Gm Tissue Research Articles

A low-profile dual-band millimeter wave patch antenna for high-speed wearable and biomedical applications

This paper presents a low-profile, dual-band patch antenna designed for the mmWave frequency range. The antenna, fed by a microstrip line, is fabricated on a thin, flexible substrate (Rogers 3003) with dimensions of 12 × 3 × 0.25 mm³. The radiating patch includes two circular slots, enabling dual-band operation at 28 GHz and 38 GHz. Key performance metrics, including realized gain, efficiency, and radiation patterns, are analyzed across these frequency bands, with measured results compared to simulations performed using CST Microwave Studio. Furthermore, the antenna's parameters are evaluated in a bent configuration, demonstrating its suitability for wearable applications. The study also assesses the antenna's impact on human tissues, calculating average SAR values of 0.914 W/Kg and 1.140 W/Kg at 28 GHz, and 0.720 W/Kg and 1.360 W/Kg at 38 GHz, for 1/10 gm tissue. Furthermore, the link margin is calculated to verify effective wireless communication over distances up to 80 m. This antenna effectively covers key millimeter-wave frequency bands, making it ideal for high-speed 5 G and biomedical applications.

Effect of chronic alcohol consumption on brain structure in males with alcohol use disorder without a familiar history of alcoholism

Structural brain damages caused by chronic alcohol consumption have been extensively reported. However, the neuroimaging findings in people with alcohol use disorder (AUD) are relatively inconsistent. This inconsistency may be due to the influence of different variables that are not always considered, such as the presence of a family history of alcoholism (FHA). The main aim of this research is to study the gray (GM) and white matter (WM) volumes in male participants with AUD without FHA compared to healthy control males (HC) without FHA. For this study, we included 19 participants with AUD without FHA and 18 HC males without FHA. T1-weighted images were acquired with a General Electric Signa Exite 1.5 T scanner. GM and WM tissues were calculated using Diffeomorphic Anatomical Registration Through Exponentiated Lie algebra (DARTEL). All analyses were controlled for age and total brain volume. The statistical threshold was calculated with AlphaSim and further adjusted to account for the non-isotropic smoothness of structural images, according to Hayasaka et al. (2004). The obtained main results showed that, relative to the HC group, the participants with AUD without FHA had significantly lower GM in several brain structures, reflecting relatively purely the effects of chronic alcohol intake on brain volume. GM structure integrity is relevant for the efficient functioning of low and high-order cognitive processes used in everyday life, and its damage seems to be related to the severity/intensity/chronicity of the AUD. As such, it becomes relevant to assess and follow brain structural changes through the dependence course.

A new 3D MRI segmentation method based on Generative Adversarial Network and Atrous Convolution

Background and aimAlthough many algorithms have been proposed to segment brain structures in MRI scans, comparison of different algorithms in the same data set is rarely done. Many methods still run on privately held data and include comparisons with previous versions. The purpose of this study is to introduce a new Generative Adversarial Network (GAN) based segmentation architecture. Brain tissues on 3D-MRI scans with T1w modality were segmented into three (GM, WM, CSF) and eight (CGM, BG, WM, WMH, CF, VE, CE ve BS) parts. MethodsThe proposed approach (Vol2SegGAN) consists of two parts: preprocessing and segmentation. The preprocessing includes extraction of the brain region, editing of labels in the datasets, MNI152 registration, clipping/sampling. The segmentation part is carried out by the collaboration of a generator (includes ACFP and PAM modules) and a discriminator (distinguishes real/fake) architectures. ConclusionsIn the three part segmentation process, the proposed method showed the best segmentation success in CSF (Dice = 0.739, VS = 0.967), GM (Dice = 0.878, HD = 2.378) and WM (HD = 2.105) tissues, and the second best segmentation success in WM (Dice = 0.793, VS = 0.972) tissue according to Dice and VS metrics. Similarly, in the segmentation of eight parts, it is seen that it has the best success according to VS and HD metrics and the second best according to Dice metric. Vol2SegGAN, which has fewer parameters (6,883 mil.) than existing architectures, has an average of 11–12 s (CPU) or 0–1 s (GPU) to segment a sample 3D-MRI. Implementation codes of the proposed architecture are available on the github page11(https://github.com/GaffariCelik/Vol2SegGAN).

