Application of cadmium sulfide photoresistor and open-source software for X-ray detection in mammography.

This study evaluates the feasibility of a radiation dosimeter that can monitor radiation exposure in real time based on the electro optical modulation of a liquid crystal (LC) cell and the photoconductor cadmium sulfide (CdS). Cadmium sulfide (CdS) is often used in photosensors because of its high reproducibility and sensitivity to light and radiation. As basic research, the electro optical features of a LC cell and a novel CdS photosensor were analyzed from the viewpoint of fabricating a radiation dosimeter. Based on the results, the feasibility of such a detection device was studied by analyzing the efficiency of its electro optical light modulation. The measurement results suggested that the detection system had high resolution and very good reproducibility, with CdS showing excellent X-ray detection efficiency. The results suggest that noise reduction can be achieved by incorporating an LC, given its static electric features. The results of this study could help realize real-time portable radiation dosimeter systems based on optical modulation and using a CdS photosensor.

Recently, various semiconductor compounds as radiation detection material have been researched for a diagnostic x-ray detector application. In this paper, we have fabricated the CdS detecton sensor that has good photosensitivity and high x-ray absorption efficiency among other semiconductor compounds, and evaluated the application feasibility by investigating the detection properties about energy range of diagnostic x-ray generator. We have fabricated the line voltage selector(LCV) for a signal acquisition and quantities of CdS sensor, and designed the voltage detection circuit and rectifying circuit. Also, we have used a relative relation algorithm according to x-ray exposure condition, and fabricated the interface board with DAC controller. Performance evaluation was investigated by data processing using ANOVA program from voltage profile characteristics according to resistive change obtained by a tube voltage, tube current, and exposure time that is a exposure condition of x-ray generator. From experimental results, an error rates were reduced according to increasing of a tube voltage and tube current, and a good properties of 6%(at 90 kVp) and 0.4%(at 320 mA) ere showed. and coefficient of determination was 0.98 with relative relation of 1:1. The error rate according to x-ray exposure time showed exponential reduction because of delayed response velocity of CdS material, and the error rate has 2.3% at 320 msec. Finally, the error rate according to x-ray dose is below 10%, and a high relative relation was showed with coefficient of determination of 0.9898.

Sens-A-Ray characteristics with variations in beam quality

Gravimetric method is usually used to evaluate air-dry density, which is governing physical or mechanical properties of wood. Although it had high evaluation accuracy, the method is time consuming process. Thus, this study was conducted to estimate air-dry density of wood with high accuracy by using polychromatic X-ray and digital detector as alternative of gravimetric method. To quantify polychromatic X-ray projection for evaluating air-dry density, Lambert-Beer’s law with the integral value of probability function was used. The integral value was used as weighting factor in the law, and it was determined by conducting simple test at various penetration depths and tube voltage. Mass attenuation coefficient (MAC) of wood also calculated by investigating polychromatic X-ray projection according to species, penetration depth and tube voltage. The species had not an effect on change of MAC. Finally, an air-dry density of wood was estimated by applying the integral value, MAC and Lambert-Beer’s law to polychromatic X-ray projection. As an example, the relation of the integral value (α) according to penetration depth (t, cm) at tube voltage of 35 kV was α=–0.00091t×0.0184 while the regression of the MAC (μ, cm2/g) was μ=0.5414exp(–0.0734t). When calculation of root mean squared error (RMSE) was performed to check the estimation accuracy, RMSE at 35, 45 and 55 kV was 0.010, 0.013 and 0.009 g/cm3, respectively. However, partial RMSE in relation to air-dry density was varied according to tube voltage. The partial RMSE below air-dry density of 0.41 g/cm3 was 0.008 g/cm3 when tube voltage of 35 kV was used. Meanwhile, the partial RMSE above air-dry density of 0.41 g/cm3 decreased as tube voltage increased. It was conclude that the accuracy of estimation with polychromatic X-ray and digital detector was quite high if the integral value and MAC of wood were determined precisely or a condition of examination was chosen properly. It was seemed that the estimation of air-dry density by using polychromatic X-ray system can supplant the gravimetric method.

