[Cardiac Magnetic Resonance in Cardiovascular Disease Research and Its Clinical Application: an Update].

Cardiac magnetic resonance (CMR) is a non-invasive imaging technology, which has been used widely in clinical and basic researches on cardiovascular disease in recent years. With the innovation and optimization of CMR technologies, significant progress has been developed in the evaluation of myocardial viability, the function of regions and global myocardium, and the myocardial texture characteristics. Therefore, with the discussion on the progress of CMR to draw more and more attention in clinics, we hope to improve the application of CMR not only in the basic research but also in the diagnosis and precise evaluation aspects of cardiovascular disease.

[Cardiac Magnetic Resonance Imaging Study of Ventricular Myocardial Deformation in Spontaneous T2DM Rhesus Monkey].

OBJECTIVE: To assess biventricular, especially right ventricular, function and deformationin rhesus monkeys with spontaneous type 2 diabetes mellitus (T2DM) using cardiac magnetic resonance (CMR). METHODS: Twelve male spontaneous T2DM rhesus monkeys and age, sex, body mass matched 9 healthy rhesus monkeys without hypertension and myocardial infarction were included in this study. Fasting blood glucose (FPG), glycated hemoglobin (HbA1c) and blood liquid levels were measured. Biventricular function and myocardial deformations were evaluated by CMR cine and tissue-tracking. RESULTS: Compared with control, the FPG and HbA1c levers were significantly increased in T2DM group, but there was no significant difference in body mass and age between the two groups. CMR result showed that there was no significant decrease in right ventricle and left ventricle ejection fraction in T2DM (P < 0.05). However, the absolute value of radial and circumferential global peak systolic strain, systolic strain rate and three directions global peak diastolic strain rate of the right ventricle free wall were lower in the T2DM group (P < 0.05). Also, only radial and circumferential peak systolic strain and radial diastolic strain rate of left ventricle were higher (P < 0.05). CONCLUSIONS: Right ventricle showed systolic and diastolic dysfunction which were consistent with left ventricle in T2DM by CMR-tissue tracking.

[Magnetic Resonance Imaging Tissue Feature Tracking for Cardiac Amyloidosis].

OBJECTIVE: To detect cardiac amyloidosis (CA) using cardiac magnetic resonance feature tracking(CMR-FT). METHODS: Forty-three CA patients and 24 healthy volunteers underwent steady-state free precession cine sequence on 3.0T MRI after injection of Magnevist. Software cvi 42 was used for analyzing the left ventricular function including left ventricular mass (diastole) (LVMD), left ventricular mass (systole) (LVMS), left ventricle end-diastolic volume (LVEDV), left ventricle end-systolic volume (LVESV), left ventricle stroke volume (LVSV), and left ventricular ejection fraction (LVEF), as well as myocardial strains including 3D global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS), and 2D endocardial and epicardial longitudinal strain, circumferential strain, and radial strain (ENDO-LS, EPI-LS, ENDO-CS, EPI-CS, ENDO-RS, and EPI-RS). The global and layer-specific strains were compared between the CA patients with LVEF >50%, the CA patients with LVEF ≤50%, and the healthy controls. RESULTS: For the left ventricular function, the CA patients had greater myocardial mass than the healthy controls (P < 0.05); the CA patients with LVEF ≤50% had greater LVESV and lower LVSV than those with LVEF >50% (P < 0.05). For the global strains, significant differences also appeared in GLS and GCS among the three groups (all P < 0.05). The CA patients had lower GRS than the healthy controls (P < 0.05), while no significant difference was found in GRS between the CA patients with LVEF >50% and those with LVEF ≤50% (P>0.05). For the layer-specific strains, significant differences in ENDO-LS, EPI-LS, ENDO-CS, EPI-CS, ENDO-RS, and EPI-RS were found among the three groups (all P < 0.05). There were significant correlations between GLS and LVEF (r=-0.404, P=0.016), and between GCS and LVEF (r=-0.602, P < 0.001) in the CA patients. CONCLUSION: CMR-FT can assess not only global strains but also layer-specific strains for the myocardial function of CA patients.

[Diagnostic Values and Reliability of Cardiac Magnetic Resonance Tissue Tracking 2D and 3D Strain Assessments for Experimental Autoimmune Myocarditis in Rats].

