BACKGROUND:Arthroscopic anchor repair has become the main treatment method for rotator cuff tears at present.Among them,the insertion status of the anchor is a key factor in the success or failure of the operation.However,currently,the impact of the insertion depth of the anchor on the stress of the bone tunnel and the anchor under different bone density conditions remains unclear.OBJECTIVE:To explore the stress distribution of the bone tunnel and the anchor when the insertion depth of the anchor varies under different bone density conditions by using three-dimensional finite element analysis technology.METHODS:The CT image data of the humerus of volunteers were collected,and the models of the humerus and the anchor were constructed by using Mimics,3-Matic,and Solidworks software.In 3-Matic,holes with distances of 0,2,4,6,and 8 mm from the surface of the humerus were respectively created at the same position of the humerus and assembled with the anchor.In Mimics,values were assigned based on the CT gray value to obtain a model with normal bone mass(T value ≥-1.0).The parameters were changed to construct models with reduced bone mass(-2.5＜T value＜-1.0)and osteoporosis(T value＜-2.5).In each model,a 70 N pulling force was applied to the anchor along the direction tangent to the inner edge of the bone tunnel.The stress distribution and magnitude of the bone tunnel and the anchor when inserted at different depths under different bone density conditions were observed.RESULTS AND CONCLUSION:(1)When the insertion depth was the same,as the bone density decreased,the maximum equivalent stress of the anchor increased,while the maximum equivalent stress of the bone tunnel decreased.(2)When the bone density was the same,as the insertion depth of the anchor increased,the maximum equivalent stress of the anchor decreased.When the insertion depth was 4 mm,the stress of the bone tunnel was the smallest and the distribution was relatively uniform.The stress of the anchor was mainly distributed around the lower anchor hole and the proximal thread,and the stress of the bone tunnel was mainly at the part in contact with the proximal thread.The increase in the insertion depth would change the uniformity and pattern of the stress distribution,while the bone density had a relatively small impact on the stress distribution pattern.(3)It is concluded that the bone density of the humerus is crucial for the anchor repair of rotator cuff tears.It is recommended that clinicians measure the bone density of the greater tuberosity of the humerus before the operation.Excessive insertion depth of the anchor does not significantly increase its stability.Clinicians can conduct personalized preoperative assessments by using the finite element analysis method in combination with the actual situation of patients to achieve the best surgical results.

BACKGROUND:Arthroscopic anchor repair has become the main treatment method for rotator cuff tears at present.Among them,the insertion status of the anchor is a key factor in the success or failure of the operation.However,currently,the impact of the insertion depth of the anchor on the stress of the bone tunnel and the anchor under different bone density conditions remains unclear.OBJECTIVE:To explore the stress distribution of the bone tunnel and the anchor when the insertion depth of the anchor varies under different bone density conditions by using three-dimensional finite element analysis technology.METHODS:The CT image data of the humerus of volunteers were collected,and the models of the humerus and the anchor were constructed by using Mimics,3-Matic,and Solidworks software.In 3-Matic,holes with distances of 0,2,4,6,and 8 mm from the surface of the humerus were respectively created at the same position of the humerus and assembled with the anchor.In Mimics,values were assigned based on the CT gray value to obtain a model with normal bone mass(T value ≥-1.0).The parameters were changed to construct models with reduced bone mass(-2.5＜T value＜-1.0)and osteoporosis(T value＜-2.5).In each model,a 70 N pulling force was applied to the anchor along the direction tangent to the inner edge of the bone tunnel.The stress distribution and magnitude of the bone tunnel and the anchor when inserted at different depths under different bone density conditions were observed.RESULTS AND CONCLUSION:(1)When the insertion depth was the same,as the bone density decreased,the maximum equivalent stress of the anchor increased,while the maximum equivalent stress of the bone tunnel decreased.(2)When the bone density was the same,as the insertion depth of the anchor increased,the maximum equivalent stress of the anchor decreased.When the insertion depth was 4 mm,the stress of the bone tunnel was the smallest and the distribution was relatively uniform.The stress of the anchor was mainly distributed around the lower anchor hole and the proximal thread,and the stress of the bone tunnel was mainly at the part in contact with the proximal thread.The increase in the insertion depth would change the uniformity and pattern of the stress distribution,while the bone density had a relatively small impact on the stress distribution pattern.(3)It is concluded that the bone density of the humerus is crucial for the anchor repair of rotator cuff tears.It is recommended that clinicians measure the bone density of the greater tuberosity of the humerus before the operation.Excessive insertion depth of the anchor does not significantly increase its stability.Clinicians can conduct personalized preoperative assessments by using the finite element analysis method in combination with the actual situation of patients to achieve the best surgical results.

