Magnetic Resonance Studies Research Articles

Gender-affirming hormone therapy and its impact on myocardial mass and cardiac function: a prospective magnetic resonance study on transgender men and women

Gender-affirming hormone therapy and its impact on myocardial mass and cardiac function: a prospective magnetic resonance study on transgender men and women

Magnetic resonance study of rare-earth titanates

Magnetic resonance study of rare-earth titanates

Capturing of neurotoxins causing diabetes stress and nervous breakdown in the aqueous medium by naphthazarin esters.

The fear of an increase in blood sugar can be very traumatic. Being diabetic either type I or type II leads to a disorder called diabetes distress having traits of stress, depression, and anxiety. Among risk factors of diabetes mellitus heavy and trace metal toxicity emerges as new risk factors reported in many studies. In this study we target toxic metals, viz., Ni2+, Zn2+, and Cu2+, involved in the pathogenesis of diabetes and diabetic stress with naphthazarin esters. The compounds C1-C3 isolated from the leaves and roots of Arnebia guttata were tested for their metal-binding ability in an aqueous medium in UV-Visible and nuclear magnetic resonance (NMR) studies. These probes are well-known naphthoquinones present in the Arnebia species. In the UV-Visible titrations of compounds C1-C3 with Na2+, K2+, Zn2+, Ca2+, Cu2+, Mg2+, Co2+, and Ni2+ ions, significant binding was observed with Ni2+, Cu2+, and Zn2+ ions in MeOH/H2O. There occurs a beautiful formation of red-shifted bands between the 520 to 620 nm range with a synergistic increase in absorbance. Also, the disappearance of proton peaks in the 1H NMR spectrum on addition of metal ions confirmed binding. Compounds C1-C3 isolated from A. guttata came out as potent Ni2+, Zn2+, and Cu2+ sensors that are reportedly involved in islet function and induction of diabetes.

Saponins from seeds of Zizyphus jujuba Mill. var. spinosa exhibit vasorelaxant effects on rat isolated aorta

AbstractAimThe vasorelaxant saponins jujuboside A(1), A1(2), B(3), and acetyljujuboside B(4) were isolated from 50% MeOH extracts of seeds of Zizyphus jujuba Mill. var. spinosa Hu ex H.F. Chou (Rhamnaceae), and their effects were studied using isolated rat aortic rings.MethodDried jujube seeds were crushed and extracted with 50% MeOH, and the extracts were concentrated under reduced pressure. Vasorelaxant effects of this extracts were assessed on rat isolated aorta rings. The aorta rings were placed in a well‐oxygenated bath of modified Krebs–Henseleit solution and the mechanical tension was measured isometrically.ResultsThe crude extract was fractionated by chromatographic methods with the guidance of vasorelaxant activity, and four saponins (1~4) were isolated. These compounds were identified using nuclear magnetic resonance (NMR) studies. Compounds 1~4 showed slow relaxation activity against norepinephrine (NE)‐induced contractions of rat aorta with/without endothelium. Treatment with 1~4 did not significantly inhibit NE‐induced vasoconstrictions. Compounds 1~4 inhibited vasoconstriction induced by high‐concentration potassium (60 mM) and NE in the presence of nicardipine but did not affect phorbol 12‐myristate 13‐acetate‐induced vasoconstriction.ConclusionThese results suggest that inhibition of NE‐induced vasoconstriction by 1~4 is due to the inhibition of receptor‐operated Ca2+ channels and voltage‐dependent Ca2+ channels or inhibition of intracellular calcium modulations.