OBJECTIVE: To determinethe diagnostic valuesand reliabilityof cardiac magnetic resonance tissue tracking (CMR-TT) derived two-dimensional(2D) and three-dimensional(3D) strains in assessing experimental autoimmunity myocarditis (EAM) in rats. METHODS: 20 Lewis rats were randomly divided into model and control groups. The animal model of autoimmune myocarditis was induced by injecting porcine cardiac myosin into the footpads of the rats.On day 35, all of the rats were examined using the 7.0T CMR cine scan. The cardiac function and global strain of the left ventricular of the rats were analyzed with specific cardiac post-processing. The rats were then sacrificed and myocardial samples were taken and stained with HE and Masson. The diagnostic values of the strain parameters were assessed by receiver operating characteristic (ROC) curves with the pathological results as diagnostic criteria.The reliability of the strain parameters were tested using interclass correlation coefficient (ICC), coefficients of variation (CV) and Bland-Altman. RESULTS: No abnormal pathological changes in myocardial cells were found in the control group. Myocarditis was successfully induced in all of the rats in the model group, showing myocardial fiber arrangement disorder, degeneration, necrosis, inflammatory cell infiltration and interstitial fibrosis. The ROC showed that 2D global strain parameters possessed higher diagnostic values than 3D strain parameters. The 2D had an area under the curve (AUC) of 0.96 in global circumferential strain (GCS), 0.95 in global radial strain (GRS), and 0.90 in global longitudinal strain (GLS), compared with 0.87 GCS, 0.85 GRS, and 0.77 GLS in the 3D, respectively.The reliability of the 2D strain parameters was high, except for inter-observer 2D GRS(ICC=0.893). The 3D strain parameters had lower reliability (ICCs:0.421-0.79) than the 2D strain parameters (ICCs:0.893-0.986). CONCLUSION: The diagnostic values of 2D strain parameters are higher than 3D strain parameters in diagnosing myocarditis.

[Evaluating Cardiac Function of Tree Shrew (Tupaiabelangeri) using CMR at 7T with 2D Tissue Tracking].

OBJECTIVE: To determine the potential value of the two-dimensional (2D) cardiac magnetic resonance imaging (CMR) tissue tracking (CMR-TT) method in assessing the cardiac function of tree shrew at 7T. METHODS: Healthy adult tree shrews (male, n=8) and spraguedawley rats(male, n=8) were selected for this study. CMR was performed to acquire the short-axis images of left ventricle at 7T using the same appropriative coil and cine sequence for all experimental animals. The CMR images were processed using the professional cardiac analysis software, calculating ejection fraction (EF), radial peak sysolic strain (Err), circumferential peak sysolic strain (Ecc), radial peak sysolic displacement (DR), and LVM/BM 〔the ratio of left ventricular mass (LVM) to body mass (BM)〕. RESULTS: Cine imaging for the tree shrews was 100% successful following the CMR protocol for the rats, with clearly visible main segments of cardiac. Significant differences in EF, Err, Ecc and DR were found between the two groups of animals (P < 0.01). The tree shrews has lower EF, Err and Ecc than the rats. Err and Ecc appeared in the fifteenth phase in left ventriclar systole in the tree shrews, compared with the tenth phase in the rats.The tree shrews also had higher LVM/BM than the rats. CONCLUSION: The cardiac function of tree shrew can be assessed using the 2D CMR-TT method despite significant differences across species.

[Tracking Early Reperfused Myocardial Infarction using Cardiac MR].

OBJECTIVE: To determine segmental myocardial changes in cardiovascular magnetic resonance feature-tracking (CMR-FT) in the early phase of reperfused myocardial infarction in patients and rats. METHODS: Ten patients receiving percutaneous coronary interventions (2-10 d) and 10 rats with 60 min induced myocardial ischemia followed by reperfusions (48 h and 7 d) were investigated by MRI. The steady state free precession cine and late gadolinium enhancement (LGE) sequences were measured to evaluate the standard short axis of the whole heart after an injection of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA, Magnevist, Bayer Health Care Pharmaceuticals) at a dose of 0.1 mmol/kg. The infarction sizes (all areas were expressed as a percentage of the whole myocardial tissues of left ventricle (LV), end-diastolic volume (EDV) and ejection fractions (EF) were calculated. The MRI cine images were analyzed using the myocardial feature tracking software CVI, estimating the peak value of radial strains (RS) and circumferential strains (CS) of the 16 AHA segments excluding apex cordis. The complete myocardial infarction (CMI) segments, partial myocardial infarction (PMI) segments and non-myocardial infarction (NMI) segments were identified and compared. RESULTS: Patients: The radial strain and circumferential strain of the CMI and PMI segments were smaller than the NMI segment (both P < 0.01). However, there was no significant difference between the CMI and the PMI segment (P>0.05). Rats: No significance differences were found in EF and EDV between the two time period 48 h and 7 d (both P>0.05). The radial strain and circumferential strain of the CMI and PMI segments were smaller than the NMI segment (all P < 0.01). But there was no significance difference between the CMI segment and the PMI segment (P>0.05). No significant changes in the global radial strain and the circumferential strain were found over time (both P>0.05). But the segmental radial strain and circumferential strain became larger over time (all P < 0.05). CONCLUSIONS: The systolic ability of myocardium decreases as a result of reperfusion injury in the early phase of reperfused myocardial infarction. But it can gradually recover over time with reperfusion.

A home-based training program improves caregivers' skills and dementia patients' aggressive behaviors: a randomized controlled trial.

