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Background: Myocardial hypoxia has been demonstrated in many cardiomyopathies and is related to development of myocardial fibrosis. However, myocardial hypoxia and its association with myocardial fibrosis are understudied in Duchenne muscular dystrophy (DMD)-associated cardiomyopathy., Purpose: To evaluate myocardial hypoxia by oxygenation-sensitive (OS) cardiac magnetic resonance imaging, and further explore its association with fibrosis., Study Type: Prospective., Subjects: Ninety-one DMD boys (8.78 ± 2.32) and 30 healthy boys (9.07 ± 2.30)., Field Strength/sequence: 3 T, Balanced steady-state free procession, Modified Look-Locker inversion recovery sequence and Single-shot phase-sensitive inversion recovery sequence., Assessment: Cardiac MRI data, including left ventricular functional, segmental native T1, and oxygenation signal-intensity (SI) according to AHA 17-segment model, were acquired. Patients were divided into LGE+ and LGE- groups. In patients with LGE, all segments were further classified as positive or negative segments by segmentally presence/absence of LGE., Statistical Tests: Variables were compared using Student's t, Wilcoxon, Kruskal-Wallis test and one-way analysis of variance. Bivariate Pearson or Spearman correlation were calculated to determine association between oxygenation SI and native T1. Variables with P < 0.10 in the univariable analysis were included in multivariable model. Receiver operating characteristic analysis was used to assess the performance of OS in diagnosing myocardial hypoxia., Results: The myocardial oxygenation SI of DMD was significantly decreased in all segments compared with normal controls, and more obvious in the LGE+ segments (0.46 ± 0.03 vs. 0.52 ± 0.03). For patients with and without LGE, myocardial oxygenation SI were significantly negatively correlated with native T1 in all segments (r = -0.23 to -0.42). The inferolateral oxygenation SI was a significant independent associator of LGE presence (adjusted OR = 0.900)., Data Conclusion: Myocardial hypoxia evaluated by the OS-Cardiac-MRI indeed occurs in DMD and associate with myocardial fibrosis, which might be used as a biomarker in assessing myocardial damage in DMD., Evidence Level: 1 TECHNICAL EFFICACY: Stage 1., (© 2024 International Society for Magnetic Resonance in Medicine.)

