Structural Illumination Microscopy of the Skeletal Muscle Excitation-Contraction Coupling Macromolecular Complex

To study the structural organization of protein components associated with the membrane compartments involved in skeletal muscle excitation-contraction coupling, we stained enzymatically dissociated mouse FDB fibers with commercially available specific antibodies. Imaging was based on 3 dimensional structured illumination microscopy (3D-SIM, Zeiss Elyra system using a 63x/1.4 Plan-Apochromat lens and an EMCCD camera) or conventional confocal laser scanning microscopy for comparison (Zeiss LSM700). We investigated the localization pattern and distribution of RyR, Cav1.1 and of other protein components involved in excitation-contraction coupling. As expected, imaging of FBD fibers stained with anti -RyR Ab by conventional confocal microscopy revealed highly ordered band-line structures regularly distributed along the sarcomeres which strongly overlapped with Cav1.1. Analysis of the same FDB preparation at higher resolution (Dx-y 110-130 nm and Dz 280-340 nm) by 3D-SIM revealed a more distinct pattern of distribution. RyRs form 100 nm clusters, which are regularly separated and distributed along the longitudinal axis of the fiber. Anti-Cav 1.1 Ab stained clusters having a sarcomeric distribution co-localizing with RyRs. Cav 1.1 Ab also stained structures adjacent to but not overlapping with RyRs. These results suggest the power of the 3D-SIM approach to gain further insight into the structural organization of sarcotubular membranes in normal and diseased condition.

Accurate EMCCD Photoelectron Calibration for Single Molecule Imaging Techniques

EMCCDs are widely used in super-resolution and single molecule imaging methods. These techniques rely on photoelectron counts for particle detection and calculating localization precision of single molecules, making accurate calibration of EMCCD camera counts to photoelectrons unit necessary. Calibration methods used in literature include shot noise based calibration and manufacturer-provided formulas, but there is no general consensus and the accuracy of these methods has yet to be verified. First, we directly measure the light response of an EMCCD using a photon counting approach. We use a greatly attenuated laser to illuminate a few pixels on an EMCCD and compare the EMCCD counts to the readout of a photon counting photomultiplier tube placed in the same position. Second, we process uniformly illuminated EMCCD images to isolate shot noise as the dominant noise course to create an adjusted mean-variance method of calibrating EMCCDs. We verify this adjusted mean-variance method using our photon counting approach. Third, we compare these results to the theoretical values from the EMCCD calibration methods used in literature. To test our modified calibration method, we examine single molecule localization data and compared the data to existing models.

Single-Molecule Super-Resolution Microscopy at Video-Rate using Novel SCMOS-Specific Localization Algorithms

Single molecule localization based super resolution microscopy relies on precise and accurate localization of a large number of single molecules. However, the necessity of accumulating large numbers of localization estimates limits the time resolution to typically seconds to minutes.Two of the major limitations are the acquisition speed and the photon budget. Replacing EMCCD cameras which are usually implemented in such experiments with recently introduced SCMOS cameras results in a leap in both acquisition speed and effective quantum efficiency. However, the intrinsic pixel-dependent Gaussian noise of the SCMOS cameras introduces localization artifacts and greatly reduces the reliability of the results.Here, we present a set of specially designed statistics-based algorithms that allows for the first time to fully characterize an SCMOS camera and perform unbiased and precise localization analysis. Using this method we demonstrate Cramer-Rao lower bound-limited single molecule localization with an SCMOS camera. Combining this with a recently developed multi-emitter fitting algorithm and optimized imaging condition, we show that this technique shortens the typical acquisition time for fixed samples by up to two orders of magnitude without compromising the field of view. Furthermore, we demonstrate video-rate super-resolution microscopy of live cells by monitoring the transient clustering events of transferrin receptors with a reconstructed frame rate of 32 fps.The here presented method allows to replace EMCCD cameras with SCMOS technology and record faster and more precise super-resolution images without compromises.

Development of a novel multi-point plastic scintillation detector with a single optical transmission line for radiation dose measurement**US Patent pending.