Beyond the permeability barriers: Unveiling the potential of dual-crosslinking hydrogel nanofiltration membranes for high-performance molecular/ion sieving

Membrane separation technology has shown great potential in resource recovery, energy utilization, and environmental protection, attracting extensive attention for the various practical applications. The alginate-based hydrogel membrane, derived from natural biomass, possesses sustainability and anti-fouling properties, effectively reducing the burden of waste membrane disposal. However, the limitations of alginate hydrogel include its high swelling ability, low permeability, and poor mechanical properties. In this study, we propose a straightforward method to fabricate orderliness hydrogels by employing lanthanide ion via dual cross-linking with CaAlg, resulting in the formation of lanthanum calcium alginate (La-CaAlg) hydrogel membrane. The La-CaAlg membrane exhibits superior mechanical performance and anti-swelling properties compared to LaAlg and CaAlg membranes. Additionally, through small-angle scattering and low-field nuclear magnetic resonance studies on the membrane's spatial orientation, and pore size distribution, we gained the comparable results into its internal structure for the design insight. Notably, the La-CaAlg membrane demonstrates outstanding performance in dye/salt separation, showcasing high selectivity and permeability. We propose the strategy that enhances the orderliness and durability of the alginate hydrogel membrane, providing the separation design insight to overcome the limitations associated with the permeability and rejection trade-off.

Inflammation Links Cardiac Injury and Renal Dysfunction: A Cardiovascular Magnetic Resonance Study.

Inflammation is essential in cardiorenal syndrome, however there is still a lack of evidence proving the interaction between cardiac injury, renal dysfunction and the inflammatory response. This study aimed to illustrate the association between renal dysfunction and cardiac injury with a specific focus on the role of inflammation. A single-center, retrospective study included patients with heart failure admitted to the cardiovascular department from September 2019 to April 2022. Patients received cardiovascular magnetic resonance (CMR) imaging (T1 mapping and late gadolinium enhancement (LGE)). Demographic, creatinine and native T1 were analyzed using pearson correlation, linear regression and adjusted for confounders. Interaction and subgroup analysis were performed. Finally, 50 validated heart failure (HF) patients (age 58.5 14.8 years; 78.0% men) were included. Cardiac global native T1 for the high estimated glomeruar filtration rate (eGFR) group was 1117.0 56.6 ms, and for the low eGFR group was 1096.5 61.8 ms. Univariate analysis identified global native T1 ( = 0.16, 95% confidence interval (CI): 0.04-0.28, p = 0.014) and C-reactive protein (CRP) ( = 0.30, 95% CI: 0.15-0.45, p 0.001) as determinants of creatinine. Multivariable linear regression analysis identified global native T1 ( = 0.12, 95% CI: 0.01-0.123, p = 0.040) as a determinant of creatinine while age and diabetes were adjusted. Significant interactions between CRP and global native T1 in relation to creatinine level (p for interaction = 0.005) were identified. Kidney dysfunction was associated with cardiac injury and inflammation, respectively. The interaction between myocardial injury and kidney dysfunction is contingent on the severity of the inflammatory response. Further studies were needed to identify the mechanisms of the inflammatory response in cardiorenal syndrome.

Magnetic Resonance Study of Bulky CVD Diamond Disc.

Diamonds produced using chemical vapor deposition (CVD) have found many applications in various fields of science and technology. Many applications involve polycrystalline CVD diamond films of micron thicknesses. However, a variety of optical, thermal, mechanical, and radiation sensing applications require more bulky CVD diamond samples. We report the results of a magnetic resonance and structural study of a thick, sizable polycrystalline CVD diamond disc, both as-prepared and treated with e-beam irradiation/high-temperature annealing, as well as gamma irradiation. The combination of various magnetic resonance techniques reveals and enables the attribution of a plentiful collection of paramagnetic defects of doublet and triplet spin origin. Analysis of spectra, electron, and nuclear spin relaxation, as well as nuclear spin diffusion, supports the conclusion of significant macro- and micro-inhomogeneities in the distribution of nitrogen-related defects.

Improved Recovery of Complete Spinal Cord Transection by a Plasma-Modified Fibrillar Scaffold.

