Cardiac magnetic resonance feature tracking myocardial strain analysis in suspected acute myocarditis: diagnostic value and association with severity of myocardial injury.

BACKGROUND: Albeit that cardiac magnetic resonance feature tracking (CMR-FT) has enabled quantitative assessment of global myocardial strain in the diagnosis of suspected acute myocarditis, the cardiac segmental dysfunction remains understudied. The aim of the present study was using CMR-FT to assess the global and segmental dysfunction of the myocardium for diagnosis of suspected acute myocarditis. METHODS: Forty-seven patients with suspected acute myocarditis (divided into impaired and preserved left ventricular ejection fraction [LVEF] groups) and 39 healthy controls (HCs) were studied. A total of 752 segments were divided into three subgroups, including segments with non-involvement (SNi), segments with edema (SE), and segments with both edema and late gadolinium enhancement (SE+LGE). 272 healthy segments served as the control group (SHCs). RESULTS: Compared with HCs, patients with preserved LVEF showed impaired global circumferential strain (GCS) and global longitudinal strain (GLS). Segmental strain analysis showed that the peak radial strain (PRS), peak circumferential strain (PCS), and peak longitudinal strain (PLS) values significantly reduced in SE+LGE compared with SHCs, SNi, SE. PCS significantly reduced in SNi (-15.3 ± 5.8% vs. -20.3 ± 6.4%, p < 0.001) and SE (-15.2 ± 5.6% vs. -20.3 ± 6.4%, p < 0.001), compared with SHCs. The area under the curve (AUC) values of GLS (0.723) and GCS (0.710) were higher than that of global peak radial strain (0.657) in the diagnosis of acute myocarditis, but the difference was not statistically significant. Adding the Lake Louise Criteria to the model resulted in a further increase in diagnostic performance. CONCLUSIONS: Global and segmental myocardial strain were impaired in patients with suspected acute myocarditis, even in the edema or relatively non-involved regions. CMR-FT may serve as an incremental tool for assessment of cardiac dysfunction and provide important additional imaging-evidence for distinguishing the different severity of myocardial injury in myocarditis.

Hemoglobin A1c in type 2 diabetes mellitus patients with preserved ejection fraction is an independent predictor of left ventricular myocardial deformation and tissue abnormalities.

BACKGROUND: Early detection of subclinical myocardial dysfunction in patients with type 2 diabetes mellitus (T2DM) is essential for preventing heart failure. This study aims to search for predictors of left ventricular (LV) myocardial deformation and tissue abnormalities in T2DM patients with preserved ejection fraction by using CMR T1 mapping and feature tracking. METHODS: 70 patients and 44 sex- and age-matched controls (Cs) were recruited and underwent CMR examination to obtain LV myocardial extracellular volume fraction (ECV) and global longitudinal strain (GLS). The patients were subdivided into three groups, including 19 normotensive T2DM patients (G1), 19 hypertensive T2DM patients (G2) and 32 hypertensive patients (HT). The baseline biochemical indices were collected before CMR examination. RESULTS: LV ECV in T2DM patients was significantly higher than that in Cs (30.75 ± 3.65% vs. 26.33 ± 2.81%; p < 0.05). LV GLS in T2DM patients reduced compared with that in Cs (-16.51 ± 2.53% vs. -19.66 ± 3.21%, p < 0.001). In the subgroup analysis, ECV in G2 increased compared with that in G1 (31.92 ± 3.05% vs. 29.59 ± 3.90%, p = 0.032) and that in HT, too (31.92 ± 3.05% vs. 29.22 ± 6.58%, p = 0.042). GLS in G2 significantly reduced compared with that in G1 (-15.75 ± 2.29% vs. -17.27 ± 2.57%, p < 0.05) and in HT, too (-15.75 ± 2.29% vs. -17.54 ± 3.097%, p < 0.05). In T2DM group, including both G1 and G2, hemoglobin A1c (HbA1c) can independently forecast the increase in ECV (ß = 0.274, p = 0.001) and decrease in GLS (ß = 0.383, p = 0.018). CONCLUSIONS: T2DM patients with preserved ejection fraction show increased ECV but deteriorated GLS, which may be exacerbated by hypertension of these patients. Hemoglobin A1c is an index that can independently predict T2DM patients' LV myocardial deformation and tissue abnormalities.

Sequential multi-parametric MRI in assessment of the histological subtype and features in the malignant pleural mesothelioma xenografts.

Objective: It is still a challenge to find a noninvasive technique to distinguish the histological subtypes of malignant pleural mesothelioma (MPM) and characterize the development of related histological features. We investigated the potential value of multiparametric MRI in the assessment of the histological subtype and development of histologic features in the MPM xenograft model. Methods: MPM xenograft models were developed by injecting tumour cells into the right axillary space of nude mice. The T1, T2, R2*, T2*, apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo diffusion coefficient (D*), and perfusion fraction (f) at 14 d, 28 d, and 42 d were measured and compared between the epithelial and biphasic MPM. Correlations between multiparametric MRI parameters and histologic features, including necrotic fraction (NF) and microvessel density (MVD), were analysed. Results: This study found that T2, T2* and IVIM-DWI parameters can reflect the spatial and temporal heterogeneity of MPM. Compared to the epithelial MPM, T2 and T2* were higher and ADC, D, D*, and f were lower in the biphasic MPM (P < 0.05). MRI parameters were different in different stages of epithelial and biphasic MPM. Moderate correlations were found between ADC and tumor volume and NF in the epithelial MPM, and there was a correlation between f and tumor volume and NF and MVD in the two groups. Conclusion: MRI parameters changed with tumor progression in a xenograft model of MPM. MRI parameters may provide useful biomarkers for evaluating the histological subtype and histological features development of MPM.

Reduced Interhemispheric Functional Connectivity in Obsessive-Compulsive Disorder Patients.

Background: Neuroimaging studies have shown that the high synchrony of spontaneous neural activity in the homotopic regions between hemispheres is an important functional structural feature of normal human brains, and this feature is abnormal in the patients with various mental disorders. However, little is known about this feature in obsessive-compulsive disorder (OCD). This study aimed to further analyze the underlying neural mechanisms of OCD and to explore whether clinical characteristics are correlated with the alerted homotopic connectivity in patients with OCD. Methods: Using voxel-mirrored homotopic connectivity (VMHC) during resting state, we compared 46 OCD patients and 46 healthy controls (HCs) matched for age, gender, and education level. A partial correlation analysis was used to investigate the relationship between altered VMHC and clinical characteristics in patients with OCD. Results: Patients with OCD showed lower VMHC than HCs in fusiform gyrus/inferior occipital gyrus, lingual gyrus, postcentral gyrus/precentral gyrus, putamen, and orbital frontal gyrus. A significant positive correlation was observed between altered VMHC in the angular gyrus/middle occipital gyrus and illness duration in patients. Conclusions: Interhemispheric functional imbalance may be an essential aspect of the pathophysiological mechanism of OCD, which is reflected not only in the cortico-striato-thalamo-cortical (CSTC) loop but also elsewhere in the brain.