Whole brain and deep gray matter structure segmentation: Quantitative comparison between MPRAGE and MP2RAGE sequences.

T1-weighted MRI images are commonly used for volumetric assessment of brain structures. Magnetization prepared 2 rapid gradient echo (MP2RAGE) sequence offers superior gray (GM) and white matter (WM) contrast. This study aimed to quantitatively assess the agreement of whole brain tissue and deep GM (DGM) volumes obtained from MP2RAGE compared to the widely used MP-RAGE sequence. Twenty-nine healthy participants were included in this study. All subjects underwent a 3T MRI scan acquiring high-resolution 3D MP-RAGE and MP2RAGE images. Twelve participants were re-scanned after one year. The whole brain, as well as DGM segmentation, was performed using CAT12, volBrain, and FSL-FAST automatic segmentation tools based on the acquired images. Finally, contrast-to-noise ratio between WM and GM (CNRWG), the agreement between the obtained tissue volumes, as well as scan-rescan variability of both sequences were explored. Significantly higher CNRWG was detected in MP2RAGE vs. MP-RAGE (Mean ± SD = 0.97 ± 0.04 vs. 0.8 ± 0.1 respectively; p<0.0001). Significantly higher total brain GM, and lower cerebrospinal fluid‏ volumes were obtained from MP2RAGE vs. MP-RAGE based on all segmentation methods (p<0.05 in all cases). Whole-brain voxel-wise comparisons revealed higher GM tissue probability in the thalamus, putamen, caudate, lingual gyrus, and precentral gyrus based on MP2RAGE compared with MP-RAGE. Moreover, significantly higher WM probability was observed in the cerebellum, corpus callosum, and frontal-and-temporal regions in MP2RAGE vs. MP-RAGE. Finally, MP2RAGE showed a higher mean percentage of change in total brain GM compared to MP-RAGE. On the other hand, MP-RAGE demonstrated a higher overtime percentage of change in WM and DGM volumes compared to MP2RAGE. Due to its higher CNR, MP2RAGE resulted in reproducible brain tissue segmentation, and thus is a recommended method for volumetric imaging biomarkers for the monitoring of neurological diseases.

Design of Circularly Polarized Triple-Band Wearable Textile Antenna with Safe Low SAR for Human Health

In this manuscript, an antenna on textile (jeans) substrate is presented for the WLAN, C band and X/Ku band. This is a wearable textile antenna, which was formed on jeans fabric substrate to reduce surface-wave losses. The proposed antenna design consists of a patch and a defected ground. To energize the wearable textile antenna, a microstrip line feed technique is used in the design. The impedance band width of 23.37% (3.4–4.3 GHz), 56.48% (4.7–8.4 GHz) and 31.14% (10.3–14.1 GHz) frequency bands are observed, respectively. The axial ratio bandwidth (ARBW) of 10.10% (4.7–5.2 GHz), 4.95% (5.9–6.2 GHz) and 10.44% (11.8–13.1 GHz) frequency bands are observed, respectively. A peak gain of 4.85 dBi is analyzed at 4.1-GHz frequency during the measurement. The SAR value was calculated to observe the radiation effect and it was found that its utmost SAR value is 1.8418 W/kg and 1.919 W/kg at 5.2/5.5-GHz frequencies, which is less than 2 W/kg of 10 gm tissue. The parametric study is performed for the validation of the proper functioning of the antenna.

Determination the Ischemic Stroke of Brain MRI Based On Apparent Diffusion Coefficient (ADC) with b Value Variation