OBJECTIVE: To investigate the effects of an individualized, home-based caregiver-training program for caregivers of elderly patients with dementia and behavioral problems. METHODS: Using a randomized clinical trial in the neurologic clinics of two hospitals and a community care management center in northern Taiwan, we tested an individualized home-based caregiver-training program for managing behavioral problems, with referrals to community services and telephone consultation. Participants were patients with dementia and their caregivers (N = 129): 63 in the intervention group and 66 in the control group. The control group received only written instructions and social telephone follow-ups. Behavioral problems of elderly dementia patients were assessed by the Chinese version of the Cohen-Mansfield Agitation Inventory, community form. Family caregivers' outcomes were measured by the Agitation Management Self-efficacy Scale and the Preparedness and Competence Scales. These instruments were administered before the program and 2 weeks, 3 months, and 6 months afterward. RESULTS: Family caregivers who received the individualized home-based training program had better preparedness (t = 2.72, df = 127, p <0.01), competence (t = 4.77, df = 126, p <0.001), and overall self-efficacy (t = 3.81, df = 127, p <0.001) at 3 months than those in the control group. Moreover, the growth rate by treatment interaction effect was significant for caregiver competence (t = 2.25, df = 127, p <0.05) and overall self-efficacy for managing behavioral problems (t = 2.16, df = 127, p <0.05). The probability of physically aggressive behavior for patients in the intervention group decreased from 0.27 to 0.12. CONCLUSION: Our individualized home-based caregiver-training program improved caregivers' preparedness, competence, and self-efficacy for managing problematic behaviors and decreased physical aggressiveness of elderly patients with dementia.

Dynamic Diffusion Tensor Imaging Reveals Structural Changes in the Bilateral Pyramidal Tracts after Brain Stem Hemorrhage in Rats.

BACKGROUND AND PURPOSE: Few studies have concentrated on pyramidal tract (PY) changes after brain stem hemorrhage (BSH). In this study, we used a diffusion tensor imaging (DTI) technique and histologic identification to investigate longitudinal PY changes on both the contralateral and ipsilateral sides after experimental BSH. METHODS: BSH was induced in 61 Sprague-Dawley rats by infusing 30 µl of autogenous tail blood into each rat's right pons. DTI and motor function examinations were performed repeatedly on days 1, 3, 7, 14, and 28 after surgery. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, and radial diffusivity were measured in the bilateral PYs. The axon and myelin injury in the PY were evaluated by histologic study. RESULTS: As compared with normal controls, the bilateral PYs in rats with induced BSH showed an early decrease and a late increase in FA and an early increase and a late decrease in MD. A progressive decrease in axial diffusivity with dramatic axon loss from day 1 to day 28 after BSH was found bilaterally. The bilateral PYs showed an early increase and a late decrease in radial diffusivity. Early myelin injury and late repair were also detected pathologically in the bilateral PYs of rats with BSH. Thus, the early motor function deficits of rats with BSH began to improve on day 14 and had almost completely disappeared by day 28. CONCLUSIONS: DTI revealed dynamic changes in the bilateral PYs after BSH, which was confirmed by histologic findings and which correlated with motor function alteration. These findings support the idea that quantitative DTI can track structural changes in the bilateral PYs and that DTI may serve as a noninvasive tool to predict the prognoses of patients with BSH.

A patient diagnosed with pauciarticular juvenile rheumatoid arthritis after a mechanical prosthetic valve replacement due to aortic regurgitation.

Valvular heart disease is a rare complication of juvenile rheumatoid arthritis (JRA), with most cases associated with polyarticular JRA. The aortic valve is most commonly affected, and valvular involvement occurs months or years after the onset of JRA. Reported cases of valvular heart disease in patients with JRA in a pauciarticular pattern are rare. We report a case of severe aortic insufficiency in a 12-year-old boy who underwent aortic valve replacement before diagnosis of JRA with a pauciarticular pattern.

Risk of infection in hospitalised children with systemic lupus erythematosus: a 10-year follow-up.

The objective of this study was to investigate infection and sepsis in hospitalised children with systemic lupus erythematosus (SLE). Between 1991 and 2000 we reviewed 72 episodes of suspected infection in 42 children with SLE from all hospitalised children with SLE at a medical center in Taiwan. Data comprised clinical and laboratory characteristics of SLE at the time of infection. Infections were identified and categorised as minor or major. A total of 125 patients (110 girls, 15 boys) were admitted 557 times. Forty-two patients had infections, giving an infection rate of 33.6%. There were a total of 72 infections including 20 proven infections; 61 cases of these were minor infections and 11 cases of these were major infections (10 cases were sepsis). Four patients died because of sepsis. By univariate analysis, major infection (sepsis) was significantly associated with a high SLE disease activity index score, lower complement levels and higher anti-DNA titres. In conclusion, our data confirm that infection is common in hospitalised children with SLE. Sepsis, most frequent in major infections, is associated with disease activity and causes significant mortality. These facts should be borne in mind when children with SLE are hospitalised.