Postprandial splenic stiffness changes on magnetic resonance elastography in a young healthy population.

Magnetic resonance elastography (MRE) is an accurate noninvasive diagnostic tool for assessing the stiffness of parenchymal organs, including the spleen. However, this measurement may be biased due to postprandial changes in splenic stiffness. The aim of the current study was to evaluate postprandial changes in spleen stiffness assessed by MRE in a large sample of healthy volunteers. This was a prospective institutional research ethics board-approved study. Healthy volunteers with no history of liver disease were recruited for an MRE test and blood draw from December 2018 to July 2019. Each participant underwent spleen MRE after at least 4 h of fasting and again 30 min after a 1000 kcal meal. Also, 14 randomly selected volunteers underwent additional MRE examinations at 1.5 and 2.5 h after food intake. The MRE data were acquired at 60 Hz using a 1.5-T MRI scanner. The spleen stiffness was assessed using a weighted mean of stiffness values from regions of interest manually drawn on three to five spleen slices. Spearman's rank correlation, Wilcoxon signed-rank, Friedman, and Mann-Whitney tests were used for statistical analysis. A total of 100 volunteers met the inclusion criteria and were eventually enrolled in this study (age 23 ± 2 years; 65 women). The mean spleen stiffness for the whole group increased by 7.9% (p < 0.001) from the mean ± SD value of 5.09 ± 0.63 (95% CI: 4.96-5.21) kPa in the fasting state to 5.47 ± 0.66 (95% CI 5.34-5.60) kPa 30 min after the meal and then gradually decreased. However, even 2 h 30 min after the meal, the spleen stiffness was higher than in the fasting state. This difference was statistically significant at p less than 0.001. It was concluded that meal intake results in a statistically significant elevation of spleen stiffness that persists for 2.5 h. This finding supports the recommendation for routine fasting for more than 2.5 h prior to assessing MRE-based spleen stiffness.

Spectral signature of multiple sclerosis. Preliminary studies of blood fraction by ATR FTIR technique.

Multiple sclerosis (MS) is a chronic, neurodegenerative disease of central nervous system, characterized by inflammation, demyelination, and gliosis. It is commonly known the rapid and accurate diagnosis of MS determines treatment success. The standard diagnosis contains clinical symptoms observation, magnetic resonance imaging (MRI) of central nervous system (CNS), and analysis of cerebrospinal fluid (CSF). Nonetheless, since CSF sampling is considered invasive and not all individuals are eligible for MRI we have decided to propose other diagnostic tool such as spectroscopy. Unlike lumbar puncture, blood collection is a routine procedure regarded as low-invasive; therefore, we used Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy. This technique was combined with chemometrics and detailed spectral assay to analyse blood plasma and serum samples collected from MS patients and healthy individuals. The results revealed a clear identification pattern of MS, suggesting the conformation changes of amide III collagen-like proteins in plasma and the dominance of amide I ß-sheet structures. Those changes in serum spectra seem to be useful for sample differentiation.

Augmented deep learning model for improved quantitative accuracy of MR-based PET attenuation correction in PSMA PET-MRI prostate imaging.