Complete spinal cord injury causes an irreversible disruption in the central nervous system, leading to motor, sensory, and autonomic function loss, and a secondary injury that constitutes a physical barrier preventing tissue repair. Tissue engineering scaffolds are presented as a permissive platform for cell migration and the reconnection of spared tissue. Iodine-doped plasma pyrrole polymer (pPPy-I), a neuroprotective material, was applied to polylactic acid (PLA) fibers and implanted in a rat complete spinal cord transection injury model to evaluate whether the resulting composite implants provided structural and functional recovery, using magnetic resonance (MR) imaging, diffusion tensor imaging and tractography, magnetic resonance spectroscopy, locomotion analysis, histology, and immunofluorescence. In vivo, MR studies evidenced a tissue response to the implant, demonstrating that the fibrillar composite scaffold moderated the structural effects of secondary damage by providing mechanical stability to the lesion core, tissue reconstruction, and significant motor recovery. Histologic analyses demonstrated that the composite scaffold provided a permissive environment for cell attachment and neural tissue guidance over the fibers, reducing cyst formation. These results supply evidence that pPPy-I enhanced the properties of PLA fibrillar scaffolds as a promising treatment for spinal cord injury recovery.

Coupling of source rock gas expulsion intensity and reservoir quality in time and space-a key to determine gas accumulation in Upper Paleozoic tight sandstones of the Mugua gas field, Ordos Basin, China

Research on gas accumulation mechanisms and variations in gas saturation is limited in the newly established Mugua gas field in the Ordos Basin. Understanding these aspects is vital for reduce drilling uncertainty and exploration risk. This study employed a variety of methods, including: (1) the use of organic geochemical examinations to determine the gas expulsion intensity of hydrocarbon source rocks; (2) fluid inclusion analyses to determine the time of gas accumulation; (3) a combination of optical microscopy, scanning electron microscopy observations, pore-simulation and permeability tests, mercury-intrusion capillary pressure experiments, and nuclear magnetic resonance studies to assess the properties of the reservoir quality and identify the tight sandstone rock type; (4) wireline logging and interpretive data analyses to research the gas saturations features; and (5) establish reservoir quality evolution model to systematically study this problem. Integrating fluid inclusion homogenization temperatures with burial and thermal histories indicates that gas accumulation in the Mugua gas fields occurred throughout the Early Jurassic to Late Cretaceous period. Five diagenetic facies have been identified: dissolution, quartz-cemented, clay mineral filling, tightly compacted, and carbonate-cemented facies. The reservoir quality evolution model reveals that the five diagenetic facies experienced densification before the period of gas accumulation. Therefore, for gas accumulation in tight sandstones, it is essential that mature and gas-generating source rocks, provide sufficient expulsion forces to drive gas into the rocks. The mechanism of gas accumulation in the Mugua gas field's tight gas sandstone reservoirs involves the process occurring in sandstones that are either near or interbedded with source rocks, under high pore-fluid pressure generated by gas production. Compared to other Upper Paleozoic gas fields in the Ordos Basin, the gas expulsion intensity in the Mugua gas field is lower, ranging from 6.12–8.39 × 108 m3/km2. Due to the low gas expulsion intensity, the Shihezi 8 Member's tight sandstone reservoirs, situated away from the source rock, typically show low gas saturation. Conversely, the dissolution and quartz-cemented facies within the Benxi, Taiyuan, and Shanxi Formations, intimately interbedded with hydrocarbon source rocks, exhibit good reservoir quality. They offer ideal conditions for gas accumulation, making them prime candidates for exploration and development.

Can Automated 3-Dimensional Dixon-Based Methods Be Used in Patients With Liver Iron Overload?

