Background
Reducing Magnetic resonance imaging (MRI) scan time has been an important issue for clinical applications. In order to reduce MRI scan time, imaging acceleration was made possible by ...undersampling k‐space data. This is achieved by leveraging additional spatial information from multiple, independent receiver coils, thereby reducing the number of sampled k‐space lines.
Purpose
The aim of this study is to develop a deep‐learning method for parallel imaging with a reduced number of auto‐calibration signals (ACS) lines in noisy environments.
Methods
A cycle interpolator network is developed for robust reconstruction of parallel MRI with a small number of ACS lines in noisy environments. The network estimates missing (unsampled) lines of each coil data, and these estimated missing lines are then utilized to re‐estimate the sampled k‐space lines. In addition, a slice aware reconstruction technique is developed for noise‐robust reconstruction while reducing the number of ACS lines. We conducted an evaluation study using retrospectively subsampled data obtained from three healthy volunteers at 3T MRI, involving three different slice thicknesses (1.5, 3.0, and 4.5 mm) and three different image contrasts (T1w, T2w, and FLAIR).
Results
Despite the challenges posed by substantial noise in cases with a limited number of ACS lines and thinner slices, the slice aware cycle interpolator network reconstructs the enhanced parallel images. It outperforms RAKI, effectively eliminating aliasing artifacts. Moreover, the proposed network outperforms GRAPPA and demonstrates the ability to successfully reconstruct brain images even under severe noisy conditions.
Conclusions
The slice aware cycle interpolator network has the potential to improve reconstruction accuracy for a reduced number of ACS lines in noisy environments.
Raki is a traditional Turkish drink. It is obtained by distillation process after suma (alcoholic water) obtained from raisins is sweetened with anise (pinpinella anisum). The quality of raki depends ...on the quality of the grapes used in the production process and technological differences. In this study, in order to ensure consumer food safety, 10 different raki samples in Turkey were thawed by microwave cracking system, and their trace element content was examined. Differential pulse polarography (DPP), which has high selectivity and sensitivity, was used for the measurements. Appropriate measurement conditions were determined for each element. Validation of the method was done with a known sample. The detection limit of the method was determined as 0.1 μgg-1. The amounts of Fe, Cu, Pb, Cd, Cr, As, Ni, Zn, Se elements in the raki samples were determined as approximately 2-80 μgg-1.
Purpose
To evaluate an iterative learning approach for enhanced performance of robust artificial‐neural‐networks for k‐space interpolation (RAKI), when only a limited amount of training data ...(auto‐calibration signals ACS) are available for accelerated standard 2D imaging.
Methods
In a first step, the RAKI model was tailored for the case of limited training data amount. In the iterative learning approach (termed iterative RAKI iRAKI), the tailored RAKI model is initially trained using original and augmented ACS obtained from a linear parallel imaging reconstruction. Subsequently, the RAKI convolution filters are refined iteratively using original and augmented ACS extracted from the previous RAKI reconstruction. Evaluation was carried out on 200 retrospectively undersampled in vivo datasets from the fastMRI neuro database with different contrast settings.
Results
For limited training data (18 and 22 ACS lines for R = 4 and R = 5, respectively), iRAKI outperforms standard RAKI by reducing residual artifacts and yields better noise suppression when compared to standard parallel imaging, underlined by quantitative reconstruction quality metrics. Additionally, iRAKI shows better performance than both GRAPPA and standard RAKI in case of pre‐scan calibration with varying contrast between training‐ and undersampled data.
Conclusion
RAKI benefits from the iterative learning approach, which preserves the noise suppression feature, but requires less original training data for the accurate reconstruction of standard 2D images thereby improving net acceleration.
Purpose
Simultaneous multi‐slice acquisitions are essential for modern neuroimaging research, enabling high temporal resolution functional and high‐resolution q‐space sampling diffusion acquisitions. ...Recently, deep learning reconstruction techniques have been introduced for unaliasing these accelerated acquisitions, and robust artificial‐neural‐networks for k‐space interpolation (RAKI) have shown promising capabilities. This study systematically examines the impacts of hyperparameter selections for RAKI networks, and introduces a novel technique for training data generation which is analogous to the split‐slice formalism used in slice‐GRAPPA.
Methods
RAKI networks were developed with variable hyperparameters and with and without split‐slice training data generation. Each network was trained and applied to five different datasets including acquisitions harmonized with Human Connectome Project lifespan protocol. Unaliasing performance was assessed through L1 errors computed between unaliased and calibration frequency‐space data.
Results
Split‐slice training significantly improved network performance in nearly all hyperparameter configurations. Best unaliasing results were achieved with three layer RAKI networks using at least 64 convolutional filters with receptive fields of 7 voxels, 128 single‐voxel filters in the penultimate RAKI layer, batch normalization, and no training dropout with the split‐slice augmented training dataset. Networks trained without the split‐slice technique showed symptoms of network over‐fitting.
Conclusions
Split‐slice training for simultaneous multi‐slice RAKI networks positively impacts network performance. Hyperparameter tuning of such reconstruction networks can lead to further improvements in unaliasing performance.
•A study about authentication of a traditional aniseed flavoured spirit, raki.•Mid-IR spectroscopy is succesfully used in detection of methanol adulteration of raki.•Quantification of adulteration of ...raki is also achieved with the same technique in combination with chemometrics.
Consumption of traditional aniseed alcoholic beverage, raki, adulterated with methanol results in deaths, therefore, its detection is an important issue. In this study, mid-infrared spectra of pure and methanol adulterated (0.5–10% (vol/vol)) raki samples were collected with an attenuated total reflectance attachment of a Fourier-transform infrared spectrometer. Principal component analysis was used to discriminate pure and adulterated raki samples, then, a partial least square model was constructed to determine the adulterant methanol content in raki using mid-IR spectral data. A minimum threshold level of 0.5% methanol in raki samples was successfully detected. A good prediction model for determination of methanol adulteration ratio in raki samples was also constructed (R2=0.98 and RPD=8.35).
