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The viscosity of crude oil plays a pivotal role in the exploration and development of oil fields. The predominant reliance on laboratory measurements, which are constrained by manual expertise, represents a significant limitation in terms of efficiency. Two-dimensional nuclear magnetic resonance (NMR) logging offers a number of advantages over traditional methods. It is capable of providing faster measurement rates, as well as insights into fluid properties, which can facilitate timely adjustments in oil and gas development strategies. This study focuses on the loose sandstone reservoirs with high porosity and permeability containing heavy oil in the Huabei oilfield. Two-dimensional nuclear magnetic resonance (NMR) measurements and analyses were conducted on saturated rocks with different-viscosity crude oils and varying oil saturation levels, in both natural and artificial rock samples. This study elucidates the distribution patterns of different-viscosity crude oils within the two-dimensional NMR spectra. Furthermore, the T1 and T2 peak values of the extracted oil signals were employed to establish a model correlating oil viscosity with NMR parameters. Consequently, a criterion for determining oil viscosity based on two-dimensional NMR was formulated, providing a novel approach for estimating oil viscosity. The application of this technique in the BQ well group of the Huabei oilfield region yielded an average relative error of 15% between the actual oil viscosity and the computed results. Furthermore, the consistency between the oil types and the oil discrimination chart confirms the reliability of the method. The final outcomes meet the precision requirements for practical log interpretation and demonstrate the excellent performance of two-dimensional nuclear magnetic resonance (NMR) logging in calculating oil viscosity. The findings of this study have significant implications for subsequent exploration and development endeavors in the research area's oilfields. [ABSTRACT FROM AUTHOR]

Abstract Background Characterisation of the structure and water status of leaf tissues is essential to the understanding of leaf hydraulic functioning under optimal and stressed conditions. Magnetic Resonance Imaging is unique in its capacity to access this information in a spatially resolved, non-invasive and non-destructive way. The purpose of this study was to develop an original approach based on transverse relaxation mapping by Magnetic Resonance Imaging for the detection of changes in water status and distribution at cell and tissue levels in Brassica napus leaves during blade development and dehydration. Results By combining transverse relaxation maps with a classification scheme, we were able to distinguish specific zones of areoles and veins. The tissue heterogeneity observed in young leaves still occurred in mature and senescent leaves, but with different distributions of T2 values in accordance with the basipetal progression of leaf blade development, revealing changes in tissue structure. When subjected to severe water stress, all blade zones showed similar behaviours. Conclusion This study demonstrates the great potential of Magnetic Resonance Imaging in assessing information on the structure and water status of leaves. The feasibility of in planta leaf measurements was demonstrated, opening up many opportunities for the investigation of leaf structure and hydraulic functioning during development and/or in response to abiotic stresses.

Abstract The purpose of this study was the detection and characterization of synergistic muscle activity. Using T2-map MRI, T2 values for 10 forearm muscles in 11 healthy adult volunteers were obtained in the resting state and after isotonic forearm supination and pronation exercises with the elbow extended. T2 was normalized by Z = (T2e–T2r)/SDr, where T2e was T2 after exercise, while T2r and SDr were the reference values of 34 ms and 3 ms, respectively. Using the cumulative frequency curves of Z values (CFZ), we detected 2 and 3 synergistic muscles for supination and pronation, respectively, and divided these into 2 types, one activated by exercise strength dependently, and the other, independent of exercise strength, activated by only a smaller fraction of the participants. We also detected co-contraction for the supination. Thus, CFZ is a useful visualization tool to detect and characterize not only synergistic muscle, but also co-contraction muscle.

Background: Characterisation of the structure and water status of leaf tissues is essential to the understanding of leaf hydraulic functioning under optimal and stressed conditions. Magnetic Resonance Imaging is unique in its capacity to access this information in a spatially resolved, non-invasive and non-destructive way. The purpose of this study was to develop an original approach based on transverse relaxation mapping by Magnetic Resonance Imaging for the detection of changes in water status and distribution at cell and tissue levels in Brassica napus leaves during blade development and dehydration. Results: By combining transverse relaxation maps with a classification scheme, we were able to distinguish specific zones of areoles and veins. The tissue heterogeneity observed in young leaves still occurred in mature and senescent leaves, but with different distributions of T2 values in accordance with the basipetal progression of leaf blade development, revealing changes in tissue structure. When subjected to severe water stress, all blade zones showed similar behaviours. Conclusion: This study demonstrates the great potential of Magnetic Resonance Imaging in assessing information on the structure and water status of leaves. The feasibility of in planta leaf measurements was demonstrated, opening up many opportunities for the investigation of leaf structure and hydraulic functioning during development and/or in response to abiotic stresses. [ABSTRACT FROM AUTHOR]

The purpose of this study was the detection and characterization of synergistic muscle activity. Using T2-map MRI, T2 values for 10 forearm muscles in 11 healthy adult volunteers were obtained in the resting state and after isotonic forearm supination and pronation exercises with the elbow extended. T2 was normalized by Z = (T2e–T2r)/SDr, where T2e was T2 after exercise, while T2r and SDr were the reference values of 34 ms and 3 ms, respectively. Using the cumulative frequency curves of Z values (CFZ), we detected 2 and 3 synergistic muscles for supination and pronation, respectively, and divided these into 2 types, one activated by exercise strength dependently, and the other, independent of exercise strength, activated by only a smaller fraction of the participants. We also detected co-contraction for the supination. Thus, CFZ is a useful visualization tool to detect and characterize not only synergistic muscle, but also co-contraction muscle. [ABSTRACT FROM AUTHOR]