Accurate quantification of liver iron concentration (LIC) can be achieved via magnetic resonance imaging (MRI). Maps of liver T2*/R2* are provided by commercially available, vendor-provided, 3-dimensional (3D) multiecho Dixon sequences and allow automated, inline postprocessing, which removes the need for manual curve fitting associated with conventional 2-dimensional (2D) gradient echo (GRE)-based postprocessing. The main goal of our study was to investigate the relationship among LIC estimates generated by 3D multiecho Dixon sequence to values generated by 2D GRE-based R2* relaxometry as the reference standard. A retrospective review of patients who had undergone MRI scans for estimation of LIC with conventional T2* relaxometry and 3D multiecho Dixon sequences was performed. A 1.5 T scanner was used to acquire the magnetic resonance studies. Acquisition of standard multislice multiecho T2*-based sequences was performed, and R2* values with corresponding LIC were estimated. The comparison between R2* and corresponding LIC estimates obtained by the 2 methods was analyzed via the correlation coefficients and Bland-Altman difference plots. This study included 104 patients (51 male and 53 female patients) with 158 MRI scans. The mean age of the patients at the time of scan was 15.2 (SD, 8.8) years. There was a very strong correlation between the 2 LIC estimation methods for LIC values up to 3.2 mg/g (LIC quantitative multiecho Dixon [qDixon; from region of interest R2*] vs LIC GRE [in-house]: r = 0.83, P < 0.01; LIC qDixon [from segmentation volume R2*] vs LIC GRE [in-house]: r = 0.92, P < 0.01); and very weak correlation between the 2 methods at liver iron levels >7 mg/g. Three-dimensional-based multiecho Dixon technique can accurately measure LIC up to 7 mg/g and has the potential to replace 2D GRE-based relaxometry methods.

Correlation between MR semiotics and intensity of pelvic pain syndrome in female patients with deep infiltrating endometriosis of the posterior pelvic compartment

Objective. To identify the correlation between magnetic resonance (MR) semiotics and the intensity of pelvic pain syndrome in female patients with deep infiltrating endometriosis of the posterior pelvic compartment. Material and methods. We performed a retro- and prospective analysis of MR studies of pelvic organs in 77 female patients with pelvic pain syndrome, aged from 24 to 39 years. We assessed the intensity of the pain syndrome using a visual analog scale (VAS). The patients were divided into 2 groups: 1st-patients with external genital endometriosis (EGE) without involving the posterior pelvic compartment, 2nd-patients with EGE of the posterior pelvic compartment. The patients of the second group were divided into subgroups: 1 – endometriosis of the posterior pelvic compartment without MR signs of intestinal wall invasion, 2 – posterior compartment endometriosis with MR signs of intestinal wall invasion. The study was conducted on a GE Signa 1.5 Tesla MRI scanner. Results. In the second group of patients with endometriosis of the posterior pelvic compartment, the pain syndrome (8.00 (7.00–9.00) was more intense than in the first group of patients without endometriosis of the posterior pelvic compartment 7.00 (5.00–7.00), p&lt;0.001 and we evaluated a retrovaginal, retrocervical and posterior uterine localization. In the second subgroup of patients with signs of the intestinal wall invasion, the pelvic pain syndrome on the VAS was statistically significantly more intense 8.00 (8.00-10.00) than in the first subgroup of patients without signs of the intestinal wall invasion 7.00 (6.00–7.00) (P&lt;0.001). Conclusion. Patients with identified deep infiltrating endometriosis of the posterior pelvic compartment have more pronounced manifestations of the pelvic pain syndrome then patients with endometriosis of other localizations.

Gender differences in the impact of anatomical factors on non-contact anterior cruciate ligament injuries: a magnetic resonance study

PurposeTo identify MRI-detected anatomical risk factors for non-contact anterior cruciate ligament (ACL) injuries across genders.MethodsA retrospective analysis was performed on 141 ACL-reconstructed patients (35 females, 106 males) and 142 controls (37 females, 105 males) from January 2020 to April 2022. Inclusion criteria were primary non-contact ACL injuries. The tibial plateau slope, lateral femoral condyle index, Insall-Salvati index, and patellar tendon angle were measured, using binary logistic regression for gender-specific risk evaluation.ResultsIncreased lateral tibial plateau slope, reduced intercondylar notch width index, lateral femoral condyle index, and patellar tendon angle correlated with ACL injuries in both genders. The Insall-Salvati index was a significant risk factor in females but not in males.ConclusionThis study identifies the lateral tibial plateau slope, notch width index, lateral femoral condyle index, and patellar tendon angle at near-extension as risk factors for ACL injuries in both genders, with the Insall-Salvati index also implicated in females.

Single-Molecule Diffusivity Quantification Unveils Ubiquitous Net Charge-Driven Protein-Protein Interaction.