The goal of this study was to develop a novel multi-point plastic scintillation detector (mPSD) capable of measuring the dose accurately at multiple positions simultaneously using a single optical transmission line. A 2-point mPSD used a band-pass approach that included splitters, color filters and an EMCCD camera. The 3-point mPSD was based on a new full-spectrum approach, in which a spectrograph was coupled to a CCD camera. Irradiations of the mPSDs and of an ion chamber were performed with a 6 MV photon beam at various depths and lateral positions in a water tank. For the 2-point mPSD, the average relative differences between mPSD and ion chamber measurements for the depth–dose were 2.4±1.6% and 1.3±0.8% for BCF-60 and BCF-12, respectively. For the 3-point mPSD, the average relative differences over all conditions were 2.3±1.1%, 1.6±0.4% and 0.32±0.19% for BCF-60, BCF-12 and BCF-10, respectively. This study demonstrates the practical feasibility of mPSDs. This type of detector could be very useful for pre-treatment quality assurance applications as well as an accurate tool for real-time in vivo dosimetry.

Fast Data Acquisition in Heavy Ion CT Using Intensifying Screen—EMCCD Camera System With Beam Intensity Monitor

We investigated the feasibility of fast data acquisition in heavy ion CT (IonCT) technique with an X-ray intensifying screen-charged coupled device (CCD) camera system. This technique is based on measuring the residual range distribution of heavy ions after passing through an object. We took a large number of images with a CCD camera for one projection by changing the range shifter (RS) thickness to obtain a characteristic curve similar to a Bragg curve and then to estimate the relative residual range. We used a high quality Electron Multiplying CCD (EMCCD) camera, which drastically reduced data acquisition time. We also used a parallel-plate ionization chamber upstream of an object to monitor the time variation in heavy ion beam intensity from a synchrotron accelerator and to perform beam intensity correction for all EMCCD images. Experiments were conducted using a broad beam of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> C, which was generated by spreading out the pencil beam accelerated up to 400 MeV/u by the Heavy Ion Medical Accelerator, in Chiba (HIMAC) at the National Institute of Radiological Sciences, with a scatterer. We demonstrated that a fast CT data acquisition, 14 min for 256 projections, is possible for an electron density phantom, consisting of six rods with a relative electron density resolution of 0.017, using the proposed technique with HIMAC.

Spectral Separation of Quantum Dots within Tissue Equivalent Phantom Using Linear Unmixing Methods in Multispectral Fluorescence Reflectance Imaging

Introduction Non-invasive Fluorescent Reflectance Imaging (FRI) is used for accessing physiological and molecular processes in biological media. The aim of this article is to separate the overlapping emission spectra of quantum dots within tissue-equivalent phantom using SVD, Jacobi SVD, and NMF methods in the FRI mode. Materials and Methods In this article, a tissue-like phantom and an optical setup in reflectance mode were developed. The algorithm of multispectral imaging method was then written in Matlab environment. The setup included the diode-pumped solid-state lasers at 479 nm, 533 nm, and 798 nm, achromatic telescopic, mirror, high pass and low pass filters, and EMCCD camera. The FRI images were acquired by a CCD camera using band pass filter centered at 600 nm and high pass max at 615 nm for the first region and high pass filter max at 810 nm for the second region. The SVD and Jacobi SVD algorithms were written in Matlab environment and compared with a Non-negative Matrix Factorization (NMF) and applied to the obtained images. Results PSNR, SNR, CNR of SVD, and NMF methods were obtained as 39 dB, 30.1 dB, and 0.7 dB, respectively. The results showed that the difference of Jacobi SVD PSNR with PSNR of NMF and modified NMF algorithm was significant (p<0.0001). The statistical results showed that the Jacobi SVD was more accurate than modified NMF. Conclusion In this study, the Jacobi SVD was introduced as a powerful method for obtaining the unmixed FRI images. An experimental evaluation of the algorithm will be done in the near future.