The Research to Determination the Ischemic Stroke of Brain MRI Based on Apparent Diffusion Coefficient (ADC) with b Value variations. The purposes of this study were to find b valuevariations of Diffusion Weighted Image (DWI), determining the optimum b value to find out the Contrast to Noise Ratio (CNR) ischemic stroke lesion in DWI image, and To determine the Diffusion Coefficient range obtained from the ADC (Apparent Diffusion Coefficient) value between old ischemic stroke and new ischemic stroke. In this research, used are 0, 500 and 1000. The result obtained b value influenceon the quality of DWI were analyzed in 30 patients suspected with old ischemic stroke and new ischemic stroke. Data analysis was done quantitatively with the Region Of Interest (ROI) directly on computer MRI image planes and were conducted statistical tests Signal to Noise Ratio (SNR) and Contrast to Noise Ratio (CNR). The highest Signal to Noise Ratio (SNR) found in b 0, while the highest Contrast to Noise Ratio (CNR) on the b 1000 s/mm 2. The statistics test show that significant SNR value of the Lesion, around the lesion, Liquor, WM, GM tissue is about 0,000 (p<0,05), while for the Contrast to Noise Ratio (CNR) of the lesion and around the lesion tissue is about 0,000 (p<0,05). This results showed that b value variation have a difference at lesion, around the lesion, Liquor, WM, GM tissue for MRI imaging quality. SNR and CNR are important aspect on imaging optimalization process to give the diagnose information. In this research, the diffusion coefficient value in new ischemic stroke is < 1 × 10−3, whereas the old ischemic stroke is > 1 × 10−3, the results showed that15 patients have new ischemic stroke and 15 patients have old ischemic stroke.

Agrobacterium-Mediated Transformation of Russian Commercial Plum cv. "Startovaya" (Prunus domestica L.) With Virus-Derived Hairpin RNA Construct Confers Durable Resistance to PPV Infection in Mature Plants.

In modern horticulture Plum pox virus (PPV) imposes serious threats to commercial plantations of a wide range of fruit species belonging to genera Prunus. Given the lack of natural genetic resources, which display reliable resistance to PPV infection, there has been considerable interest in using genetic engineering methods for targeted genome modification of stone fruit trees to control Sharka disease caused by PPV. Among the many virus defense mechanisms, RNA interference is shown to be the most promising transgenic disease-control strategy in plant biotechnology. The present study describes the production of transgenic PPV resistant European plum “Startovaya” (P. domestica L.) through the Agrobacterium-mediated transformation of in vitro leaf explants. Due to organogenesis from leaves, the established protocol allows the genetic engineering of the plum genome without losing clonal fidelity of original cultivar. Seven independent transgenic plum lines containing the self-complementary fragments of PPV-CP gene sequence separated by a PDK intron were generated using hpt as a selective gene and uidA as a reporter gene. The transformation was verified through the histochemical staining for β-glucuronidase activity, PCR amplification of appropriate vector products from isolated genomic DNA and Southern blot analysis of hairpin PPV-CP gene fragments. To clarify the virus resistance, plum buds infected by PPV-M strain were grafted onto 1-year-old transgenic plants, which further were grown into mature trees in the greenhouse. As evaluated by RT-PCR, DAS-ELISA, Western blot, ImmunoStrip test, and visual observations, GM plum trees remained uninfected over 9 years. Infected branches that developed from grafted buds displayed obvious symptoms of Sharka disease over the years and maintained the high level of virus accumulation, whereby host transgenic trees had been constantly challenged with the pathogen. Since the virus was unable to spread to transgenic tissues, the stable expression of PPV-derived gene construct encoding intron-spliced hairpin RNAs provided a highly effective protection of plum trees against permanent viral infection. At the same time, this observation indicates the lack of the systemic spread of resistance from GM tissues to an infected plum graft even after years of joint growth.