Objective: The aim of this study is to explore the practical value of prenatal magnetic resonance imaging (MRI) in the assessment of congenital cystic lung disease in fetuses, to evaluate the relative size of the lesion and the status of lung development, and to make an attempt at utilizing the strength of MRI in post-processing to obtain assessment indicators of the size of the lesion and the status of lung development, with which predictions can be made for the prognosis that these fetuses may face after birth. We retrospectively collected and analyzed the data of fetuses diagnosed with congenital cystic lung disease. Prenatal ultrasound examination of these fetuses led to the diagnosis that they were suspected of having congenital cystic lung disease and the diagnosis was confirmed by subsequent prenatal MRI. The fetuses were followed up to track their condition at birth (postnatal respiratory distress, mechanical ventilation, etc.), whether the fetuses underwent surgical treatment, and the recovery of the fetuses after surgical treatment. The recovery of the fetuses was followed up to explore the feasibility of prenatal MRI examination to assess fetal congenital pulmonary cystic disease, and to preliminarily explore the predictive value of prenatal MRI for the prognosis of fetuses with congenital pulmonary cystic disease., Methods: MRI fetal images were collected from pregnant women who attended the West China Second University Hospital of Sichuan University between May 2018 and March 2023 and who were diagnosed with fetal congenital pulmonary cystic disease by prenatal ultrasound and subsequent MRI. Fetal MRI images of congenital cystic lung disease were post-processed to obtain the fetal lung lesion volume, the fetal affected lung volume, the healthy lung volume, and the fetal head circumference measurements. The signal intensity of both lungs and livers, the lesion volume/the affected lung volume, the lesion volume/total lung volume, the cystic volume ratio (CVR), and the bilateral lung-liver signal intensity ratio were measured. The feasibility and value of MRI post-processing acquisition indexes for evaluating the prognosis of fetuses with congenital cystic lung disease were further analyzed by combining the follow-up results obtained 6 months after the birth of the fetus. Logistic regression models were used to quantify the differences in maternal age, gestational week at the time of MRI, CVR, and bilateral lung-to-liver signal intensity ratio, and to assess whether these metrics correlate with poor prognosis. Receiver operating characteristic (ROC) curves were used to assess the value of the parameters obtained by MRI calculations alone and in combination with multiple metrics for predicting poor prognosis after birth., Results: We collected a total of 67 cases of fetuses diagnosed with congenital cystic lung disease by fetal MRI between May 2018 and March 2023, and excluded 6 cases with no normal lung tissue in the affected lungs, 11 cases of fetal induction, and 3 cases of loss of pregnancy. In the end, 47 cases of fetuses with congenital cystic lung disease were included, of which 30 cases had a good prognosis and 17 cases had a poor prognosis. The difference in the difference between the signal intensity ratios of the affected and healthy sides of the lungs and livers of the fetuses in the good prognosis group and that in the poor prognosis group was statistically significant ( P <0.05), and the signal intensity ratio of the healthy side of the lungs and livers was higher than the signal intensity ratio of the affected side of the lungs and livers. Further analysis showed that CVR (odds ratio [OR]=1.058, 95% confidence interval [CI]: 1.014-1.104), and the difference between the lung-to-liver signal intensity ratios of the affected and healthy sides (OR=0.814, 95% CI: 0.700-0.947) were correlated with poor prognosis of birth in fetuses with congenital cystic lung disease. In addition, ROC curve analysis showed that the combined application of lesion volume/affected lung volume and the observed difference in the signal intensity ratio between the affected and healthy lungs and liver predicted the prognosis of children with congenital cystic lung disease more accurately than the single-parameter judgment did, with the area under the curve being 0.988, and the cut-off value being 0.33, which corresponded to a sensitivity of 100%, a specificity of 93.3%, and a 95% CI of 0.966-1.000., Conclusions: Based on the MRI of fetuses with congenital cystic lung disease, we obtained information on lesion volume, lesion volume/affected lung volume, lesion volume/total lung volume, CVR, and bilateral lung-to-liver signal intensity ratio difference, all of which showing some clinical value in predicting the poor prognosis in fetuses with congenital cystic lung disease. Furthermore, among the combined indexes, the lesion volume/affected lung volume and bilateral lung-to-liver signal intensity ratio difference are more effective predictors for the poor prognosis of fetuses with congenital cystic lung disease, and show better efficacy in predicting the poor prognosis of fetuses with congenital cystic lung disease. This provides a new and effective predictive method for further assessment of pulmonary lung development in fetuses with congenital cystic lung disease, and helps improve the assessment and prediction of the prognosis of fetuses with congenital cystic lung disease., Competing Interests: 利益冲突　本文作者郭应坤是本刊编委会编委。该文在编辑评审过程中所有流程严格按照期刊政策进行，且未经其本人经手处理。除此之外，所有作者均声明不存在利益冲突。, (© 2024《四川大学学报（医学版）》编辑部 版权所有Copyright ©2024 Editorial Office of Journal of Sichuan University (Medical Sciences).)

Purpose: To assess right ventricular (RV) dysfunction in end-stage renal disease (ESRD) patients on maintenance haemodialysis (HD) by cardiac magnetic resonance (CMR) imaging and determined the risk factors associated with RV dysfunction., Materials and Methods: Fifty ESRD patients on maintenance HD and 16 age- and gender-matched healthy individuals were prospectively enrolled and underwent CMR imaging. Left ventricular (LV) and RV function parameters, including end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF), were measured and compared. Independent sample t-test and Mann-Whitney U-test were used to compare the differences between healthy individuals and ESRD patients. Pearson correlation and multiple linear regression analyses were used to assess risk factors associated with RV dysfunction., Results: Significantly lower RVEF and LVEF were observed in ESRD patients than in the control group (all p < 0.001). RVEDV, RVESV and RVSV in ESRD patients were also lower than those in the control group (all p < 0.05). Meanwhile, higher LVESV, LV mass and interventricular septum thickness were found in ESRD patients than in the control group (all p < 0.05). RVEF was positively correlated with LVEF (r = 0.37, p = 0.008) and negatively correlated with the duration of renal insufficiency (r = -0.53, p < 0.001) and dialysis (r = -0.63, p < 0.001). Moreover, multiple linear regression analyses revealed that the duration of dialysis and LVEF were independently associated with decreased RVEF (adjusted R 2  = 0.53, p < 0.001)., Conclusions: In ESRD patients on maintenance HD, RV function was impaired and associated with the deterioration of LV function. More importantly, the duration of dialysis was considered as a risk factor independently associated with RV dysfunction., (Copyright © 2018. Published by Elsevier B.V.)