PURPOSE: Estimation of accurate attenuation maps for whole-body positron emission tomography (PET) imaging in simultaneous PET-MRI systems is a challenging problem as it affects the quantitative nature of the modality. In this study, we aimed to improve the accuracy of estimated attenuation maps from MRI Dixon contrast images by training an augmented generative adversarial network (GANs) in a supervised manner. We augmented the GANs by perturbing the non-linear deformation field during image registration between MRI and the ground truth CT images. METHODS: We acquired the CT and the corresponding PET-MR images for a cohort of 28 prostate cancer patients. Data from 18 patients (2160 slices and later augmented to 270,000 slices) was used for training the GANs and others for validation. We calculated the error in bone and soft tissue regions for the AC µ-maps and the reconstructed PET images. RESULTS: For quantitative analysis, we use the average relative absolute errors and validate the proposed technique on 10 patients. The DL-based MR methods generated the pseudo-CT AC µ-maps with an accuracy of 4.5% more than standard MR-based techniques. Particularly, the proposed method demonstrates improved accuracy in the pelvic regions without affecting the uptake values. The lowest error of the AC µ-map in the pelvic region was 1.9% for µ-mapGAN + aug compared with 6.4% for µ-mapdixon, 5.9% for µ-mapdixon + bone, 2.1% for µ-mapU-Net and 2.0% for µ-mapU-Net + aug. For the reconstructed PET images, the lowest error was 2.2% for PETGAN + aug compared with 10.3% for PETdixon, 8.7% for PETdixon + bone, 2.6% for PETU-Net and 2.4% for PETU-Net + aug.. CONCLUSION: The proposed technique to augment the training datasets for training of the GAN results in improved accuracy of the estimated µ-map and consequently the PET quantification compared to the state of the art.

Accurate hybrid template-based and MR-based attenuation correction using UTE images for simultaneous PET/MR brain imaging applications.

BACKGROUND: Attenuation correction is one of the most crucial correction factors for accurate PET data quantitation in hybrid PET/MR scanners, and computing accurate attenuation coefficient maps from MR brain acquisitions is challenging. Here, we develop a method for accurate bone and air segmentation using MR ultrashort echo time (UTE) images. METHODS: MR UTE images from simultaneous MR and PET imaging of five healthy volunteers was used to generate a whole head, bone and air template image for inclusion into an improved MR derived attenuation correction map, and applied to PET image data for quantitative analysis. Bone, air and soft tissue were segmented based on Gaussian Mixture Models with probabilistic tissue maps as a priori information. We present results for two approaches for bone attenuation coefficient assignments: one using a constant attenuation correction value; and another using an estimated continuous attenuation value based on a calibration fit. Quantitative comparisons were performed to evaluate the accuracy of the reconstructed PET images, with respect to a reference image reconstructed with manually segmented attenuation maps. RESULTS: The DICE coefficient analysis for the air and bone regions in the images demonstrated improvements compared to the UTE approach, and other state-of-the-art techniques. The most accurate whole brain and regional brain analyses were obtained using constant bone attenuation coefficient values. CONCLUSIONS: A novel attenuation correction method for PET data reconstruction is proposed. Analyses show improvements in the quantitative accuracy of the reconstructed PET images compared to other state-of-the-art AC methods for simultaneous PET/MR scanners. Further evaluation is needed with radiopharmaceuticals other than FDG, and in larger cohorts of participants.

Does fine-needle aspiration biopsy still have a place in the diagnosis of breast lesions?

INTRODUCTION: Core needle biopsy is a preferable breast biopsy technique under ultrasound guidance. However, fine-needle biopsy is considered equally popular. AIM OF THE STUDY: To redefine the role of fine-needle aspiration biopsy (FNAB) in the diagnosis of breast lesions. MATERIAL AND METHODS: We retrospectively analysed the medical records of 680 patients who underwent breast ultrasound examination. In most cases, no pathologic structures were observed within the mammary glands. In 321 patients, the presence of focal lesions was revealed, and 107 patients in this group qualified for FNAB according to current recommendations. Patients with suspicious smears were referred for core needle or surgical biopsy. Patients with benign cytological smears underwent repeated ultrasound checks at 6-month intervals during the following year. RESULTS: All the smears were diagnostic. The vast majority of the results were categorised as benign lesions. Cancer cells were detected in six women. In one patient the lesion was classified as suspicious, probably malignant. In all of these cases, open biopsy was performed, and histopathological examination confirmed the presence of a malignant tumour. The patients were given appropriate oncological treatment. For women with benign or suspicious, but probably benign, lesions, breast ultrasound was performed twice at six-month intervals. Control tests showed no significant changes compared to the baseline examination. None of the patients required extensive additional diagnostic tests. CONCLUSIONS: FNAB is a reliable method of assessing pathologic lesions in mammary glands.