Multi-spectral video endoscopy system for the detection of cancerous tissue

Multi-spectral video endoscopy provides considerable potential for early stage cancer detection. Previous multi-spectral image acquisition systems were of limited use for endoscopy due to (i) the necessary spatial scanning of push-broom approaches or (ii) the impractical long switching times of liquid crystal tunable filters. Recent technological advances in the field of tuneable filters, in particular fast acousto-optical tunable filters (AOTF), make switching times below 1ms feasible. Thus, AOTFs represent a suitable technology for the acquisition of hyper-spectral image and multi-spectral video data with excellent spatial and temporal resolution. In this paper, we propose a hyper-spectral imaging endoscope using a fast AOTF synchronized with a highly sensitive EMCCD camera for the detection of cancerous tissue. The setup demonstrates that the acquisition of hyper-spectral image and multi-spectral video data is feasible and enables the augmentation of endoscopic videos with overlays indicating cancerous tissue regions.Using hyper-spectral measurements from biopsies acquired with the setup in a clinical environment it is shown that the spectral characteristic of cancerous regions is tissue dependent. Even a sophisticated classifier such as a Support Vector Machines (SVM) or a Mixture of Gaussian Classifier (MOGC) cannot generalize the discriminative information if the training set contains measurements from different tissue types (e.g. larynx vs. parotid). In contrast, a training data selection scheme that chooses similar training sets for a given test set achieves a better prediction accuracy using an approach based on a Quadratic Discriminant Classifier (QDC) with the important advantage of improved robustness and less liability to overtraining. Combined with an image registration removing motion-based acquisition artefacts, the spectral information allows the augmentation of the video stream with overlays indicating cancerous tissue regions.

Amino-terminal Cysteine Residues Differentially Influence RGS4 Protein Plasma Membrane Targeting, Intracellular Trafficking, and Function

Regulator of G-protein signaling (RGS) proteins are potent inhibitors of heterotrimeric G-protein signaling. RGS4 attenuates G-protein activity in several tissues. Previous work demonstrated that cysteine palmitoylation on residues in the amino-terminal (Cys-2 and Cys-12) and core domains (Cys-95) of RGS4 is important for protein stability, plasma membrane targeting, and GTPase activating function. To date Cys-2 has been the priority target for RGS4 regulation by palmitoylation based on its putative role in stabilizing the RGS4 protein. Here, we investigate differences in the contribution of Cys-2 and Cys-12 to the intracellular localization and function of RGS4. Inhibition of RGS4 palmitoylation with 2-bromopalmitate dramatically reduced its localization to the plasma membrane. Similarly, mutation of the RGS4 amphipathic helix (L23D) prevented membrane localization and its G(q) inhibitory function. Together, these data suggest that both RGS4 palmitoylation and the amphipathic helix domain are required for optimal plasma membrane targeting and function of RGS4. Mutation of Cys-12 decreased RGS4 membrane targeting to a similar extent as 2-bromopalmitate, resulting in complete loss of its G(q) inhibitory function. Mutation of Cys-2 did not impair plasma membrane targeting but did partially impair its function as a G(q) inhibitor. Comparison of the endosomal distribution pattern of wild type and mutant RGS4 proteins with TGN38 indicated that palmitoylation of these two cysteines contributes differentially to the intracellular trafficking of RGS4. These data show for the first time that Cys-2 and Cys-12 play markedly different roles in the regulation of RGS4 membrane localization, intracellular trafficking, and G(q) inhibitory function via mechanisms that are unrelated to RGS4 protein stabilization.

Osteopetrosis Mutation R444L Causes Endoplasmic Reticulum Retention and Misprocessing of Vacuolar H+-ATPase a3 Subunit