NEUROCHEMICAL, HEMATOLOGICAL AND BEHAVIORAL ALTERATIONS RELATED TO ESZOPICLONE ADMINISTRATION IN RATS

This study aimed to shed light on the effect of eszopiclone (ESZ) administration once daily for 30 consecutive days at night time on some neurochemical, behavioral and hematological criteria. A total of 27 male Wister albino rats were assigned to one of three drug treatment groups, vehicle, Eszopiclone (3mg/kg) and (6mg/kg). After 30 days of Eszopiclone administration, the neurochemical analysis revealed a significant reduction in serotonin and glutamate (306.44 ng/ml, 4.33 nmol /μl, respectively) in 6mg/kg treated animals, furthermore dopamine levels were significantly higher in rats treated with Eszopiclone (3mg/kg or 6mg/kg) in compare to control group. Reduced glutathione, superoxide dismutase and catalase levels revealed a significant decrease (0.15 μmol /gm tissue, 25.24 μmol /gm tissue, 1.93 Unit/gmtissue, respectively), while the malondialdehyde levels (15.79 nmol /gm tissue) demonstrated a significant increase in animals treated with 6 mg of ezopiclone. Behavioral assessment was carried out 3 times throughout the study (once/2 weeks) by video recording. It was recorded in 5 tests, including open field, the hole-board, inclined plain, grip and tail suspension tests. There were no changes between the rats in 3 mg/kg of ezopiclone and those in the control group. The rats in 6 mg/kg of ezopiclone showed less response in all behavioral observations, with significant decreases in inclined plain angle (23.35), exploratory time (17 second) and exploratory frequency (2 frequencies) in compare to other groups. The results support the concept that the administration of eszpiclone more than 3 mg/kg may lead to the behavioral changes. There were no serious adverse events regarding hematological indices. It is concluded that eszopiclone administration causes an imbalance between different neurotransmitters in the cerebrum. A marked decrease in antioxidant scavenging capacity with a behavioral alteration in 6mg/kg treated animals. The maximum safe dose of eszopiclone was 3mg/kg and more than this dose could lead to a deleterious reactions as evidenced in this study.

Improvement of CSF, WM and GM Tissue Segmentation by Hybrid Fuzzy — Possibilistic Clustering Model based on Genetic Optimization Case Study on Brain Tissues of Patients with Alzheimer’s Disease

Brain tissue segmentation is one of the most important parts of clinical diagnostic tools. Fuzzy C-mean (FCM) is one of the most popular clustering based segmentation methods. However FCM does not robust against noise and artifacts such as partial volume effect (PVE) and inhomogeneity. In this paper, a new approach for robust brain tissue segmentation is described. The proposed method quantifies the volumes of white matter (WM), gray matter (GM) and cerebrospinal fluid(CSF) tissues using hybrid clustering process which based on: (1) FCM algorithm to get the initial center partition. (2) Genetic algorithms (GA) to achieve optimization and to determine the appropriate cluster centers and the fuzzy corresponding partition matrix. (3) Possibilistic C-Means (PCM) algorithm for volumetric measurements of WM, GM, and CSF brain tissues. (4) Rule of the possibility maximum to compute the labeled image in decision step. The experiments were realized using different real and synthetic brain images from patients with Alzheimer’s disease. We used Tanimoto coefficient, sensitivity and specificity validity indexes to validate the proposed hybrid approach and we compared the performance with several competing methods namely FCM and PCM algorithms. Good result was achieved which demonstrates the efficiency of proposed clustering approach and that it can outperforms competing methods especially in the presence of PVE and when the noise and spatial intensity inhomogeneity are high.

Segmentation of MR Images of the Brain to Detect WM, GM, and CSF Tissues in the Presence of Noise and Intensity Inhomogeneity

ABSTRACTSegmentation of brain MR images for the detection of various healthy brain tissues such as white matter, gray matter, and cerebrospinal fluid is of immense interest to detect and to diagnose different brain-related disorders at the primitive level. MR image segmentation becomes a difficult task owing to the presence of intensity inhomogeneity (IIH), noise, partial volume effects, and intrinsic nature of the MR images. This paper proposes an efficient, region-based, energy minimization technique named as anisotropic multiplicative intrinsic component optimization (AMICO) to segment the brain image in the presence of IIH and noise and to detect different healthy brain tissues. The proposed algorithm utilizes a powerful anisotropic diffusion filter to denoise the image. The MICO algorithm segment the denoised image after correcting IIH. In the proposed technique, MR brain image is decomposed into two multiplicative and intrinsic components, such as the true image component and the bias field component. Brain tissue physical properties are represented by the component of true image and the IIH is characterized by the bias field component. Optimization of these two multiplicative and intrinsic components by employing the proposed effective energy minimization process, result in IIH correction and tissue segmentation simultaneously. The pursuance of the proposed technique is compared with some other existing techniques using the parameters, dice similarity coefficient, sensitivity, specificity, and segmentation accuracy. The results validated the excellent performance of the AMICO in detecting various brain tissues consisting of various levels of IIH and noise.