Lung function imaging methods in Cystic Fibrosis pulmonary disease.

Monitoring of pulmonary physiology is fundamental to the clinical management of patients with Cystic Fibrosis. The current standard clinical practise uses spirometry to assess lung function which delivers a clinically relevant functional readout of total lung function, however does not supply any visible or localised information. High Resolution Computed Tomography (HRCT) is a well-established current 'gold standard' method for monitoring lung anatomical changes in Cystic Fibrosis patients. HRCT provides excellent morphological information, however, the X-ray radiation dose can become significant if multiple scans are required to monitor chronic diseases such as cystic fibrosis. X-ray phase-contrast imaging is another emerging X-ray based methodology for Cystic Fibrosis lung assessment which provides dynamic morphological and functional information, albeit with even higher X-ray doses than HRCT. Magnetic Resonance Imaging (MRI) is a non-ionising radiation imaging method that is garnering growing interest among researchers and clinicians working with Cystic Fibrosis patients. Recent advances in MRI have opened up the possibilities to observe lung function in real time to potentially allow sensitive and accurate assessment of disease progression. The use of hyperpolarized gas or non-contrast enhanced MRI can be tailored to clinical needs. While MRI offers significant promise it still suffers from poor spatial resolution and the development of an objective scoring system especially for ventilation assessment.

Electromagnetic field (50 Hz) enhance metabolic potential and induce adaptive/reprogramming response mediated by the increase of N6-methyladenosine RNA methylation in adipose-derived mesenchymal stem cells in vitro.

BACKGROUND: Electromagnetic fields (EMF) have an impact on numerous cellular processes. It can positively and negatively affect adipose-derived stem cells (ASCs) thus their fate through the influence of specific factors and protein secretion. EMF can be a great factor for preconditioning ASCs for regenerative medicine purposes, however, understanding the cell's biological response to its effects in vitro is essential. METHODS: ASCs were exposed to the EMF (50 Hz; 1.5 mT) for 24 and 48 h, and then cell biological response was analyzed. RESULTS: 24 h exposure of ASCs to EMF, significantly increased N6-methyladenosine (m6A) RNA methylation, indicating epitranscriptomic changes as an important factor in ASCs preconditioning. Furthermore, the expression of stem cell markers such as Nanog, Oct-4, Sox-2, CD44, and CD105 increased after 24 h of EMF exposure. Besides, western blot analysis showed upregulation of p21 and DNMT2/TRDMT1 protein levels compared to control cells with no differences in the p53 profile. Moreover, after 24 h of exposure to EMF, cell membrane flexibility, the metabolic potential of cells as well as the distribution, morphology, and metabolism of mitochondria were altered. CONCLUSION: ASCs undergo a process of mobilization and adaptation under the EMF influence through the increased m6A RNA modifications. These conditions may "force" ASCs to redefine their stem cell fate mediated by RNA-modifying enzymes and alter their reprogramming decision of as differentiation begins.

High-frequency shear wave MR elastography of parotid glands: custom driver design and preliminary results.

Parotid glands are one of the most common sites for salivary gland tumors. Conventional imaging techniques have limited usefulness in the quantitative assessment of the parotid glands, making it difficult to differentiate between healthy tissue and tumors, as well as between benign and malignant tumors. Magnetic resonance elastography (MRE) is a non-invasive technique that may potentially overcome these limitations. Nevertheless, due to the size of the parotid gland, increased elastographic resolution is required. This may be achieved by applying shear waves at higher frequencies. However, it also results in stronger attenuation, making the illumination of the parotid challenging. Here, we describe a novel passive driver tailored to the anatomy of the human face, which minimizes the distance shear waves need to travel from the source to the area of interest and thus decreases shear wave attenuation, making high-frequency shear wave MRE feasible.