Clinically, myocardial fibrosis is increasingly being recognized as a new therapeutic target for ischaemic heart diseases. The aim of this study was to investigate whether noninvasive multimodal molecular imaging could be used to dynamically assess whether the combination of bone marrow mesenchymal stem cells (BMSCs) and hepatocyte growth factor (HGF) therapy can synergistically attenuate myocardial fibrosis after myocardial infarction (MI). MI was induced in 28 rats by coronary ligation with subsequent injection of BMSCs/HGF, BMSCs, HGF, or saline into the border zone under echocardiography guidance. The therapeutic procedure and treatment effects were tracked and assessed using bioluminescence imaging (BLI) and cardiac magnetic resonance (MR) imaging. Four weeks after transplantation therapy, cardiac MR imaging demonstrated that BMSC/HGF-treated animals showed better ejection fractions (p < 0.001) and smaller scar sizes (p < 0.001) than those treated with BMSCs or HGF alone. Histopathological and immunohistochemical results showed less collagen deposition, increased microvessel densities and more regenerative cardiomyocytes in the BMSC/HGF-treated animals than in those receiving HGF or BMSCs alone (all p < 0.05). Multimodal molecular imaging allows a specific and timely strategy to be established for dynamically tracking treatment and noninvasively assessing the therapeutic effects. Under echocardiography guidance, intramyocardial injection of transfected HGF with BMSCs can enhance cell survival, improve cardiac function, stimulate angiogenesis, and reduce myocardial fibrosis in a post-MI rat model.

pH-sensitive amide proton transfer (APT) MRI provides a surrogate metabolic biomarker that complements the widely-used perfusion and diffusion imaging. However, the endogenous APT MRI is often calculated using the asymmetry analysis (MTRasym), which is susceptible to an inhomogeneous shift due to concomitant semisolid magnetization transfer (MT) and nuclear overhauser (NOE) effects. Although the intact brain tissue has little pH variation, white and gray matter appears distinct in the MTRasym image. Herein we showed that the heterogeneous MTRasym shift not related to pH highly correlates with MT ratio (MTR) and longitudinal relaxation rate (R1w), which can be reasonably corrected using the multiple regression analysis. Because there are relatively small MT and R1w changes during acute stroke, we postulate that magnetization transfer and relaxation-normalized APT (MRAPT) analysis increases MRI specificity to acidosis over the routine MTRasym image, hence facilitates ischemic lesion segmentation. We found significant differences in perfusion, pH and diffusion lesion volumes (P<0.001, ANOVA). Furthermore, MRAPT MRI depicted graded ischemic acidosis, with the most severe acidosis in the diffusion lesion (-1.05±0.29%/s), moderate acidification within the pH/diffusion mismatch (i.e., metabolic penumbra, -0.67±0.27%/s) and little pH change in the perfusion/pH mismatch (i.e., benign oligemia, -0.04±0.14%/s), providing refined stratification of ischemic tissue injury., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Dilated cardiomyopathy(DCM)is a highly prevalent disease which has multiple clinical manifestations and pathological features.With the characteristics of multi-sequence and multi-parameter,cardiac magnetic resonance imaging(MRI)can accurately assess the morphology,function and tissue characterization of heart,and provide comprehensive information for diagnosis of DCM.This review focuses on the sequences and clinical applications of MRI evaluation in DCM in order to provide additional information for clinical diagnosis,treatment and prognosis.

