Patient-specific fetal radiation dosimetry for pregnant patients undergoing abdominal and pelvic CT imaging

Background: Accurate estimation of fetal radiation dose is crucial for risk-benefit analysis of radiological imaging, while the radiation dosimetry studies based on individual pregnant patient are highly desired. Purpose: To use Monte Carlo calculations for estimation of fetal radiation dose from abdominal and pelvic computed tomography (CT) examinations for a population of patients with a range of variations in patients’ anatomy, abdominal circumference, gestational age (GA), fetal depth (FD), and fetal development. Methods: Forty-four patient-specific pregnant female models were constructed based on CT imaging data of pregnant patients, with gestational ages ranging from 8 to 35 weeks. The simulation of abdominal and pelvic helical CT examinations was performed on three validated commercial scanner systems to calculate organ-level fetal radiation dose. Results: The absorbed radiation dose to the fetus ranged between 0.97 and 2.24 mGy, with an average of 1.63 ± 0.33 mGy. The CTDIvol-normalized fetal dose ranged between 0.56 and 1.30, with an average of 0.94 ± 0.25. The normalized fetal organ dose showed significant correlations with gestational age, maternal abdominal circumference (MAC), and fetal depth. The use of ATCM technique increased the fetal radiation dose in some patients. Conclusion: A technique enabling the calculation of organ-level radiation dose to the fetus was developed from models of actual anatomy representing a range of gestational age, maternal size, and fetal position. The developed maternal and fetal models provide a basis for reliable and accurate radiation dose estimation to fetal organs.</p

Lattice Boltzmann Phase Field Simulations of Droplet Slicing

ACKNOWLEDGEMENT This research was sponsored by Shanghai Sailing Program (No. 20YF1416000) and SUES Distinguished Overseas Professor Program.Peer reviewedPostprin

A Novel Antidiabetic Food Produced via Solid-State Fermentation of Tartary Buckwheat by L. plantarum TK9 and L. paracasei TK1501

Dijabetes je kronična metabolička bolest koju karakteriziraju povećana razina šećera u krvi te niz mogućih komplikacija vezanih s tim, što znatno umanjuje kakvoću života pacijenta. U ovom smo istraživanju proizveli funkcionalnu hranu za dijabetičare od heljde fermentirane s pomoću sojeva Lactobacillus plantarum TK9 i L. paracasei TK1501. Rezultati ortogonalnog eksperimentalnog plana pokazuju da su tri glavna faktora koja su najviše utjecala na rast L. plantarum TK9 i L. paracasei TK1501 na čvrstoj podlozi bili: omjer supstrata i vode>veličina inokuluma>vrijeme fermentacije. Pri optimalnim uvjetima fermentacije heljde, a to su: omjer supstrata i vode 1:1,5, vrijeme fermentacije od 24 h i inokulum od 10^7 CFU/g, dobiveno je (2,3±0,7)·10^9 probiotika s pomoću soja L. plantarum TK9 i (3,3±0,4)·10^9 CFU/g probiotika s pomoću soja L. paracasei TK1501. Ispitani su hranjiva vrijednost te antioksidativni i antidijabetički učinci etanolskog ekstrakta fermentirane heljde. Najjača inhibicija α-glukozidaze s IC50=0,51 mg/mL postignuta je s heljdom fermentiranom s pomoću L. plantarum TK9, dok je heljda fermentirana s pomoću L. paracasei TK1501 najviše inhibirala dipeptidil peptidazu IV (DPP-IV), s IC50=2,47 mg/mL. Stoga je zaključeno da se pomoću oba soja može proizvesti hrana za dijabetičare koja smanjuje razinu šećera u krvi.Diabetes is a chronic metabolic disease characterized by hyperglycaemia and a number of potential complications that significantly reduce the patient’s quality of life. In this study, we produced an antidiabetic functional food from Tartary buckwheat fermented by Lactoba cillus plantarum TK9 and L. paracasei TK1501. The results of an orthogonal experimental design indicated that the three factors with the largest effects on the growth of L. plantarum TK9 and L. paracasei TK1501 in solid-state fermentation (SSF) were in the order: water ratio>inoculum size>time of fermentation. Under the optimal fermentation conditions comprising a 1:1.5 water ratio, 24 h of SSF and a 107 CFU/g inoculum, the Tartary buckwheat fermented by L. plantarum TK9 and L. paracasei TK1501 yielded viable probiotic counts of (2.3±0.7)·10^9 and (3.3±0.4)·10^9 CFU/g, respectively. The nutritional potential, as well as antioxidant and antidiabetic properties of ethanolic extracts from fermented Tartary buckwheat were investigated. The highest α-glucosidase inhibitory activity, with an IC50 of 0.51 mg/mL, was present in Tartary buckwheat fermented by L. plantarum TK9. However, Tartary buckwheat fermented by L. paracasei TK1501 had the highest dipeptidyl peptidase IV (DPP-IV) inhibition, with an IC50 of 2.47 mg/mL. Therefore, fermentation by both L. plantarum TK9 and L. paracasei TK1501 has the potential to yield a product that can help regulate the levels of blood glucose as part of a diabetic diet

