[Role of Dual-layer Detector Energy Spectral CT in Resting Myocardial Perfusion Imaging for Patients with Normal Coronary Artery].

Objective To investigate the role of dual-layer detector energy spectral CT in resting myocardial perfusion imaging for patients with normal coronary artery. Methods One hundred and fifty-six patients with suspected coronary heart disease underwent dual-layer detector energy spectral CT coronary angiography,and resting myocardial perfusion imaging was performed for 28 patients with normal coronary artery.According to American Heart Association's 17-segmentmodel,the iodine density and effective atomic number(Zeff value)of each myocardial segment(except for apical segment)were measured and normalized to those of the aorta.All the data were quantitatively evaluated using ANOVA or Friedman test. Results Iodine density and Zeff value of myocardial segments in middle plane were significantly different(all P<0.001).The iodine density and Zeff value showed no significant difference between segments in basal and apical plane(all P > 0.05). Conclusions Iodine density and Zeff value of myocardial segments can be quantitatively evaluated using dual-layer detector energy spectral CT.Resting myocardial perfusion of segments in middle plane are significantly different in patients with normal coronary artery.

Alterations of regional homogeneity in Parkinson's disease with mild cognitive impairment: a preliminary resting-state fMRI study.

PURPOSE: Mild cognitive impairment (MCI) is commonly observed in Parkinson's disease (PD), even in the early stages. However, the neural substrates of cognitive impairment in PD remain unclear. The aim of the current study was to investigate the change of local brain function in PD patients with MCI. METHODS: Fifty patients with PD, including 25 PD patients with MCI (PD-MCI) and 25 PD patients with normal cognition (PD-NC), and 25 age- and sex-matched healthy controls (HC) were enrolled. Conventional magnetic resonance imaging (MRI), 3D structural images, and resting state-functional MRI (rs-fMRI) were performed in all subjects. Regional homogeneity (ReHo) was measured based on the rs-fMRI images to investigate the altered local brain functions. RESULTS: Brain regions with decreased ReHo were located in the left posterior cerebellar lobe in PD sub-groups compared to the HC group, and the brain regions with increased ReHo were located in the limbic lobe (right precuneus/bilateral middle cingulate cortex) in PD-MCI compared with HC group. PD-MCI presented with increased ReHo in the bilateral precuneus/left superior parietal lobe and decreased ReHo in the left insula compared to PD-NC. ReHo values for the left precuneus were negatively related to neuropsychological scores, and ReHo values for the left insula were positively related to neuropsychological scores in PD subjects. CONCLUSION: The present study demonstrated abnormal spontaneous synchrony in the left insula and left precuneus in patients with PD-MCI compared to PD-NC, which might provide a novel insight into the diagnosis and clinical treatment of cognitive impairment in PD.