Impact of blocking layers based on TiO2 and ZnO prepared via direct current reactive magnetron sputtering on DSSC solar cells.

The optimization of dye-sensitized solar cells (DSSCs) technology towards suppressing charge recombination between the contact and the electron transport layer is a key factor in achieving high conversion efficiency and the successful commercialization of this type of product. An important aspect of the DSSC structure is the front blocking layer (BL): optimizing this component may increase the efficiency of photoelectron transfer from the dye to the semiconductor by reduction charge recombination at the TiO2/electrolyte and FTO/electrolyte interfaces. In this paper, a series of blocking layer variants, based on TiO2 and ZnO:TiO2, were obtained using the reactive magnetron sputtering method. Material composition, structure and layer thickness were referred to each process parameters. Complete DSSCs with structure FTO/BL/m-TiO2@N719/ EL-HSE/Pt/FTO were obtained on such bases. In the final results, verification of opto-electrical parameters of these cells were tested and used for the conclusions on the optimal blocking layer composition. As the conclusion, application of blocking layer consists of neat TiO2 resulted in improvement of device efficiency. It should be noted that for TiO2:ZnO/CuxO and TiO2/CuxO cells, higher efficiencies were also achieved when pure TiO2 was used as window layer. Additionally it was proven that the admixture of ZnO phase inspires Voc and FF growth, but is overall unfavorable compared to pristine TiO2 blocking layer and the reference cell, according to the final cell efficiency.

3D vector MR elastography applications in small organs.

BACKGROUND: Magnetic resonance elastography (MRE) is a rapidly developing medical imaging technique that allows for quantitative assessment of the biomechanical properties of the tissue. MRE is now regarded as the most accurate noninvasive test for detecting and staging liver fibrosis. A two-dimensional (2D MRE) acquisition version is currently deployed at >2000 locations worldwide. 2D MRE allows for the evaluation of the magnitude of the complex shear modulus, also referred to as stiffness. The development of 3D vector MRE has enabled researchers to assess the biomechanical properties of small organs where wave propagation cannot be adequately analyzed with the 2D MRE imaging approach used in the liver. In 3D vector MRE, the shear waves are imaged and processed throughout a 3D volume and processed with an algorithm that accounts for wave propagation in any direction. Additionally, the motion is also imaged in x, y, and z directions at each voxel, allowing for more advanced processing to be applied. PURPOSE: This review describes the technical principles of 3D vector MRE, surveys its clinical applications in small organs, and discusses potential clinical significance of 3D vector MRE. CONCLUSION: 3D vector MRE is a promising tool for characterizing the biomechanical properties of small organs such as the uterus, pancreas, thyroid, prostate, and salivary glands. However, its potential has not yet been fully explored.

Evaluation of Spleen Stiffness in Young Healthy Volunteers Using Magnetic Resonance Elastography.

PURPOSE: Magnetic resonance elastography (MRE) has been established as the most accurate noninvasive technique for diagnosing liver fibrosis. Recent publications have suggested that the measurement of splenic stiffness is useful in setting where portal hypertension may be present. The goal of the current study was to compile normative data for MRE-assessed stiffness measurements of the spleen in young adults. MATERIALS AND METHODS: A total of 100 healthy young Caucasian volunteers (65 females and 35 males) in the age range of 20 to 32 years were enrolled in this study. The participants reported no history of chronic spleen and liver disease, normal alcohol consumption, and a normal diet. The MRE data were acquired by using a 1.5 T whole-body scanner and a 2D GRE pulse sequence with 60 Hz excitation. Spleen stiffness was calculated as a weighted mean of stiffness values in the regions of interest manually drawn by the radiologist on three to five spleen slices. RESULTS: Mean spleen stiffness was 5.09 ± 0.65 kPa for the whole group. Male volunteers had slightly higher splenic stiffness compared to females: 5.28 ± 0.78 vs. 4.98 ± 0.51 kPa, however, this difference was not statistically significant (p = 0.12). Spleen stiffness did not correlate with spleen fat content and liver stiffness but a statistically significant correlation with spleen volume was found. CONCLUSIONS: The findings of this study provide normative values for 2D MRE-based measurement of spleen stiffness in young adults, a basis for assessing the value of this biomarker in young patients with portal system pathologies.