Chemical exchange saturation transfer (CEST) MRI holds enormous promise for imaging pH. Whereas the routine CEST-weighted MRI contrast is complex and susceptible to confounding factors such as labile proton ratio, chemical shift, bulk water relaxation and RF saturation, ratiometric CEST imaging simplifies pH determination. However, the conventional ratiometric CEST (RCEST) MRI approach is limited to CEST agents with multiple exchangeable groups. To address this limitation, RF power-based ratiometric CEST (PRCEST) imaging has been proposed that ratios CEST effects obtained under different RF power levels. Nevertheless, due to concomitant RF saturation (spillover) effect, the recently proposed PRCEST imaging is somewhat dependent on parameters including bulk water relaxation time and chemical shift. Herein we hypothesized that RF power-based ratiometric analysis of RF spillover effect-corrected inverse CEST asymmetry (PRICEST) provides enhanced pH measurement. The postulation was verified numerically, and validated experimentally using an in vitro phantom. Briefly, our study showed that the difference between MRI-determined pH (pHMRI ) and electrode-measured pH being 0.12 ± 0.13 and 0.04 ± 0.03 for PRCEST and PRICEST imaging, respectively, and the newly proposed PRICEST imaging provides significantly more accurate pH determination than PRCEST imaging (P < 0.01, Wilcoxon signed-rank test). Notably, the exchange rate shows dominantly base-catalysed relationship with pH, independent of creatine concentration (P > 0.10, Analysis of Covariance). In addition, the derived labile proton ratio linearly scales with creatine concentration (P < 0.01, Pearson Regression). To summarize, PRICEST MRI provides concentration-independent pH imaging, augmenting prior quantitative CEST methods for accurate pH mapping. Copyright © 2015 John Wiley & Sons, Ltd., (Copyright © 2015 John Wiley & Sons, Ltd.)

Chemical exchange saturation transfer (CEST) MRI is a versatile imaging method that probes the chemical exchange between bulk water and exchangeable protons. CEST imaging indirectly detects dilute labile protons via bulk water signal changes following selective saturation of exchangeable protons, which offers substantial sensitivity enhancement and has sparked numerous biomedical applications. Over the past decade, CEST imaging techniques have rapidly evolved owing to contributions from multiple domains, including the development of CEST mathematical models, innovative contrast agent designs, sensitive data acquisition schemes, efficient field inhomogeneity correction algorithms, and quantitative CEST (qCEST) analysis. The CEST system that underlies the apparent CEST-weighted effect, however, is complex. The experimentally measurable CEST effect depends not only on parameters such as CEST agent concentration, pH and temperature, but also on relaxation rate, magnetic field strength and more importantly, experimental parameters including repetition time, RF irradiation amplitude and scheme, and image readout. Thorough understanding of the underlying CEST system using qCEST analysis may augment the diagnostic capability of conventional imaging. In this review, we provide a concise explanation of CEST acquisition methods and processing algorithms, including their advantages and limitations, for optimization and quantification of CEST MRI experiments., (Copyright © 2015 John Wiley & Sons, Ltd.)

This study is designed to test the agreement in measuring left ventricular systolic function between transthoracic two-dimensional echocardiography (2DTTE) and "gold standard" of non-invasive cardiac imaging, magnetic resonance imaging (CMRI) and their impacts on the classification of patients according to the left ventricular ejection fraction (EF). 32 patients who were suspected with heart disease were evaluated by CMRI and 2DTTE examinations. End diastolic volume (EDV), end systolic volume (ESV), EF and left ventricular function category were then calculated and compared. There was no significant difference (P=0.504) for EDV, while ESV of CMRI was significantly higher than that of 2DTTE (P=0.049), and EF of CMRI was significantly lower than that of 2DTTE (P= 0.018). There was no significant difference (P=0.077) in left ventricular functional category. Bland-Altman analysis of LV volumetric data and EF measurements showed a good agreement between two methods. The 2DTTE over-estimated I (n=5) or II (n=1) degrees of functional classification when compared with the CMRI. Both CMRI and 2DTTE are of great clinical value in evaluating left ventricular systolic function, while CMR may be more beneficial to patients with abnormal LV functions.