This study aims to investigate and optimize the effect of different exposure parameters on the reduction of noise and radiation dose and to find the optimal balance among tube voltage, tube current, and exposure time for the latest-generation cone-beam computed tomography system (CBCT) at Advanced Medical and Dental Institute, Universiti Sains Malaysia, using the dose area product (DAP) meter. The DAP meter was attached to the X-ray detector of the CBCT device to cover the entire irradiated area and then connected to a Raysafe electrometer. The DAP meter was scanned with the following exposure parameter: constant tube voltage of 70 kV with a varying tube current ranging from 5 mA – 16 mA and then at a constant tube current of 10mA and a varying tube voltage ranging from 60 kV – 80 kV. For each scanning protocol, the noise was determined. At constant tube voltage and varying tube current, the noise level ranged from 41.99 – 82.16, while at constant tube current and varying tube voltage, the noise level ranged from 50.66 – 60.76 with equal exposure time. A 0.09% increase in noise was observed when the tube voltage was varied. Therefore, low noise protocols should consist of a reduction in the tube current setting rather than a reduction in peak voltage (kVp), as this would result in a smaller level of noise and consequently less quality degradation in the image.

Primary Ciliary Dyskinesia (PCD) is a rare genetic disorder characterized by alterations in motile cilia function. The diagnosis of PCD is challenging due to the lack of standardized methods in clinical practice. High-speed video microscopy analysis (HSVA) directly evaluates ciliary beat frequency (CBF) in PCD. Recently, open-source ciliary analysis software applications have shown promise in measuring CBF accurately. However, there is limited knowledge about the performance of different software applications, creating a gap in understanding their comparative effectiveness in measuring CBF in PCD. We compared two open-source software applications, CiliarMove (v219) and Cilialyzer (v1.2.1-b3098cb), against the manual count method. We used high-speed videos of nasal ciliary brush samples from PCD RSPH4A-positive (PCD (RSPH4A)) patients and healthy controls. All three methods showed lower median CBF values for patients with PCD (RSPH4A) than in healthy controls. CiliarMove and Cilialyzer identified lower CBF in patients with PCD (RSPH4A), similarly to the manual count. Cilialyzer, CiliarMove, and manual count methods demonstrated statistical significance (p-value < 0.0001) in the difference of median CBF values between patients with PCD (RSPH4A) and healthy controls. Correlation coefficients between the manual count values against both software methods demonstrated positive linear relationships. These findings support the utility of open-source software-based analysis tools. Further studies are needed to validate these findings with other genetic variants and identify the optimal software for accurate CBF measurement in patients with PCD.

Background:Increasing tube voltage which balanced with decreasing tube current and exposure time, it can decrease patient dose. base on optimization principle of radiation protection and radiation safety, it must be some effort in order to make patient dose minimally as it needed to get diagnostic information. The purpose of this research are to find out radiation dose on kV which usually use in Radiology Departement, radiation dose on kV with higher than usual, and two find out radiation dose acceptance on both of technique was appropriate with reference dose that set by BAPETEN.Methods : Type of this research was quantitative research with experimental approach. This research took place in laboratory 2 JTRR Semarang. This research had been done by illumination chest phantom which completed with TLD (Thermoluminisense Dosimeter) placed correct on central point on MSP (Mid Sagital Plane) as level as angulus inferior scapulae. Analyze data had been shown used tables by average accounting, compare between acceptance radiation dose on kV which usually use in Radiology Departement and on kV with higher than usual, and compare result radiation dose with reference dose that set by BAPETEN.Results :The result of this research shown that there was difference acceptance radiation dose entrance skin on chest examination in postero-anterion projection on tube voltage which usually use in Radiology Departement, radiation dose on tube voltage with higher than usual. The average value of radiation dose on kV usually use in Radiology Departement was 0,059 mGy, while on tube voltage with higher than usual the average value of radiation dose was 0.020 mGy. The result of testing that used kV with higher than usual, acceptance radiation dose entrance skin which accepted was lower than on tube voltage usually use in Radiology Departement. The result of radiation dose on tube voltage usually use in Radiology Departement although used tube voltage with higher than usual, its value were lower than reference dose, it was 0,4 mGy that set by BAPETEN.Conclusion : Based on these results, using a higher tube voltage than is usually very useful to reduce the radiation dose received by the patient, then this technique should be applied in Radiology for the examination of the thorax with the PA that has a projection plane X-ray modality with high capability above 100 kV.