The viscosity of crude oil plays a pivotal role in the exploration and development of oil fields. The predominant reliance on laboratory measurements, which are constrained by manual expertise, represents a significant limitation in terms of efficiency. Two-dimensional nuclear magnetic resonance (NMR) logging offers a number of advantages over traditional methods. It is capable of providing faster measurement rates, as well as insights into fluid properties, which can facilitate timely adjustments in oil and gas development strategies. This study focuses on the loose sandstone reservoirs with high porosity and permeability containing heavy oil in the Huabei oilfield. Two-dimensional nuclear magnetic resonance (NMR) measurements and analyses were conducted on saturated rocks with different-viscosity crude oils and varying oil saturation levels, in both natural and artificial rock samples. This study elucidates the distribution patterns of different-viscosity crude oils within the two-dimensional NMR spectra. Furthermore, the T1 and T2 peak values of the extracted oil signals were employed to establish a model correlating oil viscosity with NMR parameters. Consequently, a criterion for determining oil viscosity based on two-dimensional NMR was formulated, providing a novel approach for estimating oil viscosity. The application of this technique in the BQ well group of the Huabei oilfield region yielded an average relative error of 15% between the actual oil viscosity and the computed results. Furthermore, the consistency between the oil types and the oil discrimination chart confirms the reliability of the method. The final outcomes meet the precision requirements for practical log interpretation and demonstrate the excellent performance of two-dimensional nuclear magnetic resonance (NMR) logging in calculating oil viscosity. The findings of this study have significant implications for subsequent exploration and development endeavors in the research area’s oilfields.

The method of nuclear magnetic resonance, which is currently the most common in research and control of parameters of condensed matter, and the nuclear magnetic flowmeters and relaxometers that implement this method are described. The features of determining the times of longitudinal and transverse relaxation in nuclear magnetic flowmeters-relaxometers in various modes of medium flow while monitoring its parameters have been established. The advantages of the modulation technique for signal recording in nuclear magnetic flowmeters-relaxometers compared to other recording methods are noted. Using various approximations by the Giulotto method from the Bloch equations, a relation was obtained to determine the longitudinal relaxation time based on the results of measurements of two values of nuclear magnetic resonance signal amplitudes or resonance frequencies at different modulation frequencies. It has been experimentally proven that this relationship has a number of limitations when applied to a flowing liquid. These limitations are associated with the method of recording nuclear magnetic resonance signals and the possibility of their formation at different modulation frequencies of a constant magnetic field, and the amplitudes of the signals differ from each other beyond the measurement error. The reasons that led to such a discrepancy in the ratio of determining the time of longitudinal relaxation have been established. The limits of applicability of the obtained relation are found and it is experimentally proven that within these limits it can be used for reliable measurements of relaxation constants. Based on experimental data, the relationship for determining the longitudinal relaxation time was studied. It has been proven that in a number of cases it is impossible to determine the required time using the specified relationship, although nuclear magnetic resonance signals of the flowing liquid are recorded and it has relaxation times. The results obtained make it possible to eliminate errors when using the nuclear magnetic resonance method to study flowing liquids and solve a number of complex problems in the energy, oil, chemical and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to quantitatively evaluate the whitening process of brown adipose tissue (BAT) in mice using synthetic magnetic resonance imaging (SyMRI) and analyzed the correlation between SyMRI quantitative measurements of BAT and serum lipid profiles. Methods: Fifteen C57BL/6 mice were divided into three groups and fed different diets as follows: normal chow diet for 12 weeks, NCD group; high-fat diet (HFD) for 12 weeks, HFD-12w group; and HFD for 36 weeks, HFD-36w group. Mice were scanned using 3.0 T SyMRI. T1 and T2 values of BAT and interscapular BAT (iBAT) volume were measured. After sacrifice, the body weight of mice, lipid profiles, BAT morphology, and uncoupling protein 1 (UCP1) levels were determined. Statistical analysis was performed using one-way analysis of variance or Kruskal–Wallis test followed by Bonferroni correction for pairwise comparisons. Bonferroni-adjusted significance level was set at P

Purpose: Postexercise recovery rate is a vital component of designing personalized training protocols and rehabilitation plans. Tracking exercise‐induced muscle damage and recovery requires sensitive tools that can probe the muscles' state and composition noninvasively. Methods: Twenty‐four physically active males completed a running protocol consisting of a 60‐min downhill run on a treadmill at −10% incline and 65% of maximal heart rate. Quantitative mapping of MRI T2 was performed using the echo‐modulation‐curve algorithm before exercise, and at two time points: 1 h and 48 h after exercise. Results: T2 values increased by 2%–4% following exercise in the primary mover muscles and exhibited further elevation of 1% after 48 h. For the antagonist muscles, T2 values increased only at the 48‐h time point (2%–3%). Statistically significant decrease in the SD of T2 values was found following exercise for all tested muscles after 1 h (16%–21%), indicating a short‐term decrease in the heterogeneity of the muscle tissue. Conclusion: MRI T2 relaxation time constitutes a useful quantitative marker for microstructural muscle damage, enabling region‐specific identification for short‐term and long‐term systemic processes, and sensitive assessment of muscle recovery following exercise‐induced muscle damage. The variability in T2 changes across different muscle groups can be attributed to their different role during downhill running, with immediate T2 elevation occurring in primary movers, followed by delayed elevation in both primary and antagonist muscle groups, presumably due to secondary damage caused by systemic processes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai Jiaotong University (Science) is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mineral admixtures (MA), like fly ash (FA), silica fume (SF), and slag (S), are usually added to cement-based materials to improve their compactness and further enhance their mechanical properties, permeability resistance, and durability. In this study, low-field nuclear magnetic resonance (LF-NMR) is adopted to explore the evolution of the early hydration characterization of cement-based materials with MA by testing the transverse relaxation time T2. Meanwhile, the effect of MA on mechanical properties is analyzed by measuring compressive and flexural strength. The results show that, in the early hydration (0–7 days), the T2 distribution shows a trend of gradually moving to a short relaxation time and changes from a double peak to a single main peak. The decrease in T2i (main peak vertex) means that the evaporated water is gradually distributed in smaller pores with more motion constraints. However, the type and content of MA have little effect on T2i. Porosity gradually decreases in the period of early hydration. The addition of MA causes the porosity to decrease, and the order influence is FA > S > SF, i.e., the porosities of cement paste with 0%MA, 10%FA + 10%SF, 10%FA + 10%S, and 20%FA at 7 days are 48%, 44.5%, 40.7%, and 40.2%, respectively. Additionally, the addition of MA to cement-based materials also decreases the early strength, and the influence order is FA > S > SF, i.e., the compression strength values of cement paste with 0%MA, 10%FA + 10%SF, 10%FA + 10%S, and 20%FA at 7 days are 47.8 MPa, 40.1 MPa, 38.6 MPa, and 37 MPa, respectively. [ABSTRACT FROM AUTHOR]