The Design Of Intelligent Filter For EEG

EEG data processing method is usually digital filter designed by the traditional method. Its disadvantage is the transition zone is wide and the filtering effect is poor. Using an improved particle swarm optimization algorithm on IIR digital filters design, the performances of filters designed by various methods are compared and analyzed. Experiments illustrate particle swarm optimization algorithm is effective in IIR filter design and its performance is promising

The Design Of Intelligent Filter For EEG

EEG data processing method is usually digital filter designed by the traditional method. Its disadvantage is the transition zone is wide and the filtering effect is poor. Using an improved particle swarm optimization algorithm on IIR digital filters design, the performances of filters designed by various methods are compared and analyzed. Experiments illustrate particle swarm optimization algorithm is effective in IIR filter design and its performance is promising

Guided block matching and 4-D transform domain filter projection denoising method for dynamic PET image reconstruction

Abstract Purpose Dynamic PET is an essential tool in oncology due to its ability to visualize and quantify radiotracer uptake, which has the potential to improve imaging quality. However, image noise caused by a low photon count in dynamic PET is more significant than in static PET. This study aims to develop a novel denoising method, namely the Guided Block Matching and 4-D Transform Domain Filter (GBM4D) projection, to enhance dynamic PET image reconstruction. Methods The sinogram was first transformed using the Anscombe method, then denoised using a combination of hard thresholding and Wiener filtering. Each denoising step involved guided block matching and grouping, collaborative filtering, and weighted averaging. The guided block matching was performed on accumulated PET sinograms to prevent mismatching due to low photon counts. The performance of the proposed denoising method (GBM4D) was compared to other methods such as wavelet, total variation, non-local means, and BM3D using computer simulations on the Shepp–Logan and digital brain phantoms. The denoising methods were also applied to real patient data for evaluation. Results In all phantom studies, GBM4D outperformed other denoising methods in all time frames based on the structural similarity and peak signal-to-noise ratio. Moreover, GBM4D yielded the lowest root mean square error in the time-activity curve of all tissues and produced the highest image quality when applied to real patient data. Conclusion GBM4D demonstrates excellent denoising and edge-preserving capabilities, as validated through qualitative and quantitative assessments of both temporal and spatial denoising performance

Potential of Fluid Dynamic Bowtie Filter for Dose Reduction and Image Quality Improvement of Cone-Beam CT

Reducing radiation dose to patients without compromising imaging quality has been an important issue in the medical use of X-ray computed tomography (CT). In this study, based on the conceptual designs of different types of attenuation filters, the radiation doses to patients who undergo a typical head, thorax and abdomen scan using a cone-beam CT with different scanning protocols were simulated using the Monte Carlo method, and the isotropy of the noise power spectrum (NPS) of the reconstructed images was also calculated. Compared to the scanning protocol without attenuation and tube current modulation (TCM), the results showed that the fluid dynamic bowtie filter (FDB) combined with the TCM technique reduced the average organ dose by 70%, 34% and 60% for a typical head, thorax and abdomen scan, respectively, and the NPS isotropy of the reconstructed images was also significantly improved. Compared to most currently used static bowtie filters, the FDB has a higher potential to reduce the dose for patients undergoing CT scans. Further efforts are warranted to make the FDB technique clinically useful

Decision Analysis of a Reinforcement Scheme for In-Service Prestressed Concrete Box Girder Bridges Based on AHP and Evaluation of the Reinforcement Effect

Prestressed concrete girder bridges are widely used worldwide due to their mature construction technology, economical cost, and low maintenance. After a certain number of years of service, prestressed concrete girders inevitably suffer from deterioration of their material properties, cracking, and reduced load-carrying capacity due to the natural environment and long-term vehicle loading. When the performance of a bridge declines to the point that it cannot meet the requirements of normal use, reinforcement and maintenance are required. In this study, a 5 × 45 m prestressed concrete continuous box girder bridge that has been in service for 25 years is taken as an example, and the causes of crack development and deterioration of the technical condition of the bridge are analyzed. Based on an analysis of the causes, reinforcement schemes for overall replacement of the girder and adding bridge piers are proposed. According to a comparison of the advantages and disadvantages, a decision analysis of the reinforcement scheme is carried out via the analytic hierarchy process (AHP). The vector weights of the two schemes were found to be 0.4288 and 0.5712, respectively, indicating that adding bridge piers is more advantageous than overall replacement of the girder. Thus, a scheme of adding five piers was adopted to reinforce the bridge. A load test was then performed after the reinforcement, and both the test deflection and strain calibration coefficients were found to be less than 1, indicating that the force state of the added piers and bearings was better than the theoretical calculations. The present study shows that the reinforcement scheme of adding piers can achieve the design goal. The working status of the box girder was significantly improved, the crack development of box girder was suppressed, and the service life of the bridge was prolonged