Reduced distortion artifact whole brain CBF mapping using blip-reversed non-segmented 3D echo planar imaging with pseudo-continuous arterial spin labeling

PurposeTo implement and evaluate interleaved blip-up, blip-down, non-segmented 3D echo planar imaging (EPI) with pseudo-continuous arterial spin labeling (pCASL) and post-processing for reduced susceptibility artifact cerebral blood flow (CBF) maps. Materials and methods3D EPI non-segmented acquisition with a pCASL labeling sequence was modified to include alternating k-space coverage along phase encoding direction (referred to as “blip-reversed”) for alternating dynamic acquisitions of control and label pairs. Eight volunteers were imaged on a 3T scanner. Images were corrected for distortion using spatial shifting transformation of the underlying field map. CBF maps were calculated and compared with maps obtained without blip reversal using matching gray matter (GM) images from a high resolution 3D scan. Additional benefit of using the correction for alternating blip-up and blip-down acquisitions was assessed by comparing to corrected blip-up only and corrected blip-down only CBF maps. Matched Student t-test of overlapping voxels for the eight volunteers was done to ascertain statistical improvement in distortion. ResultsMean CBF value in GM for the eight volunteers from distortion corrected CBF maps was 50.8±9.9ml/min/100 gm tissue. Corrected CBF maps had 6.3% and 4.1% more voxels in GM when compared with uncorrected blip up (BU) and blip down (BD) images, respectively. Student t-test showed significant reduction in distortion when compared with blip-up images and blip-down images (p<0.001). When compared with corrected BU and corrected BD only CBF maps, BU and BD corrected maps had 2.3% and 1% more voxels (p=0.006 and 0.04, respectively). ConclusionPseudo-continuous arterial spin labeling with non-segmented 3D EPI acquisition using alternating blip-reversed k-space traversal and distortion correction provided significantly better matching GM CBF maps. In addition, employing alternating blip-reversed acquisitions during pCASL acquisition resulted in statistically significant improvement over corrected blip-up and blip-down CBF maps.

7T-guided super-resolution of 3T MRI.

High-resolution MR images can depict rich details of brain anatomical structures and show subtle changes in longitudinal data. 7T MRI scanners can acquire MR images with higher resolution and better tissue contrast than the routine 3T MRI scanners. However, 7T MRI scanners are currently more expensive and less available in clinical and research centers. To this end, we propose a method to generate super-resolution 3T MRI that resembles 7T MRI, which is called as 7T-like MR image in this paper. First, we propose a mapping from 3T MRI to 7T MRI space, using regression random forest. The mapped 3T MR images serve as intermediate results with similar appearance as 7T MR images. Second, we predict the final higher resolution 7T-like MR images based on sparse representation, using paired local dictionaries for both the mapped 3T MR images and 7T MR images. Based on 15 subjects with both 3T and 7T MR images, the predicted 7T-like MR images by our method can best match the ground-truth 7T MR images, compared to other methods. Meanwhile, the experiment on brain tissue segmentation shows that our 7T-like MR images lead to the highest accuracy in the segmentation of WM, GM, and CSF brain tissues, compared to segmentations of 3T MR images as well as the reconstructed 7T-like MR images by other methods. We propose a novel method for prediction of high-resolution 7T-like MR images from low-resolution 3T MR images. Our predicted 7T-like MR images demonstrate better spatial resolution compared to 3T MR images, as well as prediction results by other comparison methods. Such high-quality 7T-like MR images could better facilitate disease diagnosis and intervention.

