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.

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.

Objective:To explore the feasibility and effectiveness of full free-breathing cardiac magnetic resonance (CMR) in clinical practice.Methods:The study prospectively included patients who underwent full free-breathing CMR and traditional breath-holding cine imaging between June 1 and June 30, 2024. An analysis and comparison were conducted on the image acquisition time, image quality, and left ventricular function parameters under two scanning methods, including left ventricular ejection fraction (LVEF), left ventricular cardiac output (LVCO),left ventricular end diastolic volume (LVEDV), left ventricular end diastolic volume index (LVEDVI), left ventricular end systolic volume (LVESV), left ventricular end systolic volume index (LVESVI), left ventricular stroke volume (LVSV), and left ventricular mass (LVM). In addition, the study conducted both quantitative and qualitative analyses of other sequences in full free-breathing CMR, including T 1 mapping, T 2 mapping, flow imaging, and late gadolinium enhancement (LGE). Group comparisons were performed using the Wilcoxon signed-rank test or paired t-test. Consistency assessments included Bland-Altman analysis, intraclass correlation coefficient ( ICC), and linear regression analysis. Results:Totally, 150 patients were recruited into the study. The average acquisition time of full free-breathing CMR was (22.1±3.1) min, with an average short axis cine sequence examination time of (2.7±0.4) min; The average acquisition time of short axis images in a breath-holding state was (4.9±1.4) min, which was significantly longer than the cine scan in the free-breathing state ( P0.001). The cine and LGE images quality scores obtained from full free-breathing CMR were 4 (4, 4) points and 5 (4, 5) points, respectively, while the cine image quality score obtained in a breath-holding state was 5 (4, 5) points. Compared with traditional breath-hold CMR, free-breathing CMR measurements showed slightly higher LVESV, and LVESVI, while LVEDV, LVEDVI, LVSV, LVCO, LVEF, and LVM were slightly lower, except for LVSV and LVCO, which showed no statistically significant difference, the differences in other cardiac function parameters were statistically significant ( P0.05). However, the two methods demonstrated good consistency( ICC0.947) and correlation (0.808 r0.993, P0.001). The Bland-Altman analysis showed that the bias for all cardiac function parameters was within 8.0%. The Native T 1 and T 2 values for free-breathing CMR were (1 277.5±57.0) ms and 40.1 (38.5, 41.4) ms, respectively, and the results of flow imaging and echocardiography were basically consistent. Conclusions:Free-breathing CMR is feasible and effective in clinical practice, showing a high level of consistency with left ventricular functional parameters obtained from traditional breath-hold scanning. It significantly shortens examination time and holds great clinical value for the promotion and widespread use of CMR.

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.

As a non-invasive imaging modality,cardiac magnetic resonance(CMR)enables a"one-stop"in vivo assessment of cardiac morphology,structure,functional status and histological features,plays an irreplaceable role in the diagnosis,prognosis and risk stratification of cardiovascular diseases.In 2024,CMR has made continuous progress towards precision medicine.Upgraded technologies such as tissue characterization imaging and myocardial strain analysis,are gradually transformed into standard clinical practice.Artificial intelligence and other new algorithms have improved the quality and efficiency of CMR.The application of CMR in non-ischemic heart disease,ischemic heart disease and other areas is highly valued in the new version of various guidelines,highlighting the importance of CMR in the clinical management of cardiovascular diseases.This article aims to systematically review representative achievements of CMR in 2024 from the perspectives of both technological innovation and clinical translation,providing the latest update in this field.

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.

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 observe the value of AcoStream thrombus aspiration catheter for treating intermediate-high risk acute pulmonary embolism(APE).Methods Twenty-six patients with intermediate-high risk APE who underwent treatment with AcoStream thrombus aspiration catheter were retrospectively collected.The immediate technical success rate,procedure success rate and thrombus clearance rate of target vessels were recorded,as well as clinical success rate and complications in perioperative period and the recurrence of pulmonary embolism(PE)during follow-up.Results Among 26 patients with intermediate-high risk APE,the immediate technical success rate was 100%(26/26),the procedure success rate was 92.31%(24/26),and the immediate thrombus clearance rate of target vessels was 63.37%as median,including 16 cases(16/26,61.54%)achieved thrombus clearance rate grade Ⅱ or above.The perioperative period clinical success rate of treating intermediate-high risk APE was 96.15%(25/26).Two patients experienced transient arrhythmia and other 2 patients experienced worsening transient chest tightness during the procedure,and 1 case developed hematoma at the puncture site after treatment.During follow-up,no recurrence of symptomatic PE was observed.Conclusion AcoStream thrombus aspiration catheter was safe and effective for treating intermediate-high risk APE,worthy clinical promotion and application.

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.