Osteopetrosis is a genetic bone disease characterized by increased bone density and fragility. The R444L missense mutation in the human V-ATPase a3 subunit (TCIRG1) is one of several known mutations in a3 and other proteins that can cause this disease. The autosomal recessive R444L mutation results in a particularly malignant form of infantile osteopetrosis that is lethal in infancy, or early childhood. We have studied this mutation using the pMSCV retroviral vector system to integrate the cDNA construct for green fluorescent protein (GFP)-fused a3(R445L) mutant protein into the RAW 264.7 mouse osteoclast differentiation model. In comparison with wild-type a3, the mutant glycoprotein localized to the ER instead of lysosomes and its oligosaccharide moiety was misprocessed, suggesting inability of the core-glycosylated glycoprotein to traffic to the Golgi. Reduced steady-state expression of the mutant protein, in comparison with wild type, suggested that the former was being degraded, likely through the endoplasmic reticulum-associated degradation pathway. In differentiated osteoclasts, a3(R445L) was found to degrade at an increased rate over the course of osteoclastogenesis. Limited proteolysis studies suggested that the R445L mutation alters mouse a3 protein conformation. Together, these data suggest that Arg-445 plays a role in protein folding, or stability, and that infantile malignant osteopetrosis caused by the R444L mutation in the human V-ATPase a3 subunit is another member of the growing class of protein folding diseases. This may have implications for early-intervention treatment, using protein rescue strategies.

Polarimetric coronagraphy of BD + 31°643

Context. The binary B5V star BD+31?643 exhibits a disk-like structure detected at optical wavelengths. Even though the feature is well centered on the star, it has been argued, based on Spitzer observations, that the feature is a filament not directly associated to the binary star. Aims. The purpose of the present paper is to investigate whether polarization imaging may provide evidence either for or against the disk hypothesis. In addition, we aim at clarifying whether there might be any additional close companion to the binary star. Methods. We used the coronagraph PolCor in its polarization mode in combination with an EMCCD camera allowing short unit exposure times. As a result of shift-and-add and frame selection, the spatial resolution is improved compared to traditional CCD imaging. In order to possibly reveal an additional stellar companion, we used high resolution spectroscopy in the optical and high spatial resolution imaging in the near-IR. Results. The disk/filament is much better seen in polarization; it is narrow and a line drawn along the ridge passes within a second of arc from the star. The degree of polarization is high (?50% after correction for the extended component of the reflection nebula) which means that the disk/filament must be approximately at the same distance as the star. Although we confirm that the feature is much brighter south-east than north-west of the star, the evidence that the feature is physically connected to the star is strengthened and suggests that we are witnessing the destruction process of an accretion disk. Our spectroscopy shows that at least one of the stars is a spectroscopic binary. We were, however, not able to spatially resolve any stellar component in addition to the two well separated stars.

Sci-Thur PM: YIS - 10: A new optically encoded single-fiber plastic scintillation detector for multi-point radiation dosimetry

To develop a new multi-point plastic scintillation detector (mPSD) that allows for simultaneous dose measurements at multiple points and uses a single optical guide. Two different prototypes were built. A two-point mPSD was built and light discrimination was based on the use of multiple color filters at the outputs of a network of optical fiber splitters. Light intensity was measured by an EMCCD camera. For the three-point mPSD, the light discrimination setup was replaced by a low-noise spectrometer. Depth-dose and profiles measurements were obtained on a 6 MV photon beam with the mPSDs inside a water phantom. An ion chamber was also used for comparison purpose. Finally, the three-point mPSD was tested under an Ir-192 high-dose-rate (HDR) brachytherapy dose delivery and compared to the treatment planning system. A good agreement was found between the measured and expected dose for both mPSDs. The average relative differences to the ion chamber measurement for the two-point mPSD were of (2.4 ± 1.6)% and (1.3 ± 0.8)%. For the three-point mPSD, these differences were of (2.3±1.1)%, (1.6±0.4)% and (0.32±0.19)%. The latter mPSD was shown very versatile, being able to measure dose from HDR brachytherapy with an average accuracy of (2.3±1.0)% per catheter. The practical feasibility of mPSDs using a single optical guide has been demonstrated under irradiation from a 6 MV photon beam and an Ir-192 HDR brachytherapy source. Their application for pre-treatment quality assurance and in vivo dosimetry will be various.

宇宙用高感度EM-CCDカメラ(放送技術・番組制作技術,および一般)

宇宙用高感度EM-CCDカメラ(放送技術・番組制作技術,および一般)