EFFECT OF LEAD ON MALE REPRODUCTION IN EXPERIMENTAL ANIMAL MODEL

Introduction: In early 1960's, there is a first evidence of the toxic effects ionizing radiation on elevated oxygen levels in aerobes and proposed that oxygen toxicity is due to free radical formation. An alteration between oxidants and antioxidants in favour of the oxidants, potentially leading to damage is termed 'oxidative stress'. Lead and cadmium do not have any detectable beneficial biological roles rather it produces detrimental effects on biochemical, physiological and behavioral dysfunctions. Even a little lead poisoning can cause serious health problems, and at very high levels, it can be fatal. Mainly it affects the heamopoeitc system, Liver, Kidney, Cardiovascular system and reproductive system. Methodology: Experimental rats, injected intraperitoneally with lead acetate for 15 days at the dosage of 50, 100 mg/kg/day body weight and compared to control rats injected with deionized distilled water instead. At the end of study testis were removed and right testis was used for testicular antioxidant Malandealdehyde (MDA) levels estimation by Thiobarbituric acid reactive substance assay and left testis was used for histopathological analysis. Unpaired t test and ANOVA was used for statistical analysis. Results : The MDA (nmole /gm tissue) levels in control, lead 50mg, lead 100mg groups were 12.16±0.4, 17.06±0.16 and 18.11±0.13. Histopathology examination Lumen showing decreased sperm count and maturation. Some of the lumens showing absence sperm maturation. Conclusion: Study on lead-exposed rat testis have shown that reduction of spermatogenesis formation and sperm maturation. Increased MDA levels indicate that it may be due to oxidative stress. The toxicity of lead was noted at level ≥50mg/kg. Key words: Lead; Lipid peroxidation; Male reproduction; Testicular histology.

转基因毛状根组织在植物修复研究中的应用进展

毛状根组织是由农杆菌转化植物外植体获得的转基因组织，具有培养简单、生长速度较快、遗传性状和表型特征稳定等优点。近年来毛状根组织在植物修复技术中的应用研究引起了研究者的关注，毛状根组织被作为根的模式体系越来越多地应用于重金属和有机污染物的植物修复技术研究中，已日益成为植物修复技术研究中的一种便捷的实验室研究工具。本文综述了毛状根组织在植物修复中的应用研究进展，包括农业领域重金属污染物的富集，工业领域酚醛、染料和PCBs污染物的去除，军事领域TNT和放射性核素污染物的降解，医药领域抗生素污染物的消除等，并对毛状根组织在植物修复技术研究中的应用前景进行了展望。 Hairy root tissue is a kind of genetically modified (gm) tissue that is obtained by agrobacterium transforming the explant of plants, having the traits of simple cultivating, fast growing, stable genetic and phenotypic characteristics, etc. Recent years the application of hairy root tissue in phytoremediation technology has caused the attention and the hairy root tissue as the model of root system has been increasingly used in the study of the phytoremediation of heavy metals and organic pollutants. Results indicate that hairy root tissue gradually becomes a convenient laboratory research tool in the study of phytoremediation technology. The application and research progress of hairy root tissue in the phytoremediation was reviewed in this paper, including enrichment of heavy metals pollutants in agriculture field; elimination of phenolic, dye, and PCBs pollutants in industry field; degradation of TNT and radionuclide pollutants in military field; remove of antibiotics pollutants in medical field, etc. And the prospects of hairy root tissue used in the phytoremediation research were also discussed.

7T-Guided Learning Framework for Improving the Segmentation of 3T MR Images.

The emerging era of ultra-high-field MRI using 7T MRI scanners dramatically improved sensitivity, image resolution, and tissue contrast when compared to 3T MRI scanners in examining various anatomical structures. The advantages of these high-resolution MR images include higher segmentation accuracy of MRI brain tissues. However, currently, accessibility to 7T MRI scanners remains much more limited than 3T MRI scanners due to technological and economical constraints. Hence, we propose in this work the first learning-based model that improves the segmentation of an input 3T MR image with any conventional segmentation method, through the reconstruction of a higher-quality 7T-like MR image, without actually acquiring an ultra-high-field 7T MRI. Our proposed framework comprises two main steps. First, we estimate a non-linear mapping from 3T MRI to 7T MRI space, using random forest regression model with novel weighting and ensembling schemes, to reconstruct initial 7T-like MR images. Second, we use a group sparse representation with a new pre-selection approach to further refine the 7T-like MR image reconstruction. We evaluated our 7T MRI reconstruction results along with their segmentation results using 13 subjects acquired with both 3T and 7T MR images. For tissue segmentation, we applied two widely used segmentation methods (FAST and SPM) to perform the experiments. Our results showed (1) the improvement of WM, GM and CSF brain tissues segmentation results when guided by reconstructed 7T-like images compared to 3T MR images, and (2) the outperformance of the proposed 7T MRI reconstruction method when compared to other state-of-the-art methods.