Carotenoids contribution in rapid diagnosis of multiple sclerosis by Raman spectroscopy.

Rapid and accurate diagnosis of any illness determines the success of treatment. The same applies to multiple sclerosis (MS), chronic, inflammatory, and neurodegenerative diseases (ND) of the central nervous system (CNS). Unfortunately, the definitive diagnosis of MS is prolonged and involves mainly clinical symptoms observation and magnetic resonance imaging (MRI) of the CNS. However, as we previously reported, Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy shed new light on the minimally invasive, label-free, and rapid diagnosis of this illness through blood fraction. Herein we introduce Raman spectroscopy coupled with chemometric analysis to provide more detailed information about the biochemical changes behind MS. This pilot study demonstrates that mentioned combination may provide a new diagnostic biomarker and bring closer to rapid MS diagnosis. It has been shown that Raman spectroscopy provides lipid and carotenoid molecules as useful biomarkers which may be applied for both diagnosis and treatment monitoring.

Viscosity of suspensions of yttrium oxide (Y2O3) nanopowder in ethyl alcohol.

This paper presents results from measurements of viscosity of suspensions of Yttrium Oxide Y2O3 ceramic nanopowder in ethyl alcohol. The study was conducted at the request of and in cooperation with the ICMB. This research will add important information about the formation and viscosity characteristics of suspensions of nanopowders. The behavior of nanopowder suspensions has been examined in a wide range of shear rates from 0.01 s(-1) to 2000 s(-1). Additionally, the behavior of the suspension has been studied in the temperature range from -15 degrees C to 20 degrees C. Complementary experiments have been performed by application of a Rheo-NMR at Bruker Biospin and by the use of RheoScope at ThermoFisher companies.

Characterisation of breast cancer molecular signature and treatment assessment with vibrational spectroscopy and chemometric approach.

Triple negative breast cancer (TNBC) is regarded as the most aggressive breast cancer subtype with poor overall survival and lack of targeted therapies, resulting in many patients with recurrent. The insight into the detailed biochemical composition of TNBC would help develop dedicated treatments. Thus, in this study Fourier Transform Infrared microspectroscopy combined with chemometrics and absorbance ratios investigation was employed to compare healthy controls with TNBC tissue before and after chemotherapy within the same patient. The primary spectral differences between control and cancer tissues were found in proteins, polysaccharides, and nucleic acids. Amide I/Amide II ratio decrease before and increase after chemotherapy, whereas DNA, RNA, and glycogen contents increase before and decrease after the treatment. The chemometric results revealed discriminatory features reflecting a clinical response scheme and proved the chemotherapy efficacy assessment with infrared spectroscopy is possible.

TiO2/CuO/Cu2O Photovoltaic Nanostructures Prepared by DC Reactive Magnetron Sputtering.