Heart failure(HF)is the end-stage of various cardiovascular diseases,and its global prevalence is steadily increasing,placing a significant burden on both patients and healthcare systems.As the challenges in diagnosing and treating HF grow,early precise diagnosis,individualized treatment,and monitoring disease progression have become critical issues.The advancement of non-invasive imaging technologies,particularly in ultrasound,computed tomography(CT),nuclear medicine,and magnetic resonance imaging,provides new solutions to address these challenges.Therefore,this special issue focuses on the application of non-invasive imaging in HF,aiming to offer more accurate diagnostic and therapeutic support to clinical practice.This issue highlights the latest advancements in ultrasound,CT,nuclear medicine,and magnetic resonance imaging in HF diagnosis and treatment,emphasizing the unique contributions of each imaging modality in addressing key issues in HF.These studies demonstrate the critical role of non-invasive imaging in early diagnosis,functional assessment,and risk stratification in HF,providing innovative ideas and methods for clinical practice.Although significant progress has been made in imaging technologies for HF management,challenges such as standardization and data integration remain.In the future,the combination of artificial intelligence and multimodal imaging will further enhance the accuracy and efficiency of HF management,while promoting the widespread application of imaging in precision medicine for HF.

Objectives:To investigate the clinical value of cardiac magnetic resonance imaging(CMR)feature-tracking strain analysis in risk stratification of diabetic heart failure with preserved ejection fraction(HFpEF).Methods:In this retrospective study,a total of 215 patients with diabetic HFpEF who underwent CMR at Chinese Academy of Medical Sciences Fuwai Hospital from January 2012 to December 2018 were included.Myocardial strain parameters were calculated using CMR feature-tracking technology.Patients were followed up by medical records or telephone calls.Composite endpoint event,all-cause death or heart failure hospitalization during follow-up were recorded.Patients were divided into event group and event-free group.Univariable and multivariable Cox proportional hazard regression analyses were performed to determine the risk factors for the outcomes in diabetic HFpEF.The effects of hypertension and obesity on the prognosis of diabetic HFpEF patients and whether they affect the prognostic value of CMR feature-tracking strain analysis were also analyzed.Results:During a follow-up of(7.1±1.8)years,93(43.3%)patients had endpoint events(event group),including 28 all-cause deaths and 65 heart failure hospitalization.Compared with the event-free group(n=122),patients in the event group had significantly lower left ventricular ejection fraction,higher prevalence and extent of late gadolinium enhancement,and significantly reduced global longitudinal strain(GLS),global circumferential strain,global radial strain,and global systolic longitudinal strain rate(all P<0.05).The absolute GLS value was significantly lower in event group than in event-free group,regardless of the presence of hypertension and obesity.Multivariate Cox regression analysis showed that estimated glomerular filtration rate(HR=0.983,95%CI:0.972-0.993,P=0.001),left atrial volume index(HR=1.015,95%CI:1.005-1.026,P=0.004),and GLS(HR=1.142,95%CI:1.060-1.231,P<0.001)were independent risk factors for adverse cardiovascular events in diabetic HFpEF patients.However,adjusted N-terminal pro-brain natriuretic peptide was not an independent prognostic factor.The cut-offvalue of GLS to predict outcome was-14.09%from ROC curve analysis.The Kaplan-Meier curve showed that in patients with and without hypertension and obesity,patients with the GLS>-14.09%had lower event-free survival compared to patients with GLS≤-14.09%(all P<0.05),and the ability of GLS to predict adverse outcomes was not affected by hypertension and obesity.Conclusions:GLS obtained by CMR feature-tracking strain analysis is an independent predictor of adverse outcomes in diabetic HFpEF,and its ability to predict adverse outcomes is independent of hypertension and obesity.