Objectives: Evidence regarding placental function in pregnancies complicated by confined placental mosaicism (CPM) is conflicting. We aimed to compare placental function between CPM and non‐CPM pregnancies prenatally and at birth. A secondary objective was to evaluate the relationship between placental function and chromosomal subtype of CPM. Methods: This was a retrospective study of pregnancies with CPM and control pregnancies delivered at a tertiary hospital in Denmark between 2014 and 2017. Placental volume and placental transverse relaxation time (T2*) were estimated on magnetic resonance imaging (MRI), fetal weight and uterine artery pulsatility index (UtA‐PI) were estimated on ultrasound and fetoplacental ratio was assessed on MRI and at birth. These estimates of placental function were adjusted for gestational age and compared between groups using the Wilcoxon rank‐sum test. Within the group of CPM pregnancies, measures of placental function were compared between those at high risk (chromosome numbers 2, 3, 7, 13 and 16) and those at low risk (chromosome numbers 5, 18 and 45X). Results: A total of 90 pregnancies were included, of which 12 had CPM and 78 were controls. MRI and ultrasound examinations were performed at a median gestational age of 32.6 weeks (interquartile range, 24.7–35.3 weeks). On MRI assessment, CPM placentae were characterized by a lower placental T2* Z‐score (P = 0.004), a lower fetoplacental ratio (P = 0.03) and a higher UtA‐PI Z‐score (P = 0.03), compared with non‐CPM placentae. At birth, the fetoplacental ratio was significantly lower (P = 0.02) and placental weight Z‐score was higher (P = 0.01) in CPM pregnancies compared with non‐CPM pregnancies. High‐risk CPM pregnancies showed a reduced placental T2* Z‐score (P = 0.003), lower birth‐weight Z‐score (P = 0.041), earlier gestational age at delivery (P = 0.019) and higher UtA‐PI Z‐score (P = 0.028) compared with low‐risk CPM pregnancies. Low‐risk CPM pregnancies did not differ in any of these parameters from non‐CPM pregnancies. Conclusions: CPM pregnancies are characterized by an enlarged and dysfunctional placenta. Placental function was highly related to the chromosomal type of CPM; placental dysfunction was seen predominantly in high‐risk CPM pregnancies in which chromosomes 2, 3, 7, 13 or 16 were involved. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Cementing technology can effectively extend the life of coalbed methane surface drilling. The fluidity of the cement slurry during cementing is critical to the cementing quality. It is an effective way to improve the cementing quality by increasing the fluidity and pumping efficiency of cement paste by adding dispersants. In this paper, the effect of naphthalene dispersant on the hydration kinetics of G-grade cement was investigated by nuclear magnetic resonance. The results show that the increase of naphthalene dispersant mass fraction can effectively slow down the hydration of cement. The first relaxation peak of cement is correlated with its mobility, and the calculation of its peak index, area size, area share and combined action factor can be used to evaluate the retarding and dispersing effect of naphthalene dispersant on cement slurry more accurately. The main effects of naphthalene dispersant retarding and dispersing are: naphthalene dispersant causes an increase in ξ potential of cement particles, which makes the potential barrier overcome by cement particle coalescence rise; the sulfonic acid group of naphthalene dispersant can form a more stable complex with Ca2+, resulting in a reduced hydration rate. Naphthalene dispersant can decompose in cement into anions adsorbed on the surface of cement particles, forming a solvation film and producing a lubricating and dragging effect. The obtained research results provide theoretical support for the preparation and pumping of on-site cementing slurry from three aspects: the fluidity of the naphthalene dispersant modified cement slurry, the retarding effect and how to choose the pumping period.

Abstract Background MRI is the best imaging tool for the evaluation of uterine tumors, but conventional MRI diagnosis results rely on radiologists and contrast agents (if needed). As a new objective, reproducible and contrast-agent free quantification technique, T2 mapping has been applied to a number of diseases, but studies on the evaluation of uterine lesions and the influence of magnetic field strength are few. Therefore, the aim of this study was to systematically investigate and compare the performance of T2 mapping as a nonenhanced imaging tool in discriminating common uterine lesions between 1.5 T and 3.0 T MRI systems. Methods A total of 50 healthy subjects and 126 patients with suspected uterine lesions were enrolled in our study, and routine uterine MRI sequences with additional T2 mapping sequences were performed. T2 maps were calculated by monoexponential fitting using a custom code in MATLAB. T2 values of normal uterine structures in the healthy group and lesions (benign: adenomyosis, myoma, endometrial polyps; malignant: cervical cancer, endometrial carcinoma) in the patient group were collected. The differences in T2 values between 1.5 T MRI and 3.0 T MRI in any normal structure or lesion were compared. The comparison of T2 values between benign and malignant lesions was also performed under each magnetic field strength, and the diagnostic efficacies of the T2 value obtained through receiver operating characteristic (ROC) analysis were compared between 1.5 T and 3.0 T. Results The mean T2 value of any normal uterine structure or uterine lesion under 3.0 T MRI was significantly lower than that under 1.5 T MRI (p