To elucidate the MR urography (MRU) features of ectopic ureter orifice in children and to explicate its advantages, the clinical data and MRU findings of 4 cases with ectopic ureter orifice were analyzed retrospectively. Among the 4 cases of ectopic ureter orifice, 2 were associated with dysplasia of kidneys, 1 was associated with duplex kidney, and the remaining 1 was associated with cross ectopic and dyplasia kidney. When combining the MRI and MRU examination, we could diagnose the ectopic orifice of the draining ureters. So we concluded that definitive diagnosis could be achieved in most of the cases by integrating clinical information with MRU findings.

Objective: Turner syndrome (TS) has an increased predisposition to ischaemic heart disease and the status of coronary microcirculation in TS is largely unknown. This study aims to evaluate myocardial microvascular function in TS using first‐pass magnetic resonance perfusion imaging and determine significant risk factors contributing to microvascular dysfunction in the early stage. Design: Perspective cohort study. Patients: The study cohort consisted of 67 children and youth with TS and 32 age‐ and gender‐matched controls. Measurements Clinical characteristics, left ventricle (LV) volume and function and cardiovascular magnetic resonance‐derived myocardial perfusion parameters were assessed. Univariable and multivariable linear regression analyses were performed to assess the potential risk factors for microvascular dysfunction. Result: Microvascular perfusion decreased in TS in global and segmented myocardium as reflected in the lower upslopecor and maximum signal intensity (MaxSI) of LV myocardium compared to controls. Multivariable linear regression analysis indicated that age (β = −0.107, 95% confidence interval [CI] = −0.201 to −0.013, p =.026) and being overweight/obese (β = −1.155, CI = −2.134 to −0.176, p =.021) were independent impact factors of microvascular dysfunction. Subgroup analysis showed the upslopecor of older patients with TS decreased more significantly compared with that of normal controls. Upslopecor and MaxSI were lower in overweight/obese patients with TS than in patients with normal body mass index (BMI) and controls. Conclusion: Myocardial microvascular dysfunction can occur in children and youth patients with TS. Age and overweight/obesity were the independent risk factors of microvascular dysfunction, which imply the importance of lowering BMI for the prevention of coronary heart disease in young TS population. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) are closely associated with the progression of diabetic cardiomyopathy (DCM) and can be regarded as one of its early biomarkers. Magnetic resonance imaging (MRI) is emerging as a powerful tool for the detection of cardiac abnormalities, but the sensitive and direct ROS-response MRI probe remains to be developed. This restricts the early diagnosis of DCM and prevents timely clinical interventions, resulting in serious and irreversible pathophysiological abnormalities. Herein, a novel ROS-response contrast-enhanced MRI nanoprobe (RCMN) is developed by multi-functionalizing fluorinated carbon nanosheets (FCNs) with multi-hydroxyl and 2,2,6,6-tetramethylpiperidin-1-oxyl groups. RCMNs capture ROS and then gather in the heart provisionally, which triggers MRI signal changes to realize the in vivo detection of ROS. In contrast to the clinical MRI agents, the cardiac abnormalities of disease mice is detected 8 weeks in advance with the assistance of RCMNs, which greatly advances the diagnostic window of DCM. To the best of the knowledge, this is the first ROS-response metal-free T2-weighted MRI probe forthe early diagnosis of DCM mice model. Furthermore, RCMNs can timely scavenge excessively produced ROS to alleviate oxidative stress. [ABSTRACT FROM AUTHOR]