Objective To explore the MRI images and clinical characteristics of right ventricular outflow tract obstruction(RVOTO)in hypertrophic cardiomyopathy(HCM)patients.Methods The clinical and imaging data of 30 patients with RVOTO and 55 randomly selected patients with simple left ventricular outflow tract obstruction(LVOTO)were retrospectively analyzed,and the data between the two groups were statistically analyzed.Results The N-terminal pro-B type natriuretic peptide(NT-proBNP)value,the average thickness of left ventricular basal end diastolic anterior wall and anterior septum,the proportion of"scallop sign"on imaging,and the mass percentage of myocardial late gadolinium enhancement(LGE)in RVOTO group were significantly higher than those in LVOTO group(P<0.01).Conclusion RVOTO is the result of multiple factors,including the thickening of interventricular septum,as well as the right ventricular free wall.When the"scallop sign"appears in MRI examinations of HCM patients,it is necessary to be highly vigilant for the presence of RVOTO.

Mesenchymal stem cells (MSCs) have been widely used in the treatment of various autoimmune and inflammation-related diseases due to their potent immunomodulatory properties. Several studies have demonstrated that MSC-mediated immunomodulation is complex and bidirectional, with the in vivo microenvironment influencing the direction of this modulation. Indoleamine-2,3-dioxygenase (IDO), an immunosuppressive factor, has been identified as a key "switch" in the immunomodulatory role of MSCs. In this review, we explore how IDO functions as a critical regulator of MSC immunoregulatory plasticity. We delve into the mechanisms by which changes in IDO expression affect the function of various immune cells, summarize relevant research and clinical advances regarding the role of IDO expression in MSC-based therapies for various diseases, and discuss potential therapeutic strategies that target IDO to enhance the stability of MSC therapeutic effects. This provides a theoretical foundation for optimizing MSCs as safer and more effective clinical therapeutic agents.

Objective To explore the MRI images and clinical characteristics of right ventricular outflow tract obstruction(RVOTO)in hypertrophic cardiomyopathy(HCM)patients.Methods The clinical and imaging data of 30 patients with RVOTO and 55 randomly selected patients with simple left ventricular outflow tract obstruction(LVOTO)were retrospectively analyzed,and the data between the two groups were statistically analyzed.Results The N-terminal pro-B type natriuretic peptide(NT-proBNP)value,the average thickness of left ventricular basal end diastolic anterior wall and anterior septum,the proportion of"scallop sign"on imaging,and the mass percentage of myocardial late gadolinium enhancement(LGE)in RVOTO group were significantly higher than those in LVOTO group(P<0.01).Conclusion RVOTO is the result of multiple factors,including the thickening of interventricular septum,as well as the right ventricular free wall.When the"scallop sign"appears in MRI examinations of HCM patients,it is necessary to be highly vigilant for the presence of RVOTO.