Functional cerebral blood volume mapping with simultaneous multi-slice acquisition

The aim of this study is to overcome the current limits of brain coverage available with multi-slice echo planar imaging (EPI) for vascular space occupancy (VASO) mapping. By incorporating simultaneous multi-slice (SMS) EPI image acquisition into slice-saturation slab-inversion VASO (SS-SI VASO), many more slices can be acquired for non-invasive functional measurements of blood volume responses.Blood-volume-weighted VASO and gradient echo blood oxygenation level-dependent (GE-BOLD) data were acquired in humans at 7T with a 32-channel head coil. SMS-VASO was applied in three scenarios: A) high-resolution acquisition of spatially distant brain areas in the visuo-motor network (V1/V5/M1/S1); B) high-resolution acquisition of an imaging slab covering the entire M1/S1 hand regions; and C) low-resolution acquisition with near whole-brain coverage.The results show that the SMS-VASO sequence provided images enabling robust detection of blood volume changes in up to 20 slices with signal readout durations shorter than 150ms. High-resolution application of SMS-VASO revealed improved specificity of VASO to GM tissue without contamination from large draining veins compared to GE-BOLD in the visual cortex and in the sensory-motor cortex.It is concluded that VASO fMRI with SMS-EPI allows obtaining a reasonable three-dimensional coverage not achievable with standard VASO during the short time period when blood magnetization is approximately nulled. Due to the increased brain coverage and better spatial specificity to GM tissue of VASO compared to GE-BOLD signal, the proposed method may play an important role in high-resolution human fMRI at 7T.

Robust volume assessment of brain tissues for 3-dimensional fourier transformation MRI via a novel multispectral technique.

A new TRIO algorithm method integrating three different algorithms is proposed to perform brain MRI segmentation in the native coordinate space, with no need of transformation to a standard coordinate space or the probability maps for segmentation. The method is a simple voxel-based algorithm, derived from multispectral remote sensing techniques, and only requires minimal operator input to depict GM, WM, and CSF tissue clusters to complete classification of a 3D high-resolution multislice-multispectral MRI data. Results showed very high accuracy and reproducibility in classification of GM, WM, and CSF in multislice-multispectral synthetic MRI data. The similarity indexes, expressing overlap between classification results and the ground truth, were 0.951, 0.962, and 0.956 for GM, WM, and CSF classifications in the image data with 3% noise level and 0% non-uniformity intensity. The method particularly allows for classification of CSF with 0.994, 0.961 and 0.996 of accuracy, sensitivity and specificity in images data with 3% noise level and 0% non-uniformity intensity, which had seldom performed well in previous studies. As for clinical MRI data, the quantitative data of brain tissue volumes aligned closely with the brain morphometrics in three different study groups of young adults, elderly volunteers, and dementia patients. The results also showed very low rates of the intra- and extra-operator variability in measurements of the absolute volumes and volume fractions of cerebral GM, WM, and CSF in three different study groups. The mean coefficients of variation of GM, WM, and CSF volume measurements were in the range of 0.03% to 0.30% of intra-operator measurements and 0.06% to 0.45% of inter-operator measurements. In conclusion, the TRIO algorithm exhibits a remarkable ability in robust classification of multislice-multispectral brain MR images, which would be potentially applicable for clinical brain volumetric analysis and explicitly promising in cross-sectional and longitudinal studies of different subject groups.

Evaluating the effects of white matter multiple sclerosis lesions on the volume estimation of 6 brain tissue segmentation methods.