Nuclear magnetic resonance (NMR) characteristic of hydrates is of great significance for offshore hydrate reservoir exploration and stratigraphic description. The low-field NMR experiments were conducted to explore the relaxation response of tetrabutylammonium bromide (TBAB) aqueous solution during the step cooling and heating processes. The transverse relaxation time spectrum is divided into three intervals: small peak interval ( < 4 ms), medium peak interval (4 ~ 100 ms) and large peak interval ( > 100 ms), and their NMR relaxation signals originate from hydrate, TBAB molecules and water, respectively. Evolution of sample temperature and transverse relaxation time distribution can be used to distinguish the substances contained in the sample, that is, solid hydrate, TBAB aqueous solution, water, and ice. The signal of small peak interval is completely generated by TBAB hydrate, and thus the relationship between the hydrate NMR signal (amplitude and T2 ) and temperature is established, which can be used as a temperature calibration basis for quantitative analysis of hydrate content. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: Therapy for osteoarthritis ideally aims at preserving structure before radiographic change occurs. This study tests: a) whether longitudinal deterioration in cartilage thickness and composition (transverse relaxation-time T2) are greater in radiographically normal knees “at risk” of incident osteoarthritis than in those without risk factors; and b) which risk factors may be associated with these deteriorations. Design: 755 knees from the Osteoarthritis Initiative were studied; all were bilaterally Kellgren Lawrence grade [KLG] 0 initially, and had magnetic resonance images available at 12- and 48-month follow-up. 678 knees were “at risk”, whereas 77 were not (i.e., non-exposed reference). Cartilage thickness and composition change was determined in 16 femorotibial subregions, with deep and superficial T2 being analyzed in a subset (n ​= ​59/52). Subregion values were used to compute location-independent change scores. Results: In KLG0 knees “at risk”, the femorotibial cartilage thinning score (−634 ​± ​516 ​μm) over 3 years exceeded the thickening score by approximately 20%, and was 27% greater (p ​

• Placental volume and transverse relaxation time (T2*) are predictors of small for gestational age (SGA). • In the multi-variate model, placental T2* was the only independent predictor of SGA. • Placental magnetic resonance imaging may improve the antenatal detection of SGA. Placental magnetic resonance imaging (MRI) may be a valuable tool in the prediction of small for gestational age (SGA) at birth. MRI provides reliable estimates of placental volume and thickness. In addition, placental transverse relaxation time (T2*) may be directly related to placental function. This study aimed to explore and compare the predictive performance of three placental MRI parameters – volume, thickness and T2* – in relation to SGA at birth. A mixed cohort of 85 pregnancies was retrieved from the placental MRI database at the study hospital. MRI was performed in a 1.5 T system at gestational weeks 15–41. In normal birthweight (BW) pregnancies [BW > –22 % of expected for gestational age (GA)], the correlation between each of the MRI parameters and GA was investigated by linear regression. The prediction of SGA was investigated by logistic regression analysis adjusted for GA at MRI. In normal BW pregnancies, a significant linear correlation was found between GA and each of the MRI parameters. Univariate analysis demonstrated that placental volume [odds ratio (OR) 0.97, p = 0.001] and placental T2* (OR 0.79, p = 0.003), but not placental thickness (OR 0.92, p = 0.862) were significant predictors of SGA. A multi-variate model including all three MRI parameters found that placental T2* was the only independent predictor of SGA (OR 0.81, p = 0.04). Among the MRI parameters investigated in this study, placental T2* was the only independent predictor of SGA in a multi-variate model. This finding underlines the strong position of T2*-weighted placental MRI in the prediction of SGA. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance (NMR) measurements have been used widely for constructing pseudo-capillary pressure curves. Generating NMR pseudo-capillary pressure curves entails deriving the transverse relaxation time T 2 distribution from the well-known Carr–Purcell–Meiboom–Gill (CPMG) pulse sequence and calibrating the T 2 distribution to laboratory capillary pressure data. A problem with the existing methods using the T 2 distribution to evaluate the capillary pressure curves is that inverting the time-domain CPMG echo decays to the T 2 distribution leads to erroneous results. Noise effects, the ill-posed nature of inversion, and regularization smear the estimated T 2 distribution. Accordingly, this study aimed to furnish a robust and straightforward method to derive in situ capillary pressure curves in water-saturated porous media from the CPMG pulse sequence using wavelet analysis. To this end, the CPMG pulse sequence was divided first into segments of equal length. Then, the discrete wavelet transform (DWT) was employed to upscale each segment to derive T 2 and porosity ϕ NMR . Finally, the cumulative sum of T 2 T 2 c versus the ϕ NMR value was plotted. The resulting pseudo capillary pressure curves ( T 2 c vs. ϕ NMR ) bear a striking resemblance to the capillary pressure curves measured in the laboratory through the centrifuge method. Normalized pseudo capillary pressure curves closely match normalized capillary pressure curves. Consequently, pseudo capillary pressure curves derived in the DWT domain are converted to laboratory capillary pressures curves using a linear transformation. [ABSTRACT FROM AUTHOR]