Objective: To describe the disease progression of Duchenne muscular dystrophy (DMD) in the pelvic and thigh muscles over 1-year using multiple-parameter quantitative magnetic resonance imaging (qMRI), and to determine the most responsive muscle and predict subclinical disease progression in functionally stable patients. Methods: Fifty-four DMD patients (mean age 8.9 ± 2.5, range 5–15 years) completed baseline and 1-year follow-up qMRI examinations/biomarkers [3-point Dixon/fat fraction (FF); T1 mapping/T1; T2 mapping/T2]. Meanwhile, clinical assessments [NorthStar ambulatory assessment (NSAA) score] and timed function tests were performed in DMD patients. Twenty-four healthy male controls (range 5–15 years) accomplished baseline qMRI examinations. Group differences were compared using the Wilcoxon test. The standardized response mean (SRM) was taken as the responsiveness to the disease progression index. Results: FF, T1, and T2 in all DMD age subgroups changed significantly over 1-year (P < 0.05). Even in functionally stable patients (NSAA score increased, unchanged, or decreased by 1-point) over 1-year, significant increases in FF and T2 and decreases in T1 were observed in gluteus maximus (GMa), gluteus medius, vastus lateralis, and adductor magnus (P < 0.05). Overall, the SRM of FF, T1, and T2 was all the highest in GMa, which were 1.25, − 0.92, and 0.93, respectively. Conclusions: qMRI biomarkers are responsive to disease progression and can also detect subclinical disease progression in functionally stable DMD patients over 1-year. GMa is the most responsive to disease progression of all the muscles analyzed. Trial registration: Chinese Clinical Trial Registry (http://www.chictr.org.cn/index.aspx) ChiCTR1800018340, 09/12/2018, prospectively registered. [ABSTRACT FROM AUTHOR]

Endothelia progenitor cell (EPC)-based revascularization therapies have shown promise for the treatment of myocardial ischemic injury. However, applications and efficacy are limited by the relatively inefficient recruitment of endogenous EPCs to the ischemic area, while implantation of exogenous EPCs carries the risk of tumorigenicity. In this study, we developed a therapeutic protocol that relies on the capacity of neutrophils (NEs) to target lesions and release preloaded EPC-binding molecules for high efficiency capture. Neutrophils were loaded with superparamagnetic iron oxide nanoparticles conjugated to an antibody against the EPC surface marker CD34 (SPIO-antiCD34/NEs), and the therapeutic efficacy in ischemic mouse heart following SPIO-antiCD34/NEs injection was monitored by SPIO-enhanced magnetic resonance imaging (MRI). These SPIO-antiCD34/NEs exhibited unimpaired cell viability, superoxide generation, and chemotaxis in vitro as well as satisfactory biocompatibility in vivo. In a mouse model of acute myocardial infarction (MI), SPIO-antiCD34 accumulation could be observed 0.5 h after intravenous injection of SPIO-antiCD34/NEs. Moreover, the degree of CD133+ EPC accumulation at MI sites was three-fold higher than in control MI model mice, while ensuing microvessel density was roughly two-fold higher than controls and left ventricular ejection fraction was > 50%. Therapeutic cell biodistribution, MI site targeting, and treatment effects were confirmed by SPIO-enhanced MRI. This study offers a new strategy to improve the endogenous EPC-based myocardial ischemic injury repair through NEs mediated SPIO nanoparticle conjugated CD34 antibody delivery and imaging. The efficacy of endogenous endothelial progenitor cell (EPC)-based cardiovascular repair therapy for ischemic heart damage is limited by relatively low EPC accumulation at the target site. We have developed a method to improve EPC capture by exploiting the strong targeting ability of neutrophils (NEs) to ischemic inflammatory foci and the capacity of these treated cells to release of preloaded cargo with EPC-binding affinity. Briefly, NEs were loaded with superparamagnetic iron oxide nanoparticles conjugated to an antibody against the EPC surface protein CD34 (SPIO-antiCD34). Thus, we explored sites targeting with nanocomposites cargo for non-invasive EPCs interception and therapy tracking. We demonstrate that SPIO-antiCD34 released from NEs can effectively capture endogenous EPCs and thereby promote heart revascularization and functional recovery in mice. Moreover, the entire process can be monitored by SPIO-enhanced magnetic resonance imaging including therapeutic cell biodistribution, myocardial infarction site targeting, and tissue repair. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Secondary hyperparathyroidism is a common complication of end-stage renal disease (ESRD), which may be associated with cardiovascular diseases. Thus, this study aimed to explore myocardial damage using non-contrast cardiovascular magnetic resonance (CMR) in ESRD patients undergoing hemodialysis and further investigate its relationship with parathyroid hormone (PTH) toxicity. Methods: Seventy-two adult ESRD patients receiving regular hemodialysis and 30 healthy subjects underwent CMR examination. Continuous CMR cine sections from the mitral valve level to the left ventricular (LV) apex in the short-axis plane, cine series of vertical two-chamber long-axis plane, and horizontal four-chamber plane were acquired. Native T1 mapping was obtained using modified Look-Locker inversion recovery (MOLLI) sequences. Native T1 values and myocardial strain were analyzed. Immunoreactive parathyroid hormone (iPTH) was obtained from all enrolled patients. Results: Forty (55.6%) hemodialysis ESRD patients were found to have increased iPTH levels. LV ejection fraction (LVEF) of both ESRD patients with targeted and increased iPTH levels was decreased compared with healthy subjects (55.9 ± 12.0% vs. 65.0 ± 4.5%; 51.7 ± 12.8 vs. 65.0 ± 4.5%, both P < 0.05). The mean peak radial strain (PRS), peak circumferential strain (PCS), and peak longitudinal strain (PLS) were lowest in ESRD patients with increased iPTH; however, no significant difference was observed among these three groups. Segmentally, from base to apex, the native T1 of ESRD patients with increased iPTH levels tended to be higher than those with targeted iPTH and healthy subjects (all P < 0.05). In ESRD patients with targeted iPTH, both native T1 of basal and middle segments were significantly higher than normal subjects (basal, 1304 ± 41 ms vs. 1238 ± 36 ms, P = 0.001; middle, 1300 ± 43 ms vs. 1242 ± 50 ms, P < 0.001). Comparing global native T1 values in the three groups, ESRD patients with targeted and increased iPTH level showed increased native T1 (1305 ± 41 ms vs. 1251 ± 49 ms, P = 0.001; 1334 ± 40 ms vs. 1251 ± 49 ms, P < 0.001, respectively). Native T1 values of the basal segment and global native T1 were moderately associated with iPTH (r = 0.4, P < 0.001; r = 0.5, P < 0.001). Multiple linear regression analysis showed that global native T1 values (beta = 1.0, P = 0.01) were independently associated with iPTH. Conclusions: Elevated iPTH level was associated with and was an independent risk factor for myocardial damage in ESRD patients undergoing maintenance hemodialysis. Trial registration: Chinese Clinical Trial Registry (http://www.chictr.org.cn/index.aspx) ChiCTR-DND-17012976, 13/12/2017, retrospectively registered. [ABSTRACT FROM AUTHOR]