Recent microscopy and nuclear magnetic resonance (NMR) studies have noticed substantial suppression of intracellular diffusion for positively charged proteins, suggesting an overlooked role of electrostatic attraction in nonspecific protein interactions in a predominantly negatively charged intracellular environment. Utilizing single-molecule detection and statistics, here, we quantify in aqueous solutions how protein diffusion, in the limit of low diffuser concentration to avoid aggregate/coacervate formation, is modulated by differently charged interactor proteins over wide concentration ranges. We thus report substantially suppressed diffusion when oppositely charged interactors are added at parts per million levels, yet unvaried diffusivities when same-charge interactors are added beyond 1%. The electrostatic attraction-driven suppression of diffusion is sensitive to the protein net charge states, as probed by varying the solution pH and ionic strength or chemically modifying the proteins and is robust across different diffuser-interactor pairs. By converting the measured diffusivities to diffuser diameters, we further show that in the limit of excess interactors, a positively charged diffuser molecule effectively drags along just one monolayer of negatively charged interactors, where further interactions stop. We thus unveil ubiquitous, net charge-driven protein-protein interactions and shed new light on the mechanism of charge-based diffusion suppression in living cells.

Tricuspid regurgitation in pulmonary arterial hypertension: a right ventricular volumetric and functional analysis.

The consequences of tricuspid regurgitation (TR) for right ventricular (RV) function and prognosis in pulmonary arterial hypertension (PAH) are poorly described and effects of tricuspid valve repair on the RV are difficult to predict. In 92 PAH patients with available cardiac magnetic resonance (CMR) studies, TR volume was calculated as the difference between RV stroke volume and forward stroke volume, i.e. pulmonary artery (PA) stroke volume. Survival was estimated from the time of the CMR scan to cardiopulmonary death or lung transplantation. In a subgroup, pressure-volume loop analysis including two-parallel elastances was applied to evaluate effective elastances, including net afterload (effective arterial elastance (E a)), forward afterload (effective pulmonary arterial elastance (E pa)) and backward afterload (effective tricuspid regurgitant elastance (E TR)). The effects of tricuspid valve repair were simulated using the online software package Harvi. 26% of PAH patients had a TR volume ≥30 mL. Greater TR volume was associated with increased N-terminal pro-brain natriuretic peptide (p=0.018), mean right atrial pressure (p<0.001) and RV end-systolic and -diastolic volume (both p<0.001). TR volume ≥30 mL was associated with a poor event-free survival (p=0.008). In comparison to E a, E pa correlated better with indices of RV dysfunction. Lower end-systolic elastance (E es) (p=0.002) and E TR (p=0.030), higher E pa (p=0.001) and reduced E es/E pa (p<0.001) were found in patients with a greater TR volume. Simulations predicted that tricuspid valve repair increases RV myocardial oxygen consumption in PAH patients with severe TR and low E es unless aggressive volume reduction is accomplished. In PAH, TR has prognostic significance and is associated with low RV contractility and RV-PA uncoupling. However, haemodynamic simulations showed detrimental consequences of tricuspid valve repair in PAH patients with low RV contractility.

Microwave heterostructures in the form of submicron Y&lt;sub&gt;3&lt;/sub&gt;Fe&lt;sub&gt;5&lt;/sub&gt;O&lt;sub&gt;12&lt;/sub&gt; films on non-oriented ferroelectric ceramic substrates: synthesis, properties, and prospects for applications

In the work monolithic structures of yttrium iron garnet (YIG, Y3Fe5O12) with a thickness of about 2 μm were obtained on ferroelectric ceramic substrates based on PbZr0.45Ti0.55O3 (PZT) and Ba0.4Sr0.6TiO3 (BST). The Y3Fe5O12 layer was deposited by ion beam sputtering deposition on substrates 400 μm thick by sputtering a polycrystalline Y3Fe5O12 target with with argon ions. The heterostructures were crystallized by annealing in air at a temperature of 820 °C for 5 min. The results of the characteristic X-ray radiation method showed that the elemental composition of the monolithic heterostructure corresponds to the specified one. During X-ray studies, it was found that the YIG crystallization process is completed and the resulting structure is single-phase. The results of magnetic and ferromagnetic resonance studies indicate the possibility of using the obtained heterostructures in logic circuits based on spin waves with low scattering, in memory elements, as well as in electrically controlled microwave devices.