Background: MRI is the best imaging tool for the evaluation of uterine tumors, but conventional MRI diagnosis results rely on radiologists and contrast agents (if needed). As a new objective, reproducible and contrast-agent free quantification technique, T2 mapping has been applied to a number of diseases, but studies on the evaluation of uterine lesions and the influence of magnetic field strength are few. Therefore, the aim of this study was to systematically investigate and compare the performance of T2 mapping as a nonenhanced imaging tool in discriminating common uterine lesions between 1.5 T and 3.0 T MRI systems. Methods: A total of 50 healthy subjects and 126 patients with suspected uterine lesions were enrolled in our study, and routine uterine MRI sequences with additional T2 mapping sequences were performed. T2 maps were calculated by monoexponential fitting using a custom code in MATLAB. T2 values of normal uterine structures in the healthy group and lesions (benign: adenomyosis, myoma, endometrial polyps; malignant: cervical cancer, endometrial carcinoma) in the patient group were collected. The differences in T2 values between 1.5 T MRI and 3.0 T MRI in any normal structure or lesion were compared. The comparison of T2 values between benign and malignant lesions was also performed under each magnetic field strength, and the diagnostic efficacies of the T2 value obtained through receiver operating characteristic (ROC) analysis were compared between 1.5 T and 3.0 T. Results: The mean T2 value of any normal uterine structure or uterine lesion under 3.0 T MRI was significantly lower than that under 1.5 T MRI (p < 0.05). There were significant differences in T2 values between each lesion subgroup under both 1.5 T and 3.0 T MRI. Moreover, the T2 values of benign lesions (71.1 ± 22.0 ms at 1.5 T and 63.4 ± 19.1 ms at 3.0 T) were also significantly lower than those of malignant lesions (101.1 ± 4.5 ms at 1.5 T and 93.5 ± 5.1 ms at 3.0 T) under both field strengths. In the aspect of differentiating benign from malignant lesions, the area under the curve of the T2 value under 3.0 T (0.94) was significantly higher than that under 1.5 T MRI (0.90) (p = 0.02). Conclusion: T2 mapping can be a potential tool for quantifying common uterine lesions, and it has better performance in distinguishing benign from malignant lesions under 3.0 T MRI. [ABSTRACT FROM AUTHOR]

Single-sided magnetic resonance (SSMR) offers advantages of portability and noninvasive measurement for water detection, with significant potential applications in groundwater exploration, petroleum well logging, and soil moisture monitoring. However, the inherent highly inhomogeneous static magnetic field and radiofrequency (RF) field in SSMR necessitate the utilization of the Carr–Purcell–Meiboom–Gill (CPMG) sequence measurement scheme. To accelerate forward modeling during pulse excitation, we introduce a Geometric Analysis Method (GAM) and assess T 2 error using its primary parameters. The GAM involves applying spatial geometric rotations on the magnetization vector, leading to an analytical solution to the Bloch equation that disregards relaxation effects. Compared with the rotation matrix (RM) method, the GAM demonstrates high accuracy and reduces computational time by approximately 20.9%. By analyzing the primary parameters governing the magnetization vector in the analytical formula, we evaluated their impact on the transverse relaxation time (T 2) obtained through fitting the SE signal. Ultimately, the forward modeling results of the CPMG sequence within the region of interest (ROI) of a single-sided Halbach magnet array are validated. The T 2 fitting error increases as the primary parameters deviate from the ideal values, highlighting their significant role in the T 2 fitting results. This study provides a theoretical foundation for optimizing the design of SSMR magnets and RF coils. • Geometric analytical method (GAM) is proposed to solve the Bloch equation. • Compared with the rotation matrix (RM) method, the GAM demonstrates high accuracy and reduces computational time by approximately 20.9%. • The primary parameters in GAM can be used to evaluate the T 2 fitting error. • This research provides a theoretical basis for optimizing the design of SSMR magnets and RF coils. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the time-course of the physical properties of the psoas major muscle (PM) before and after exercise using magnetic resonance elastography (MRE). Muscle stiffness is one of the important properties associated with muscle function. However, there was no research on the stiffness of the PM after exercise. In this study, we investigated time-course changes of the shear modulus of the PM after exercise. Furthermore, T2 values and apparent diffusion coefficient (ADC), as the additional information associated with muscular physical properties, were also measured simultaneously. Healthy young male volunteers were recruited in this study (n = 9) and they were required to perform a hand-to-knee isometric and unilateral exercise (left side). At each time-point before and after exercise, a set of 3 types of MR scans to measure multiple physical properties of the PM [shear modulus (MRE), T2 values, and ADC] were repeatedly taken. On day 1, a single set MR scan was taken before exercise (pre-exercise MR scan), and 6 sets MR scans were taken (5.5 to 38.0 min after exercise). After about 10-min rest (46.0 to 56.0 min after exercise), 4 sets MR scans were taken (57.5 to 77.0 min after exercise). About 10-min rest was taken again (85.0–95.0 min after exercise), 4 sets MR scans were taken (96.5 to 116.0 min after exercise). On days 2 and 7, a single set MR scan (MRE, T2 value, and ADC) was taken on each experimental day. The data were analyzed as relative changes (%) of the given parameters to the pre-exercise values. The results indicated significant decreases in PM shear modulus up to about 30 min after exercise. Then, it gradually increased and showed significant increases at about 100 min after exercise compared to that before exercise. T2 values and ADC showed significant increases up to about 65 min after exercise compared to those before exercise, and then returned to the pre-exercise values. On days 2 and 7, all values showed no significant changes compared to the pre-exercise values. This study is the first to report the time-course of the physical properties of the PM after exercise. [ABSTRACT FROM AUTHOR]

Low-field magnetic resonance (NMR) technology was applied to measure the transverse relaxation signal intensity and relaxation time of cement paste with different addition of recycled powder, and Scanning Electronic Microscope(SEM) was used to study the influence of recycled powder on early stage hydration and micro-structure of portland cement. The results show that the hydration process of the composite slurry can be divided into four stages: induction stage, acceleration stage, attenuation stage and stable stage. As the hydration goes on, the distribution of the relaxation time T2 of evaporable water in the composite slurry shifts to the direction of short relaxation time. Recycled powder has a high absorption capacity towards water and then release water slowly. During the hydration process, the transverse relaxation time T2 of the sample with a higher proportion of recycled powder always maintains an obvious bimodal distribution. [ABSTRACT FROM AUTHOR]

Synthetic MRI is being increasingly used for the quantification of brain longitudinal relaxation time (T1), transverse relaxation time (T2), and proton density (PD) values. However, the effect of fast imaging protocols on these quantitative values has not been fully estimated. The purpose of this study was to investigate the effect of fast scan parameters on T1, T2, and PD measured with a multi-dynamic multi-echo (MDME) sequence of normal brain at 3.0T. Thirty-four volunteers were scanned using 3 MDME sequences with different scan times (named Fast, 2 min, 29 sec; Routine, 4 min, 07 sec; and Research, 7 min, 46 sec, respectively). The measured T1, T2, and PD in 18 volumes of interest (VOI) of brain were compared between the 3 sequences using rank sum test, t test, coefficients of variation (CVs) analysis, correlation analysis, and Bland-Altman analysis. We found that even though T1, T2, and PD were significantly different between the 3 sequences in most of the brain regions, the intersequence CVs were relatively low and linear correlation were high. Bland-Altman plots showed that most of the values fall within the 95% prediction limits. We concluded that fast imaging protocols of MDME sequence used in our study can potentially be used for quantitative evaluation of brain tissues. Since changing scan parameters can affect the measured T1, T2, and PD values, it is necessary to use consistent scan parameter for comparing or following up cases quantitatively.