Cell labeling and tracking via magnetic resonance imaging (MRI) has drawn much attention for its noninvasive property and longitudinal monitoring functionality. Employing of imaging probes with high labeling efficiency and good biocompatibility is one of the essential factors that determine the outcome of tracking. In this study, negatively charged superparamagnetic iron oxide (PAsp-PCL/SPIO) nanoclusters are developed for dendritic cell (DC) labeling and tracking in vivo. PAsp-PCL/SPIO has a diameter of 124 ± 41 nm in DLS, negatively charged surface (zeta potential = −27 mV), and presents high T2 relaxivity (335.6 Fe m m−1 s−1) and good DC labeling efficiency. Labeled DCs are unaffected in their viability, proliferation, and differentiation capacity, and have an excellent MR imaging sensitivity in vitro. To monitor the migration of DCs into lymphoid tissues in vivo, which will be related to the final immunotherapy results, T2-wighted and T2-map imaging of popliteal nodes at different points in time are acquired under a clinical 3 T scanner after subcutaneous injection of a certain number of labeled DCs at hindleg footpads of mice. The signal intensities decreasing and T2 values shortening of ipsilateral popliteal nodes are significant and display a time- and dose-dependence, showing DCs' migration to the draining lymph nodes. [ABSTRACT FROM AUTHOR]