The effect of hyperlipidemia and body fat distribution on subclinical left ventricular function in obesity: a cardiovascular magnetic resonance study

BackgroundObesity is often associated with multiple comorbidities. However, whether obese subjects with hyperlipidemia in the absence of other complications have worse cardiac indices than metabolically healthy obese subjects is unclear. Therefore, we aimed to determine the effect of hyperlipidemia on subclinical left ventricular (LV) function in obesity and to evaluate the association of cardiac parameters with body fat distribution.Materials and methodsNinety-two adults were recruited and divided into 3 groups: obesity with hyperlipidemia (n = 24, 14 males), obesity without hyperlipidemia (n = 25, 13 males), and c ntrols (n = 43, 25 males). LV strain parameters (peak strain (PS), peak diastolic strain rate (PDSR), peak systolic strain rate) derived from cardiovascular magnetic resonance tissue tracking were measured and compared. Dual-energy X-ray absorptiometer was used to measure body fat distribution. Correlations of hyperlipidemia and body fat distribution with LV strain were assessed by multivariable linear regression.ResultsObese individuals with preserved LV ejection fraction showed lower global LV longitudinal, circumferential, and radial PS and longitudinal and circumferential PDSR than controls (all P < 0.05). Among obese patients, those with hyperlipidemia had lower longitudinal PS and PDSR and circumferential PDSR than those without hyperlipidemia (− 12.8 ± 2.9% vs. − 14.2 ± 2.7%, 0.8 ± 0.1 s−1 vs. 0.9 ± 0.3 s−1, 1.2 ± 0.2 s−1 vs. 1.4 ± 0.2 s−1; all P < 0.05). Multivariable linear regression demonstrated that hyperlipidemia was independently associated with circumferential PDSR (β = − 0.477, P < 0.05) in obesity after controlling for growth differences, other cardiovascular risk factors, and central fat distribution. In addition, android fat had an independently negative relationship with longitudinal and radial PS (β = − 0.486 and β = − 0.408, respectively; all P < 0.05); and visceral fat was negatively associated with longitudinal PDSR (β = − 0.563, P < 0.05). Differently, gynoid fat was positively correlated with circumferential PS and PDSR and radial PDSR (β = 0.490, β = 0.481, and β = 0.413, respectively; all P < 0.05).ConclusionHyperlipidemia is independently associated with subclinical LV diastolic dysfunction in obesity. Central fat distribution (android and visceral fat) has a negative association, while peripheral fat distribution (gynoid fat) has a positive association on subclinical LV function. These results suggest that appropriate management of hyperlipidemia may be beneficial for obese patients, and that the differentiation of fat distribution in different regions may facilitate the precise management of obese patients.Clinical trials registration Effect of lifestyle intervention on metabolism of obese patients based on smart phone software (ChiCTR1900026476).

Protocolo diagnóstico de las lesiones sólidas pancreáticas

Most solid lesions that appear in the pancreas are usually malignant in nature. Ductal adenocarcinoma is the most common, followed by neuroendocrine tumors. Computed tomography (CT) is the radiological test of choice, as it provides information on both the nature of the lesion and its extension. Magnetic resonance studies also have a good diagnostic performance. An endoscopic ultrasound is the test of choice for biopsies, as it will provide a definitive diagnosis and, in addition, has better resolution than a CT scan for small lesions. Solid lesions that appear in the context of chronic pancreatitis or autoimmune pancreatitis may be benign in nature, although both entities entail a higher risk of developing pancreatic tumors. Therefore, the differential diagnosis should be comprehensive.