Mineral admixtures (MA), like fly ash (FA), silica fume (SF), and slag (S), are usually added to cement-based materials to improve their compactness and further enhance their mechanical properties, permeability resistance, and durability. In this study, low-field nuclear magnetic resonance (LF-NMR) is adopted to explore the evolution of the early hydration characterization of cement-based materials with MA by testing the transverse relaxation time T2. Meanwhile, the effect of MA on mechanical properties is analyzed by measuring compressive and flexural strength. The results show that, in the early hydration (0–7 days), the T2 distribution shows a trend of gradually moving to a short relaxation time and changes from a double peak to a single main peak. The decrease in T2i (main peak vertex) means that the evaporated water is gradually distributed in smaller pores with more motion constraints. However, the type and content of MA have little effect on T2i. Porosity gradually decreases in the period of early hydration. The addition of MA causes the porosity to decrease, and the order influence is FA > S > SF, i.e., the porosities of cement paste with 0%MA, 10%FA + 10%SF, 10%FA + 10%S, and 20%FA at 7 days are 48%, 44.5%, 40.7%, and 40.2%, respectively. Additionally, the addition of MA to cement-based materials also decreases the early strength, and the influence order is FA > S > SF, i.e., the compression strength values of cement paste with 0%MA, 10%FA + 10%SF, 10%FA + 10%S, and 20%FA at 7 days are 47.8 MPa, 40.1 MPa, 38.6 MPa, and 37 MPa, respectively.

The paper justifies the need to improve the primary processing (separation) of oil at a drilling station or on an offshore platform, as well as describing associated problems and determining conditions for increasing the efficiency of the primary oil mixture processing. In order to ascertain the ow rate and control the state of an oil mixture supplied from the well, the authors consider the possibility of using optical instruments and flowmeters of various designs, specifically NMR flowmeter-relaxometers. The design of an industrial M-Phase 5000 NMR flowmeter-relaxometer is described, which is used for monitoring the flow rate and quality of oil and petroleum products; problems that prevent its use at a drilling rig or on an offshore platform are identified. An NMR flowmeter-relaxometer was designed to implement various modulation techniques for measuring the flow rate, as well as longitudinal and transverse relaxation times, of oil mixtures. The application of these techniques and proposed technical solutions allows this instrument to be used at a drilling station and on an offshore platform. The results of studies on various media using the developed instrument are presented. [ABSTRACT FROM AUTHOR]

To detect maize seed vigor under salt-alkaline and drought stress conditions, transverse relaxation time, physiological index, and electron microscopy images of germinating seeds were studied under different stress conditions. The results showed that the water in germinating maize seeds exist in bound water (T 21), semi-bound water (T 22), and free water (T 23), in addition parabolic water (T 24). The Pearson correlation analysis was performed with T 2 relaxation parameters and seed vigor parameters, and this analysis yield nine optimized parameters. To predict vigor levels under different stress conditions, an error backpropagation artificial neural network model was developed, wherein the T 2 chirality parameter was used as the input value, and the seed germination indices of different stress levels were used as the output values. The model could predict the environmental stress level of maize seed growth. The optimized parameter set showed a prediction accuracy of 92.50%, thus outperforming the T 2 relaxation information model without parameter optimization (75.01%). The proposed method can collect data during the germination of maize seeds without any interference and achieve large-scale prediction of seed development status by small sample collection. With the stress environment was aggravated, the physiological structure of seed cells was changed, and the cell structure was destroyed and the ability of water absorption was disappeared. This analysis provides theoretical support and a reference basis for maize planting and production. [Display omitted] • Error backpropagation artificial neural network model (BP-ANN) to predict the vigor level of corn seeds. • The germination of corn seeds is severely affected by salt-alkaline and drought stress. • Nuclear magnetic data of a few corn seeds samples are used to predict the large-scale seed development. [ABSTRACT FROM AUTHOR]

• A paramagnetic Cu2+-induced magnetic resonance tuning (MRET) strategy is proposed. • A Cu–M-MRS immunosensor was constructed for detection of chlorpyrifos and Salmonella. • Fe 3 O 4 @PDA-Ab 2 was used for signal conversion by regulating the amount of Cu2+ ions. • The LOD for chlorpyrifos and Salmonella are 0.05 ng/mL and 50 CFU/mL, respectively. Magnetic relaxation switching (MRS) biosensors have been recognized as useful analytical tools for a range of targets; however, traditional MRS biosensors are limited by the "prozone effect", resulting in a narrow linear range and low sensitivity. Herein, we proposed a paramagnetic Cu2+-induced magnetic resonance tuning (MRET) strategy, based on which Cu2+ ions and magnetic nanoparticles (MNPs) were adopted to construct a Cu–MNP-mediated MRS (Cu–M-MRS) immunosensor with Cu2+ ions acting as a quencher and MNPs as an enhancer. An Fe 3 O 4 @polydopamine-secondary antibody conjugate was prepared and used to correlate the amount of Cu2+ ions to the target concentration through an immunoassay. Based on the immunoreaction, the Cu–M-MRS immunosensor enabled the sensitive detection of chlorpyrifos (0.05 ng/mL, a 77-fold enhancement in sensitivity compared with the traditional MRS immunosensor) and Salmonella (50 CFU/mL). The proposed MRET strategy effectively improved the sensitivity and accuracy of the MRS immunosensor, offering a promising and versatile platform for food safety detection. [ABSTRACT FROM AUTHOR]