This paper aims to optimize the parameters of a portable device that combines X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis techniques. By using the same X-ray source and detector, the device enables the simultaneous acquisition of two-dimensional XRD and XRF information from a sample with the advantage of high analysis efficiency and consistency in the measurement points. The equipment and slit materials are discussed, including the selection of the X-ray source (Moxtek MAGNUM) and the detector (Andor CCD camera). We also explore two different slit designs (the bottom-hole and side-hole) and optimize their dimensions using rectangular holes instead of inclined trapezoidal holes. Considering the fluorescence X-rays of the filters in the X-ray tube spectra, a theoretical formula is derived for rapid and accurate calculation. The calculated results are compared with the experimental results of Al and Ni filters, demonstrating good agreement across various tube voltages and filter thicknesses. Furthermore, an XRD/XRF comprehensive analysis platform is established. The effects of tube voltage, tube current, exposure time, and pixel-binning on the single-pixel events of the CCD camera are investigated and can be used to guide the selection of appropriate device parameters. The effects of the frame and tube voltage on the XRD/XRF analysis efficiency are examined for several sample materials, including Al, α-Fe, Zn, and ZrO2(Y2O3).

Photon-counting x-ray detectors may enable single-exposure dual-energy (DE) x-rayangiography. The purpose of this paper is to experimentally optimize the energy thresholds and tube voltage for single-exposure DE x-rayangiography. We optimized single-exposure DE x-ray angiography using the iodine signal-difference-to-noise ratio (SDNR) per root patient air kerma (κ) as a figureof merit. We measured the iodine SDNR by imaging an iodine stepwedge immersed in a water tank with a depth of 30cm in the direction of x-ray propagation. The stepwedge was imaged using tube voltages ranging from 90 to 150kV and a cadmium telluride (CdTe) x-ray detector with two energy bins and analog charge summing for charge sharing suppression. The energy threshold that separates the two energy bins was varied from approximately 35keV to approximately 75% of the maximum energy of the x-ray beam. Curve fitting was used to determine the threshold that maximized . The effect of scatter was determined from measurements of the scatter-to-primary ratios (SPRs) of the low-energy and high-energy images and a semi-empirical model of the relationship between SDNR and SPR. Using the optimal parameters, we imaged a phantom with vessel-simulating structures and backgroundclutter. The optimal energy thresholds increased monotonically from ∼50 to ∼85keV over the range of tube voltages considered. For tube voltages greater than 90kV, the optimal energy thresholds consistently allocated approximately two thirds of all detected primary photons to the low energy bin; this ratio was preserved without scatter. Consistent with prior modeling studies, increased monotonically with tube voltage from 90 to 150kV; at 150kV was approximately 38% higher than that at 90kV for an iodine area density of ∼50mg/cm2 . Scatter reduced SDNR by approximately 25% for SPRs of ∼1 and 0.4 in low-energy and high-energy images, respectively. Achieving optimal image quality in single-exposure DE angiography with photon-counting x-ray detectors will require high tube voltages (i.e.,>130kV) and, for thick patients, energy thresholds that allocate approximately two thirds of all primary photons to the low-energy image. Future work will compare the image quality of singe-exposure photon-counting and kV-switching approaches to DE x-rayangiography.

Hopes and Hypes for Artificial Intelligence in Colorectal Cancer Screening

Domain generalization in deep learning based mass detection in mammography: A large-scale multi-center study

The goal of this study was to assess the influence of the target-filter combination and the tube voltage on lesion detection and average glandular dose (AGD) in digital mammography using a flat-panel X-ray detector based on amorphous silicon technology. For the assessment of image quality images of the ACR mammographic accreditation phantom were obtained. Increasing peak voltage by 2 kVp decreases breast dose by 7% for the same target-filter combination. Changing the target-filter combination from Mo-Mo to Mo-Rh decreases AGD by approximately 10% and changing from Mo-Mo to Rh-Rh decreases the AGD by approximately 30% at the same peak voltage values. In the peak voltage range between 25 and 35 kVp there was no difference in lesion detectability for different tube voltages at the same detector dose between Mo-Mo and Mo-Rh.