In this study, titanium dioxide/copper oxide thin-film solar cells were prepared using the reactive direct-current magnetron sputtering technique. The influence of the deposition time of the top Cu contact layer on the structural and electrical properties of photovoltaic devices was analyzed. The structural and morphological characterization of the TiO2/CuO/Cu2O solar cells was fully studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and current-voltage (I-V) characteristics. Additionally, using van der Pauw sample geometries, the electrical properties of the titanium dioxide and copper oxide layers were investigated. From the XRD study, solar cells were observed in cubic (Cu2O), monoclinic (CuO), and Ti3O5 phases. In addition, the crystallite size and dislocation density for copper oxide layers were calculated. Basic morphological parameters (thickness, mechanism of growth, and composition of elements) were analyzed via scanning electron microscopy. The thicknesses of the titanium dioxide and copper oxide layers were in the range of 43-55 nm and 806-1223 nm, respectively. Furthermore, the mechanism of growth and the basic composition of the elements of layers were analyzed. The I-V characteristic curve confirms the photovoltaic behavior of two titanium dioxide/copper oxide thin-film structures. The values of short-circuit current density (Jsc) and open-circuit voltage (Voc) of the solar cells were: 4.0 ± 0.8 µA/cm2, 16.0 ± 4.8 mV and 0.43 ± 0.61 µA/cm2, 0.54 ± 0.31 mV, respectively. In addition, the authors presented the values of Isc, Pmax, FF, and Rsh. Finally, the resistivity, carrier concentration, and mobility are reported for selected layers with values reflecting the current literature.

DNA damage and repair kinetics after microbeam radiation therapy emulation in living cells using monoenergetic synchrotron X-ray microbeams.

A novel synchrotron-based approach, known as microbeam radiation therapy (MRT), currently shows considerable promise in increased tumour control and reduced normal tissue damage compared with conventional radiotherapy. Different microbeam widths and separations were investigated using a controlled cell culture system and monoenergetic (5.35 keV) synchrotron X-rays in order to gain further insight into the underlying cellular response to MRT. DNA damage and repair was measured using fluorescent antibodies against phosphorylated histone H2AX, which also allowed us to verify the exact location of the microbeam path. Beam dimensions that reproduced promising MRT strategies were used to identify useful methods to study the underpinnings of MRT. These studies include the investigation of different spatial configurations on bystander effects. γH2AX foci number were robustly induced in directly hit cells and considerable DNA double-strand break repair occurred by 12 h post-10 Gy irradiation; however, many cells had some γH2AX foci at the 12 h time point. γH2AX foci at later time points did not directly correspond with the targeted regions suggesting cell movement or bystander effects as a potential mechanism for MRT effectiveness. Partial irradiation of single nuclei was also investigated and in most cases γH2AX foci were not observed outside the field of irradiation within 1 h after irradiation indicating very little chromatin movement in this time frame. These studies contribute to the understanding of the fundamental radiation biology relating to the MRT response, a potential new therapy for cancer patients.

The Dynamic(s) of Adipose Stem Cell System, Their Survival, and Cessation under the Influence of Electromagnetic Fields.

CONTEXT: The electromagnetic field (EMF) is one of the external biophysical factors that can influence stem cells' structure and functionality. Depending on its frequency and magnetic flux density, EMF can have both a positive and negative effect on stem cell biology. AIMS: The aim of the study is to define EMF conditions that support beneficial physiological processes and those that lead to pathophysiological phenomena. Understanding the changes and processes occurring in stem cells after exposure to EMFs of different parameters can be an important factor to be applied in stem cell-based therapies and regenerative medicine. MATERIALS AND METHODS: In this study, using fluorescent microscopy and flow cytometry methods, the influence of EMF on adipose-derived stem cells proliferation, cell cycle, viability, and death were examined. EMF parameters were set in accordance with the ion cyclotron resonance (ICR) theory that influences Ca2+ and Mg2+ ions influx. Results were statistically developed using the ANOVA and effect size (Cohen's d) analyses. RESULTS: In this study, the continuous exposure of adipose-derived stem cells to EMF (ICR parameters: 76.6 Hz; 20 µT) causes a statistically significant increase in cell death through the enhancement of apoptotic, necrotic, and autophagic cell numbers. Apart from increased cell deaths after EMF exposure, increased proliferation after 24 h of EMF exposure has been also observed. CONCLUSIONS: Results presented in this study show that EMF influences stem cell dynamics resulting in a significantly increased cell death, thus altering the stem cell fate. It is important to further establish EMF conditions that support ASCs functioning and beneficial physiological processes for future regenerative medical purposes.