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The relevance. Significant part of world hydrocarbons reserves is confined to carbonate reservoirs, which are characterized by complex structure of voids. Reserves estimation and development design of such reservoirs require detailed study of porous media structure, that directly influences the reservoir properties. Identification of petrophysical rock classes is an integral part of hydrocarbons reservoir petrophysical model building. Nuclear magnetic resonance (NMR) method is one of the methods of rock porous structure research and has a number of advantages over other methods. However, there is no information in the published literature about application of this method for petrophysical typing. The results of petrophysical classes identification based on integration of NMR experiments and thin sections description data enhance the quality of reservoir geological and hydrodynamic simulation and hence improve accuracy of hydrocarbons reserves estimation and efficiency of field development. The main aim of the research is carbonate rock petrophysical typing based on integration of NMR experiments and thin sections description data, and estimation of classes identification accuracy with the methods of mathematical statistics. Object: carbonate rocks of Mishrif formation, which is productive in the field of Mesopotamian oil-and-gas province. Methods: analysis of core sample NMR experiments results, thin sections description and routine core analysis, methods of mathematical statistics. Results. Three petrophysical rock types are identified in the log of the well, which intersects productive deposits. The types are: 1st class (wackestone and wackestone/floatstone rock structure), 2nd class (packstone, grainstone and rudstone rock structure) and 3rd class (framestone rock structure). These petrophysical classes are proved with statistical analysis results.

Background: Viral pneumonia (VP) often leads to the development of deep vein thrombosis (DVT) in hospitalized patients. The aim of the study was to investigate the incidence of DVT in discharged patients with VP, and whether new and old DVT differ in transverse relaxation time., Methods: In this prospective cohort study in Wuhan, China, 338 consecutive discharged VP patients from February 2021 to March 2023 who underwent T2 weighted Sampling Perfection with Application Optimized Contrast Evolution (SPACE) were recruited to detect DVT. T2 mapping and T2* mapping were performed for the patients with DVT detected by magnetic resonance imaging (MRI). The minimum, maximum, mean of T2 time and T2* time of DVT were recorded as T2min, T2max, T2mean, T2*min, T2*max, and T2*mean, respectively. Clinical data and laboratory findings were compared between new and old DVT cases, which were defined based on the examination results before and after discharge. A Mann-Whitney test was used to compare transverse relaxation time parameters between new and old DVT., Results: Twelve percent of VP patients (40/338) developed new DVT after discharge. Thirty-three out of 104 DVTs did not resolve after discharge. Compared with patients with new DVT, patients with old DVT were older (67 vs. 59 years, P=0.003); and had a higher proportion of bedridden time >72 hours (72.7% vs. 37.0%, P<0.001). Patients with old DVT had a lower lymphocyte count (0.67×10 9 /L vs. 0.97×10 9 /L, P=0.01), higher C-reactive protein (59 vs. 35 mg/L, P=0.019), and higher levels of D-dimer (6.7 vs. 0.9 µg/mL, P<0.001) than patients with new DVT. Patients with old DVT received more invasive mechanical ventilation (30.3% vs. 7.4%, P<0.001) and had a higher proportion of acute respiratory distress syndrome (75.8% vs. 51.9%, P<0.001), and a higher proportion of cardiac injury (39.4% vs. 14.8%, P=0.033) than patients with new DVT. T2min, T2max, T2mean, and T2*max of new DVT were significantly greater than old DVT (17.6±10.4 vs. 13.2±5.9 ms, 94.9±44.9 vs. 42.3±23.6 ms, 46.8±24.0 vs. 25.0±12.6 ms, 22.5±12.4 vs. 10.7±3.5 ms, P<0.05 for all). There was no significant difference in T2*min or T2*mean between new and old DVT (3.2±0.4 vs. 3.1±0.4 ms, 8.2±4.9 vs. 5.5±1.5 ms, P>0.05 for both)., Conclusions: T2 weighted SPACE magnetic resonance (MR) is valuable in the follow-up of thrombosis of discharged VP patients. T2 mapping distinguishes between new and old DVT., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-23-1607/coif). The authors have no conflicts of interest to declare., (2024 Quantitative Imaging in Medicine and Surgery. All rights reserved.)

The relaxation signal intensity and transverse relaxation time of Portland cement pastes with different dosages of recycled powder at different ages were measured by low-field nuclear magnetic resonance (NMR) technology. Combined with scanning electron microscopy (SEM), the effect of recycled powder on early-age hydration and microstructure of Portland cement was studied. The results show that the hydration process of composite slurry can be divided into four stages, namely, induction period, acceleration period, attenuation period and stable period. As the hydration progressed, the T2 distribution of evaporable water in the composite slurry shifted to short relaxation time, indicating the pores were filled by hydration productions and pore diameter was getting smaller. Recycled powder has high water-adsorption capacity and water slowly-release function, which will lead to the formation of interfacial transition zone (ITZ) and compromise the mechanical property. The transverse relaxation time T2 of samples with higher recycled powder content always maintains obvious bimodal distribution during hydration. [ABSTRACT FROM AUTHOR]

The transverse relaxation time of the spin-exchange optical pumped noble gas nuclei is a fundamental parameter to evaluate the performance of a nuclear magnetic resonance (NMR) rotation sensor. In practical tests and applications, measuring the transverse relaxation time in real-time is challenging. Due to the conflict with feedback loops, the traditional methods are unsuitable for real-time measurement. To address this limitation, this paper proposes a real-time method based on parameter identification to measure the transverse relaxation time. In the proposed method, a step signal is added to the oscillation magnetic field to excite nuclear spins, and the phase response generated is collected for identification. An NMR rotation sensor prototype is developed for the proof of concept. The experimental results verify the effectiveness and the feasibility of the proposed method. [ABSTRACT FROM AUTHOR]