Automatic and accurate segmentation of the whole heart structure from 3D cardiac images plays an important role in helping physicians diagnose and treat cardiovascular disease. However, the time-consuming and laborious manual labeling of the heart images results in the inefficiency of utilizing the existing CT or MRI for training the deep learning network, which decrease the accuracy of whole heart segmentation. However, multi-modality data contains multi-level information of cardiac images due to different imaging mechanisms, which is beneficial to improve the segmentation accuracy. Therefore, this paper proposes a cascaded framework with cross-modality transfer learning for whole heart segmentation (CM-TranCaF), which consists of three key modules: modality transfer network (MTN), U-shaped multi-attention network (MAUNet) and spatial configuration network (SCN). In MTN, MRI images are transferred from MRI domain to CT domain, to increase the data volume by adopting the idea of adversarial training. The MAUNet is designed based on UNet, while the attention gates (AGs) are integrated into the skip connection to reduce the weight of background pixels. Moreover, to solve the problem of boundary blur, the position attention block (PAB) is also integrated into the bottom layer to aggregate similar features. Finally, the SCN is used to finetune the segmentation results by utilizing the anatomical information between different cardiac substructures. By evaluating the proposed method on the dataset of the MM-WHS challenge, CM-TranCaF achieves a Dice score of 91.1% on the testing dataset. The extensive experimental results prove the effectiveness of the proposed method compared to other state-of-the-art methods. [Display omitted] • The CM-TranCaF framework improves heart segmentation, transferring MRI to CT while preserving heart shape using the MTN module. MAUNet addresses class imbalances and boundary clarity, and SCN module uses spatial relations to boost segmentation accuracy. Achieving a 91.1% Dice score and a 14.386 mm Hausdorff Distance on the MM-WHS dataset, our method demonstrates competitive performance against other techniques. [ABSTRACT FROM AUTHOR]

Background: Antenatal depression (ATDP) is one of the most common mental disorders that occur during the antenatal period. As a serious problem in households around the world, ATDP has adverse consequences for both mothers and offspring and heavily burdens their families and society. However, until recently, the neurobiological mechanisms underlying ATDP remained unclear, which impeded early detection and intervention for this disorder.Methods: To explore the intrinsic cerebral activity alternations in ATDP, we investigated fractional amplitude of low-frequency fluctuation (fALFF) differences in 20 treatment-naïve ATDP patients and 22 healthy pregnant women (HPW) using voxel-based whole-brain analysis by resting-state functional magnetic resonance imaging. The correlation between the regional functional abnormalities and clinical variables in ATDP patients was also examined.Results: Compared with HPW, ATDP patients showed increased fALFF in the left medial prefrontal cortex, dorsolateral prefrontal cortex and anterior cingulate cortex, as well as decreased fALFF in the bilateral orbitofrontal cortex, the right insula, the cluster covering the right ventral temporal cortex (VTC) and the parahippocampus (PHP). The Edinburgh Postnatal Depression Scale scores of ATDP patients were negatively correlated with fALFF values in the right VTC and PHP.Limitations: The study is limited by a small sample size and the fact that only antenatal maternal women in the second and third trimesters were assessed.Conclusion: The aberrant regional functional activities of ATDP patients were mainly located within the prefrontal-limbic circuit related to multiple neural system abnormalities. This finding provides insight into the potential psychopathology of ATDP. [ABSTRACT FROM AUTHOR]

The severe mortality and morbidity of myocardial infarction requests appropriate and accurate detection. Considering pathological profile of the acidic myocardial infarction microenvironments, herein, the low pH-sensitive albumin nanocomposites with MnO 2 motifs (MnO 2 @BSA) have been engineered for T 1 -weighted MR imaging of myocardial infarction, while using non-pH-responsive Gd 2 O 3 @BSA nanocomposites as control. The nanocomposites were 20–30 nm in diameter with spheroid morphology. Besides, the MnO 2 @BSA have exhibited pH-triggered releasing of Mn2+, demonstrating approximately 38-fold and 55-fold increased molecular relaxivity at acute myocardial infarction-mimicking pH 6.5 (13.08 mM−1s−1) and macrophage intracellular pH 5.0 (18.76 mM−1s−1) compared to the extremely low relaxivity (0.34 mM−1s−1) at normal physiological conditions (pH 7.4). However, the Gd 2 O 3 @BSA with molecular relaxivity approximately 10 mM−1s−1 were without pH-sensitive properties. Furthermore, the MnO 2 @BSA have demonstrated high accumulation in the acute myocardial infarction regions and fast metabolism from the body after systemic injection, accounting high contrast enhancement for accurate MR imaging of acute myocardial infarction in rabbit models, demonstrating better diagnostic performance over the controls. [ABSTRACT FROM AUTHOR]