Objective:To comprehensively evaluate the changes in pulmonary artery hemodynamics in patients with repaired tetralogy of Fallot (rTOF) using four-dimensional flow (4D Flow) MRI, and to explore the value of viscous energy loss (EL) as an evaluation parameter of the right heart in patients with rTOF.Methods:A total of 30 rTOF patients who were prospectively admitted at Fuwai Hospital between October 2017 and November 2019, and 19 healthy controls who were prospectively recruited on March 2023, were enrolled in this study. All participants underwent a comprehensive 4D Flow MRI evaluation, and indicators of comparison between the two groups including quantitative flow analysis, wall shear stress (WSS) assessment, and EL evaluation in four planes: the right ventricular outflow tract (RVOT), main pulmonary artery (MPA), right pulmonary artery (RPA), and left pulmonary artery (LPA). The correlation between EL and traditional right ventricular (RV) function parameters, as well as WSS, was analyzed.Results:The RV function was generally decreased in rTOF patients, with an RV ejection fraction of 41.42 (35.85, 43.33) %. Compared with healthy controls, the volumes of backward flow, peak velocities, and both axial and circumferential WSS at the RVOT, MPA, RPA, and LPA were significantly increased in rTOF patients (all P<0.05). The EL in the pulmonary artery was extremely low in healthy controls, with the maximum EL values for the MPA-RPA and MPA-LPA segments during cardiac cycle being 0.51 (0.42, 0.73) and 0.68 (0.40, 0.94) mW, respectively. However, in rTOF patients, the EL values were as high as 63.63 (35.35, 82.15) and 56.41 (34.96, 88.76) mW, respectively. There was a significant moderate negative correlation between EL and RV ejection fraction, and a moderate to high positive correlation between EL with RV volume index, regurgitation fraction, as well as peak velocities (all P<0.05). Additionally, there was a significant positive correlation between EL and axial and circumferential WSS, with the correlation coefficients at MPA ranging from 0.67 to 0.88 (all P<0.05). Conclusions:Disordered flow in the pulmonary artery is common in patients with rTOF and should not be overlooked. The extensive viscous EL is closely associated with traditional RV function parameters and WSS. EL is expected to become an crucial parameter for evaluating right heart function in rTOF patients.

The American College of Cardiology/American Heart Association,in collaboration with other societies/associations,has issued"the 2023 Multimodality Appropriate Use Criteria for the Detection and Risk Assessment of Chronic Coronary Disease".This guideline aims to provide appropriate use criteria for the use of functional stress testing and anatomical diagnostic methods in the evaluation of known or suspected chronic coronary disease.The updated content of the guideline is of significant importance for guiding clinical practitioners in China to apply cardiovascular imaging techniques rationally,to detect chronic coronary disease patients at an early stage,and to conduct risk assessments accurately,thereby ensuring high-quality clinical management of patients with chronic coronary disease.

Objective:To investigate the clinical characteristics and cardiac magnetic resonance (CMR) features of cardiac sarcoidosis (CS).Methods:This retrospective study included 8 consecutive patients with pathologically confirmed CS by endomyocardial biopsy from Fuwai Hospital, Chinese Academy of Medical Sciences, between January 2012 and September 2024. All patients underwent comprehensive CMR examinations including cine imaging and late gadolinium enhancement (LGE) imaging. Clinical data, including electrocardiographic findings, were collected. CMR phenotyping was performed based on imaging characteristics, and cardiac structure and function parameters were evaluated. LGE analysis was conducted using the American Heart Association 17-segment model to assess the distribution patterns and involvement sites.Results:The most common clinical symptoms were chest tightness (4 patients), palpitations (4 patients), and shortness of breath (6 patients). Electrocardiographic abnormalities included atrioventricular block in 4 patients, right bundle branch block in 2 patients, left bundle branch block in 2 patients, frequent premature ventricular contractions in 4 patients, and non-sustained ventricular tachycardia in 5 patients. CMR phenotyping revealed hypertrophic cardiomyopathy pattern in 3 patients, with 2 patients maintaining normal biventricular function and 1 patient showing significantly reduced biventricular systolic function. Dilated cardiomyopathy pattern was identified in 4 patients, all demonstrating significantly impaired biventricular systolic function. One patient exhibited another phenotype with preserved biventricular systolic function. LGE analysis demonstrated that the anterior wall and anterior septum (segments 1, 2, 7, 8) were the most frequently involved regions, followed by the lateral and inferior walls (segments 5, 6, 11, 12). Subepicardial involvement was the predominant pattern of myocardial enhancement.Conclusions:Cardiac sarcoidosis exhibits diverse clinical manifestations and heterogeneous imaging characteristics. CMR not only provides a comprehensive assessment of cardiac structure and function but also reveals distinctive myocardial tissue characteristics, particularly the extent and distribution patterns of LGE involvement. These findings have significant reference value for early identification of CS and differential diagnosis from other cardiomyopathies.