Knowledge of reservoir rock wettability is crucial for the understanding of fluid displacement mechanisms and for adopting feasible solutions to enhance oil recovery. Highly sensitive to the strength of fluid–rock interactions, nuclear magnetic resonance (NMR) measurements are a well-suited candidate for in situ wettability determination. Changes in correlation coefficients between NMR porosity ϕ NMR and transverse relaxation time T 2 can be used as a diagnostic parameter to determine in situ wettability. This paper aimed to take advantage of this promising feature to specify the downhole wettability of an oil well running through two carbonate reservoirs. In this regard, the correlation coefficient between ϕ NMR and T 2 was first computed at each depth. As a superior technique in analyzing nonstationary signals, the wavelet transform was then applied to the correlation coefficient log to remove shale content. Finally, the wavelet transform was re-applied to the modified correlation coefficient log to derive the detail coefficients. Scrutiny of the detail coefficients revealed a strong correlation with experimental wettability results. The results obtained from this investigation indicated that positive detail coefficients are associated with water-wet, and negative ones with oil-wet media. [ABSTRACT FROM AUTHOR]

The relaxation signal intensity and transverse relaxation time of Portland cement pastes with different dosages of recycled powder at different ages were measured by low-field nuclear magnetic resonance (NMR) technology. Combined with scanning electron microscopy (SEM), the effect of recycled powder on early-age hydration and microstructure of Portland cement was studied. The results show that the hydration process of composite slurry can be divided into four stages, namely, induction period, acceleration period, attenuation period and stable period. As the hydration progressed, the T2 distribution of evaporable water in the composite slurry shifted to short relaxation time, indicating the pores were filled by hydration productions and pore diameter was getting smaller. Recycled powder has high water-adsorption capacity and water slowly-release function, which will lead to the formation of interfacial transition zone (ITZ) and compromise the mechanical property. The transverse relaxation time T2 of samples with higher recycled powder content always maintains obvious bimodal distribution during hydration. [ABSTRACT FROM AUTHOR]

We analyzed the correlations between the T2 shift and integrated electromyographic (iEMG) values in the masseter and temporal muscles. Six healthy adults engaged in a clenching task over two durations at various bite forces. We evaluated the mean T2 shift per voxel and assessed their correlations with iEMG using a linear mixed model. The regression coefficients were different for each muscle type, similar for the left and right sides, and decreased upon doubling duration. [ABSTRACT FROM AUTHOR]

Specific features of monitoring the state of a flowing medium by method of nuclear magnetic resonance (NMR) are considered. An approach to studying the state of a flowing medium by monitoring variation of the values of longitudinal (T1) and transverse (T2) relaxation times is justified. Optimum relations between parameters of the system of NMR signal registration and magnetic fields are established. Obeying these relations allows the signal to noise ratio level S/N > 5 to be obtained for measuring the T1 and T2 values online at an error not exceeding 1%. Results of experimental investigations are presented. [ABSTRACT FROM AUTHOR]

Featured Application: Authors are encouraged to provide a concise description of the specific application or a potential application of the work. This section is not mandatory. A growing body of literature shows that the transverse relaxation times of the placenta change during pregnancy and may be an early indicator of disease. Magnetic resonance imaging (MRI) of pregnant women is not, however, currently used frequently despite this evidence. One significant barrier to adoption is the cost of undertaking an MRI scan and the over utilization of existing equipment. Low-field nuclear magnetic resonance (NMR) offers a low-cost alternative, capable of measuring transverse relaxation in a single point in space. Ultrasound imaging (US) is routinely used at several points during pregnancy but is not capable of early detection of pre-eclampsia, for example. It does, however, provide a technique that is capable of locating the placenta with ease. In combination with a single point low-field measurement, localised with ultrasound imaging allows access to this exciting technique without the need for an expensive traditional MRI. In this work, we present a unilateral system (NMR CAPIBarA), operating at a magnetic field of only 18mT, which measures transverse relaxation times at distances from its surface equivalent to the positioning of a human placenta. Data are presented to characterise the system using relation time standards covering the full transverse relaxation time range relevant for the developing placenta, which are also measured on a 1.5 T clinical MRI scanner. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to quantitatively evaluate the whitening process of brown adipose tissue (BAT) in mice using synthetic magnetic resonance imaging (SyMRI) and analyzed the correlation between SyMRI quantitative measurements of BAT and serum lipid profiles., Methods: Fifteen C57BL/6 mice were divided into three groups and fed different diets as follows: normal chow diet for 12 weeks, NCD group; high-fat diet (HFD) for 12 weeks, HFD-12w group; and HFD for 36 weeks, HFD-36w group. Mice were scanned using 3.0 T SyMRI. T1 and T2 values of BAT and interscapular BAT (iBAT) volume were measured. After sacrifice, the body weight of mice, lipid profiles, BAT morphology, and uncoupling protein 1 (UCP1) levels were determined. Statistical analysis was performed using one-way analysis of variance or Kruskal-Wallis test followed by Bonferroni correction for pairwise comparisons. Bonferroni-adjusted significance level was set at P < 0.017 (alpha: 0.05/3 = 0.017)., Results: T2 values of BAT in the HFD-12w group were significantly higher than those in the NCD group (P < 0.001), and those in the HFD-36w group were significantly higher than those in the other two groups (both P < 0.001). The iBAT volume in the HFD-36w group was significantly higher than that in the HFD-12w (P = 0.013) and NCD groups (P = 0.005). T2 values of BAT and iBAT volume were significantly correlated with serum lipid profiles and mouse body weight., Conclusions: SyMRI can noninvasively evaluate the whitening process of BAT using T2 values and iBAT volume, thereby facilitating the visualization of the whitening process., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)