In search of nano-materials with enhanced secondary electron emission for radiation detectors.

There has been limited research devoted to secondary electron emission (SEE) from nano-materials using rapid and heavy ion bombardment. Here we report a comparison of SEE properties between novel nano-materials with a three-dimensional nano-structure composed of a mostly regular pattern of rods and gold used as a standard material for SEE under bombardment of heavy ions at energies of a few MeV/nucleon. The nano-structured materials show enhanced SEE properties when compared with gold. Results from this work will enable the development of new radiation detectors for science and industry.

Postprandial hepatic stiffness changes on magnetic resonance elastography in healthy volunteers.

Magnetic resonance elastography (MRE) is a reliable noninvasive method for assessment of hepatic stiffness. Liver stiffness is known to be affected by elevated postprandial portal blood flow in patients with chronic liver disease. The goal of this study was to determine whether food intake affects liver stiffness in the absence of known liver disease. We evaluated 100 volunteers (35 men and 65 women) who met inclusion criteria. The subjects had two MRE examinations, first while fasting and then 30 min after a test meal. Fourteen subjects also had two additional MRE exams 1 h 30 min and 2 h 30 min after the meal. Liver stiffness was measured by placing the largest possible polygon ROIs on the four widest liver slices and calculated as a mean of stiffness values from each slice. The correlation of liver stiffness values before and after the meal was assessed using a paired t-test. To evaluate the relationship between the change in postprandial liver stiffness and fasting liver stiffness values, linear regression was performed. The liver stiffness values in the fasting state ranged from 1.84 to 2.82 kPa, with a mean of 2.30 ± 0.23 kPa (95% CI 2.25-2.34). At 30 min after the meal, liver stiffness values ranged from 2.12 to 3.50 kPa, with a mean of 2.70 ± 0.28 kPa (95% CI 2.64-2.75), demonstrating a systematic postprandial increase by 0.40 ± 0.23 kPa (17.7 ± 3.5%). Meal intake significantly increases liver stiffness in healthy individuals, which persists for at least 2 h 30 min. Patients should fast for 3-4 h before MRE examinations to avoid fibrosis overstaging due to postprandial liver stiffness augmentation.

Value of liver iron concentration in healthy volunteers assessed by MRI.

Iron overload is a relatively common clinical condition resulting from disorders such as hereditary hemochromatosis, thalassemia, sickle cell disease, and myelodysplasia that can lead to progressive fibrosis and eventually cirrhosis of the liver. Therefore, it is essential to recognize the disease process at the earliest stage. Liver biopsy is the reference test for the assessment of liver fibrosis. It also allows for quantifying liver iron concentration (LIC) in patients. However, this is an invasive method with significant limitations and possible risks. Magnetic resonance imaging (MRI) and evaluation of the R2* relaxation rate can be an alternative to biopsy for assessing LIC. However, it causes a need for accurate R2* data corresponding to standard value for further comparison with examined patients. This study aimed to assess the normative values of liver R2* in healthy individuals. A total of 100 volunteers that met established criteria were enrolled in the study: 36 (36%) men and 64 (64%) women. The mean age was 22.9 years (range 20 to 32 years). R2* was estimated by an MRI exam with a 1.5 T clinical magnetic resonance scanner. Images for measuring the LIC and liver fat concentration were obtained using the IDEAL-IQ technique for liver imaging. The Mean (SD) liver R2* was 28.34 (2.25) s-1 (95% CI, 27.78-28.90, range 23.67-33.00 s-1) in females, 29.57 (3.20) s-1 (95% CI, 28.49-30.66, range 23.93-37.77 s-1) in males, and 28.72 (2.69) s-1 (range 23.67-37.77 s-1) in the whole group. R2* value in this particular population with a high proportion of young women did not exceed 38 s-1. In the absence of fibrosis or steatosis, liver stiffness and fat fraction did not show any relationship with R2*.