Mid-infrared (IR) spectroscopy, which is a rapid and relatively small amount of waste producing technique, was used to predict several quality parameters of two types of alcoholic beverages, wine and ...raki. Mid-infrared spectra of red, rose and white wines and a traditional aniseed alcoholic beverage, raki were collected and relations were established between measured chemical parameters (pH, brix, total phenol content, anthocyanin content, titratable acidity, sugar content, electrical conductivity and some colour parameters) of these beverages and their infrared spectra using chemometric techniques. Partial least square regression provided excellent prediction of total phenol (
R
2
= 0.97) and anthocyanin contents (
R
2
= 0.98) of wine samples and a good prediction of pH (
R
2
= 0.9), brix (
R
2
= 0.92) and colour intensity (
R
2
= 0.93) values were obtained. Brix, total phenol and sugar content of raki samples were also estimated very successfully (
R
2
= 0.99) for raki and good prediction was obtained with pH value. Mid-IR spectroscopy in combination with chemometrics could be a promising technique for determination of several quality parameters of alcoholic beverages simultaneously and rapidly.
Illegal alcohol beverages known as bogma raki in our country are consumed widely in our region. The studies investigating the relationship between alcohol consumption and hearing ability report ...different results. In this study, we aimed to investigate the toxic effects of bogma raki that contains neurotoxic substances on cochlea by electron microscopy. To the best of our knowledge, this study is the first in the literature. A total of 48 Wistar male albino rats (aged 12–16 weeks and weighing 200–240 g) were used in the study. The rats were divided into 4 groups with 12 animals in each group. The groups include control, bogma raki, walnut, and walnut + bogma raki groups. Bogma raki (30% v/v, 9.2 ml kg−1 day−1) is added to drinking water of rats in bogma raki group (n = 12) for 4 weeks. Walnut group rats (n = 12) are fed with standard rat food and walnut without limitation (10 g kg−1 day−1). Bogma raki + walnut group rats (n = 12) are fed with standard rat food and walnut and bogma raki is added to drinking water. The cochleas were dissected and removed en bloc and examined by electron microscopy. Perineuronal oedema around neurons of spiral ganglion and hairy cells of organ of Corti were present in the bogma raki group, walnut group and bogma raki + walnut group under electron microscopic examination. Comparing these three groups, there were no differences in the ultrastructural pathological changes. In the ultrastructural examination of the myelinated axons forming cochlear nerve, no ultrastructural pathology was detected in all the groups.
Abstract Objective and aim : Alcohol-related hepatotoxicity is not only caused by excessive alcohol consumption but also caused and even accelerated by hepatotoxic ingredients other than ethanol. ...Concentrations of hepatotoxic substances might be significantly high, particularly in illegally produced home-made alcohols. In this study we aim to analyze the hepatotoxic effects of a home-made alcohol traditionally called “bogma raki” in Turkey. Materials and method Fifty Wistar albino male rats were used. Five groups were randomly formed with ten animals in each. Besides laboratory diets, groups were fed as follows: Group 1 (control group) distilled water; Group 2 bogma raki with distilled water (%44 (v/v), 9.2 ml/kg/day); Group 3 bogma raki with distilled water (%44 (v/v), 9.2 ml/kg/day)+walnut (10 g/kg/day); Group 4 whisky with distilled water (%40 (v/v), 9.2 ml/kg/day); Group 5 distilled water + walnut (10 g/kg/day), for 28 days. The toxicological analysis of The spirits were analyzed using Hewlett-Packard (Palo Alto, CA) GC/MS system with HP 6890 gas chromatograph, an HP 5972 mass selective detector (MSD) and an HP 6890 automatic liquid sampler GC/MS; the pressure of the carrier gas helium was 6.0 bar and the split value with a ratio of 1:100. The injection unit temperature set to 250 °C and MS quadrupole temperature set to 280 °C. The MS quadrupole detector ionization energy set to 70 eV. The initial column temperature was 60 °C (for 4 min) programmed by 6 °C/min to final temperature 160 °C and kept for 8 min at 160 °C. Utilized whisky and bogma raki samples were analyzed for the amounts of trans -anethole, ethanol, methanol, 1-propanolol, butanol, 2-butanol, 2-methyl-1-propanolol (isobutanol) and 3-methylbutanol (isoamyl alcohol). Histopathological changes in liver tissues were graded as follows; normal = 0 (<10%), mild = 1 (10%–40%), moderate = 2 (40%–70%), severe = 3 (above 70%). Results Chemical composition of illegally produced raki sample (%v/v) was as follows: trans -anethole %1.93, ethanol %95.70, 2-methyl-1-propanolol (isobutanol) %0.19, asetic acid %0.25, 3-methylbutanol (isoamyl alcohol) %0.77, and others %1.16. Chemical composition of commercial whisky sample (%v/v) was as follows: ethanol %97.72, 2-methyl-1-propanolol (isobutanol) %0.57, asetic acid %0.23, 3-methylbutanol (isoamyl alcohol) %1.28, and others %0.2. No traces of trans -anethole were detected in whisky. Normal liver morphology was recorded in control and walnut groups. However, bogma raki caused significant congestion and inflammatory cell infiltration compared to control and walnut group. On the other hand, whisky administration caused mild degeneration including inflammation in a limited area. Conclusion Obtained findings suggest that trans -anethole containing alcoholic beverages are more hepatotoxic compared to commercial alcoholic beverages.
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