To compare radiation exposure associated with daily practice cardiovascular (CV) examinations performed on two different multidetector computed tomography (MDCT) scanners, a conventional 64-MDCT and a third-generation dual-source (DS) MDCT. In this retrospective study, 1458 patients who underwent CV examinations between January 2017 and August 2018 were enrolled. A single-source 64-MDCT (Lightspeed VCT, GE) scan was performed in 705 patients from January to August 2017 (207 coronary examinations and 498 vascular examinations) and 753 patients underwent third-generation 192 × 2-DSCT (Somatom FORCE, Siemens) scan from January to August 2018 (302 coronary examinations and 451 vascular examinations). Volume CT dose index (CTDIvol), dose length product (DLP), effective dose (ED), tube voltage (TV) and exposure time (ET), pitch factor (PF) were registered for each patient. Student's t test was used to compare mean values between each corresponding group of MDCT and DSCT. In coronary examinations with DSCT, CTDIvol was 24.4% lower (23.1mGy vs 30.6mGy, p < 0.0001) and DLP and ED reductions were 35.6% than with MDCT (465.0mGy*cm vs 732.3mGy*cm and 6.5mSv and 10.3mSv; vs p < 0.0001). Concerning scan parameters, kVp and ET reductions were 12.7% and 69.4%, respectively (p < 0.0001); PF increase was 73.8% (p < 0.0001). In all vascular studies, DSCT, compared with MDCT, permitted to reduce CTDIvol from 43.5 to 70.6%; DLP and ED reductions were from 50.3 to 73.1%; kVp and ET decreases were from 10.7 to 32.5% and from 26.3 to 68.7%. PF increase was from 16.7 to 58.1% (all differences with p < 0.0001). In daily practice, CV examinations CTDI, DLP, ED, ET and TV were lower and PF was higher with 192 × 2-DSCT compared to 64-MDCT.

In this paper, we present a detailed study on the effects of x-ray exposure on data corruption in commercially available NOR and NAND flash memory devices during x-ray inspection with a high-resolution Phoenix Nanomex system from GE. We investigated role of the x-ray tube voltage, tube current, device orientation, x-ray filters and photon energy. We explored the low exposure regime in detail when the first byte errors start occurring and also determined the absorbed dose for 100% byte errors. No data corruption was observed after the normal 2D x-ray inspection and CT scans of the NOR and NAND flash memory devices under study. However, increase in the tube voltage, tube current and/or the x-ray beam size resulted in byte errors which increased exponentially with the exposure time. The byte error rate was found to be much more sensitive to the tube voltage than the tube current. It was also affected by the device orientation with respect to the x-ray beam. The NAND flash memories were found to be more susceptible to data corruption from x-ray exposure than the NOR devices examined in this work. Some NOR devices were irradiated with the monochromatic x-rays from the CHESS synchrotron facility at Cornell University. Of all the photon energies used in this study, 12 keV x-ray irradiation resulted in the highest byte error rate. In this paper, we thus present a direct proof that it is the low-energy photon absorption that plays a major role in introducing bit errors in flash memories. Commonly available low-energy x-ray filters such as Cu and Al foils were found to be effective in preventing data corruption in such devices for long exposure time. Use of lower tube voltage, lower tube current, smaller x-ray spot size, short exposure time and low-energy x-ray filters, is recommended to prevent data corruption during 2D and 3D x-ray inspection of flash memory devices and other semiconductor devices in general.

A study of the projection of root canals of natural teeth on dental roentgenograms was carried out as a sequel to an earlier phantom study. The material consisted of extracted teeth and teeth in situ in jaw preparations. The same radiation source and focus-film distance were used throughout, but the exposure times and tube voltages were varied. The roentgenographic images of the root canals were analysed densitometrically and compared with measurements of the actual object dimensions. The root were sectioned at the level studied and their cross sections were traced and measured with the aid of a profile projector. There was good agreement between the true breadth of the canal and that projected on the film. The maximum contrast in the image of the canal and the densitometrically measured difference in substance, expressed in metal equivalents, were proportional to the depth of the canal in the direction of radiation. The breadth of the canal in the plane of the film was the same regardless of whether the tube voltage was 50, 60 or 90 kV. On the other hand, the tube voltage affected the photographic density differences between the canal and the dentine walls. Changing the voltage from 50 to 60 kV did not affect the results, but there was a highly significant difference between 90 and 50 or 60 kV. The clinical significance of tube voltage and exposure time is discussed.