The accuracy of automatic tissue segmentation methods can be affected by the presence of hypointense white matter lesions during the tissue segmentation process. Our aim was to evaluate the impact of MS white matter lesions on the brain tissue measurements of 6 well-known segmentation techniques. These include straightforward techniques such as Artificial Neural Network and fuzzy C-means as well as more advanced techniques such as the Fuzzy And Noise Tolerant Adaptive Segmentation Method, fMRI of the Brain Automated Segmentation Tool, SPM5, and SPM8. Thirty T1-weighted images from patients with MS from 3 different scanners were segmented twice, first including white matter lesions and then masking the lesions before segmentation and relabeling as WM afterward. The differences in total tissue volume and tissue volume outside the lesion regions were computed between the images by using the 2 methodologies. Total gray matter volume was overestimated by all methods when lesion volume increased. The tissue volume outside the lesion regions was also affected by white matter lesions with differences up to 20 cm(3) on images with a high lesion load (≈50 cm(3)). SPM8 and Fuzzy And Noise Tolerant Adaptive Segmentation Method were the methods less influenced by white matter lesions, whereas the effect of white matter lesions was more prominent on fuzzy C-means and the fMRI of the Brain Automated Segmentation Tool. Although lesions were removed after segmentation to avoid their impact on tissue segmentation, the methods still overestimated GM tissue in most cases. This finding is especially relevant because on images with high lesion load, this bias will most likely distort actual tissue atrophy measurements.

A human post-mortem brain model for the standardization of multi-centre MRI studies

Multi-centre MRI studies of the brain are essential for enrolling large and diverse patient cohorts, as required for the investigation of heterogeneous neurological and psychiatric diseases. However, the multi-site comparison of standard MRI data sets that are weighted with respect to tissue parameters such as the relaxation times (T1, T2) and proton density (PD) may be problematic, as signal intensities and image contrasts depend on site-specific details such as the sequences used, imaging parameters, and sensitivity profiles of the radiofrequency (RF) coils. Water or gel phantoms are frequently used for long-term and/or inter-site quality assessment. However, these phantoms hardly mimic the structure, shape, size or tissue distribution of the human brain. The goals of this study were: (1) to validate the long-term stability of a human post-mortem brain phantom, performing quantitative mapping of T1, T2, and PD, and the magnetization transfer ratio (MTR) over a period of 18months; (2) to acquire and analyse data for this phantom and the brain of a healthy control (HC) in a multi-centre study for MRI protocol standardization in four centres, while conducting a voxel-wise as well as whole brain grey (GM) and white matter (WM) tissue volume comparison. MTR, T2, and the quotient of PD in WM and GM were stable in the post-mortem brain with no significant changes. T1 was found to decrease from 267/236ms (GM/WM) to 234/216ms between 5 and 17weeks post embedment, stabilizing during an 18-month period following the first scan at about 215/190ms. The volumetric measures, based on T1-weighted MP-RAGE images obtained at all participating centres, revealed inter- and intra-centre variations in the evaluated GM and WM volumes that displayed similar trends in both the post-mortem brain as well as the HC. At a confidence level of 95%, brain regions such as the brainstem, deep GM structures as well as boundaries between GM and WM tissues were found to be less reproducible than other brain regions in all participating centres. The results demonstrate that a post-mortem brain phantom may be used as a reliable tool for multi-centre MR studies.

Did prostate size affect the complication and outcome of plasmakinetic enucleation of the prostate?

To evaluate surgical complications and outcomes based on prostate size in patients with benign prostatic hyperplasia (BPH) treated with plasmakinetic enucleation of the prostate (PKEP). A retrospective review was conducted of PKEP performed between July 2008 and January 2013. According to the prostate size on preoperative transrectal ultrasonography measurement, patients were divided into three groups: group 1: <40 ml, group 2: 40-80 ml and group 3: >80 ml. Baseline, perioperative and postoperative data were obtained. There were significant differences among the three groups regarding the mean operative time (p < 0.001) and the mean resected tissue weight (p < 0.001). But enucleation efficiency (p < 0.001) in gm tissue per minute increased significantly as prostate size increased. Mean hemoglobin decrease (p > 0.05), mean postoperative irrigation time (p > 0.05), mean catheter time (p > 0.05) and mean hospital stay (p > 0.05) did not differ significantly among three groups. The three groups had a similar and significant postoperative improvement in International Prostate Symptom Score, quality of life, maximum uroflow rate and post-void residual urine volume independent of prostate size (p < 0.001), but no significant difference was found among three groups at the 12-month follow-up (p > 0.05). Perioperative and postoperative complications did not depend on prostate size (p > 0.05). Although patients with a larger BPH required significantly longer operation time in PKEP, prostate size did not affect perioperative and postoperative complications or micturition improvement.