A Radioanatomical Evaluation of the Plantaris Tendon with Magnetic Resonance Imaging Method and a Review of the Literature in the Light of Our Findings

Introduction: Variations of the plantaris muscle and tendon are common. Ultrasonography and magnetic resonance imaging (MRI) are radiological methods for evaluating the plantaris tendon. This study aimed to perform a radioanatomical evaluation of the plantar tendon using MRI and to compare our findings with the literature data. Materials and Methods: The presence of the plantaris tendon in 155 ankle magnetic resonance studies of 139 patients, its diameter, its course, the localization of the calcaneal attachment of the tendon, and its relationship with the Achilles tendon were evaluated. Student’s t-test was used for those with normal distribution in numerical data, and the Mann–Whitney U test was used for those who did not. Pearson Chi-square test was used in the evaluation of categorical data, depending on the assumptions. P &lt;0.05 was considered statistically significant. Results: A total of 139 patients, 89 (67.74%) females, and 50 (32.26%) males were included in the study. In 115 (74.2%) of 142 cases in which the plantaris tendon was imaged, the plantaris tendon was inserted into the calcaneus separately from the Achilles tendon and was joining the Achilles tendon at various levels in 27 cases (17.41%). In 27 cases where the plantaris tendon joined with the Achilles tendon, the distance from the junction point to the calcaneal insertion was 15 ± 9.90 cm. Conclusion: Our study is one of the limited number of studies in the literature to examine the thickness and termination levels of the plantaris tendon. We believe that our measurements will contribute to future radioanatomical meta-analyses.

Neural correlates of musical familiarity: a functional magnetic resonance study.

Existing neuroimaging studies on neural correlates of musical familiarity often employ a familiar vs. unfamiliar contrast analysis. This singular analytical approach reveals associations between explicit musical memory and musical familiarity. However, is the neural activity associated with musical familiarity solely related to explicit musical memory, or could it also be related to implicit musical memory? To address this, we presented 130 song excerpts of varying familiarity to 21 participants. While acquiring their brain activity using functional magnetic resonance imaging (fMRI), we asked the participants to rate the familiarity of each song on a five-point scale. To comprehensively analyze the neural correlates of musical familiarity, we examined it from four perspectives: the intensity of local neural activity, patterns of local neural activity, global neural activity patterns, and functional connectivity. The results from these four approaches were consistent and revealed that musical familiarity is related to the activity of both explicit and implicit musical memory networks. Our findings suggest that: (1) musical familiarity is also associated with implicit musical memory, and (2) there is a cooperative and competitive interaction between the two types of musical memory in the perception of music.

Enhanced Myocardial Tissue Visualization: A Comparative Cardiovascular Magnetic Resonance Study of Gradient-Spin Echo-STIR and Conventional STIR Imaging.

This study is aimed at evaluating the efficacy of the gradient-spin echo- (GraSE-) based short tau inversion recovery (STIR) sequence (GraSE-STIR) in cardiovascular magnetic resonance (CMR) imaging compared to the conventional turbo spin echo- (TSE-) based STIR sequence, specifically focusing on image quality, specific absorption rate (SAR), and image acquisition time. In a prospective study, we examined forty-four normal volunteers and seventeen patients referred for CMR imaging using conventional STIR and GraSE-STIR techniques. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), image quality, T2 signal intensity (SI) ratio, SAR, and image acquisition time were compared between both sequences. GraSE-STIR showed significant improvements in image quality (4.15 ± 0.8 vs. 3.34 ± 0.9, p = 0.024) and cardiac motion artifact reduction (7 vs. 18 out of 53, p = 0.038) compared to conventional STIR. Furthermore, the acquisition time (27.17 ± 3.53 vs. 36.9 ± 4.08 seconds, p = 0.041) and the local torso SAR (<13% vs. <17%, p = 0.047) were significantly lower for GraSE-STIR compared to conventional STIR in short-axis plan. However, no significant differences were shown in T2 SI ratio (p = 0.141), SNR (p = 0.093), CNR (p = 0.068), and SAR (p = 0.071) between these two sequences. GraSE-STIR offers notable advantages over conventional STIR sequence, with improved image quality, reduced motion artifacts, and shorter acquisition times. These findings highlight the potential of GraSE-STIR as a valuable technique for routine clinical CMR imaging.