Objective To establish normal reference values for left ventricular trabecular and papillary muscle mass(TPMM)in Chinese adults using MRI and to explore its impact factors.Methods A total of 168 healthy Chinese adults were retrospectively included,and compacted and total left ventricular myocardial mass(LVM)were measured using traditional and dedicated methods,respectively.TPMM was calculated from the difference between total and compacted LVM.Independent sample t-tests and analysis of variance were used to explore the differences in TPMM among genders and age groups,while multiple linear regression was used to explore the independent correlation between TPMM and age,gender,heart rate,systolic blood pressure(SBP),fasting blood glucose(FBG),and body mass index(BMI).Results TPMM for men was significantly larger than that for female(P<0.001).TPMM in the elderly group was significantly larger in female(P<0.05),but not in men.Multiple linear regression showed that BMI and SBP were both independently positively correlated with TPMM,and female and heart rate were independently negatively correlated with TPMM(P<0.05).Conclusion This study provides age-and gender-specific normal reference values for TPMM in Chinese adults.Gender,heart rate,BMI,and SBP are all independently associated with TPMM.

L-dopa (l-3,4-dihydroxyphenylalanine)-induced dyskinesia (LID) is a debilitating complication of dopamine replacement therapy for Parkinson's disease. The potential contribution of striatal D₂ receptor (D₂R)-positive neurons and downstream circuits in the pathophysiology of LID remains unclear. In this study, we investigated the role of striatal D₂R⁺ neurons and downstream globus pallidus externa (GPe) neurons in a rat model of LID. Intrastriatal administration of raclopride, a D₂R antagonist, significantly inhibited dyskinetic behavior, while intrastriatal administration of pramipexole, a D₂-like receptor agonist, yielded aggravation of dyskinesia in LID rats. Fiber photometry revealed the overinhibition of striatal D₂R⁺ neurons and hyperactivity of downstream GPe neurons during the dyskinetic phase of LID rats. In contrast, the striatal D₂R⁺ neurons showed intermittent synchronized overactivity in the decay phase of dyskinesia. Consistent with the above findings, optogenetic activation of striatal D₂R⁺ neurons or their projections in the GPe was adequate to suppress most of the dyskinetic behaviors of LID rats. Our data demonstrate that the aberrant activity of striatal D₂R⁺ neurons and downstream GPe neurons is a decisive mechanism mediating dyskinetic symptoms in LID rats.
Rats ; Animals ; Levodopa/toxicity* ; Dopamine ; Parkinsonian Disorders/drug therapy* ; Oxidopamine ; Dyskinesia, Drug-Induced ; Corpus Striatum/metabolism* ; Neurons/metabolism* ; Receptors, Dopamine D2/metabolism* ; Antiparkinson Agents/toxicity*

Objective To examine the nonhuman primate(NHP)model of acute cerebral infarction thrombus-thrombolysis using multi-parameter high-field magnetic resonance imaging(MRI). Methods Altogether, 8 adult male rhesus monkeys aged 8.2(± 1.2)years old and weighing 9.4(± 1.0)kg were randomized into an infarction group(n=4)and thrombolysis group(n =4). Middle cerebral artery occlusion(MCAO)was induced with a clot in the M1 segment. Monkeys in the thrombolysis group were treated with the recombinant tissue plasminogen activator, rt-PA, while those in the infarction group were treated with 0.9% NaCl only. T2 weighted imaging(T2WI), T2-weighted-fluid-attenuated inversion recovery(T2-FLAIR), time-of-flight magnetic resonance angiography(TOF-MRA), and diffusion-weighted imaging(DWI)were used to examine all monkeys at 4 and 24 h after onset of ischemia. Results The rhesus monkey thrombus-thrombolysis model was successfully established. MRA showed that the middle cerebral artery(MCA) was not recanalized in the infarction group, but was recanalized in the thrombolysis group. T2WI sequence showed an increase in infarction volume(12 027 ± 5507 mm3)in the infarction group compared with the thrombolysis group(4910 ± 2764 mm3). DWI sequence showed an increase in infarction volume(9498 ± 5226 mm3)in the infarction group and thrombolysis group(4854 ± 1792 mm3). Both T2WI and DWI sequences showed no significant difference in infarction volume at 4 h between the two groups, while infarction volume in the thrombolysis group at 24 h was significantly lower compared with the infarction group. The increase in infarction volume was significantly lower in the thrombolysis group compared with the infarction group. Conclusions MRI sequences can be used to successfully evaluate recanalization and infarct changes in the thrombus-thrombolysis model in rhesus monkeys.

With the attention to CT radiation and contrast-induced nephropathy,the technology of "double low" CTA has been gradually applied in clinical practice and become a research hotspot in recent years.The "double low" CTA technology aims to reduce X-ray dose and iodine intake of subject in ensuring image quality to meet the diagnostic requirements.The concept of "double low",basic principles,scanning standard protocols and current status of clinical application of "double low" were reviewed in this paper.

Alzheimer disease (AD) is the most common cause of dementia in the aging people.The early diagnosis is very important to slow down the progression and improve the prognosis of AD.At present,most researches focus on the subjective cognitive decline (SCD),which is considered as the preclinical stage of AD.The use of biological markers to predict whether the progress of SCD to AD is necessary.The progresses of imaging studies on SCD were reviewed in this article.

Objective To evaluate the value of procalcitonin(PCT) and endotoxin(ET) in early diagnosis and prognosis in critically illness patients with sepsis.Methods A total of 104 cases with suspected sepsis were prospectively collected in this study from February 2015 to October 2016 in ICU.There were 31 cases of systemic inflammatory response syndrome (SIRS group),30 cases of sepsis 24 cases of severe sepsis and 19 cases of septic shock.Prognosis was observed in patients with sepsis discharged,57 cases were survival (survival group) while 16 cases were dead (death group).The level of PCT and ET and the clinical characteristics were recorded,The the ROC curve was applied to evaluate the discriminative power of variables.Results The levels of PCT,APACHE-Ⅱ score,ET of cases with sepsis,severe sepsis and septic shock were significantly higher than those in SIRS group(P<0.05).The PCT and APACHE-Ⅱ scores were elevated by the severities of disease (P<0.05).ROC curve analysis showed that,the sensitivity of PCT value was 82.2% and specificity was 87.5%.PCT and APACHE-Ⅱ scores were higher in the death group (P<0.05),whereas there was no significant difference on ET between the two groups (P>0.05).ROC curve showed that AUC of PCT was 0.867,which was significantly higher than that for APACHE-Ⅱ score (AUC=0.762) (P>0.05).Conclusion Compared with APACHE-Ⅱ score and ET,PCT can help clinicians to early diagnose and treat cases with sepsis.

The hybrid PET/MR has a unique advantage of simultaneous scanning of both PET and MRI images,which has been gradually applied in clinical practice.In the clinical studies of severe brain diseases (such as cerebrovascular disease,brain tumor and epilepsy),accurate quantification of cerebral blood flow (CBF) can help to understand the etiology,pathogenesis,and to make early diagnosis as well as therapeutic solutions.The hybrid PET/MR can implement a noninvasive,convenient and accurate method of arterial input function for quantification of CBF.The application of the hybrid PET/MR in quantification of cerebral blood flow were reviewed in this article.

Neuromyelitis optica (NMO) is an inflammatory-demyelinating disease of central nervous system that is characterized by severe attacks of optic neuritis (ON) and longitudinally extensive transverse myelitis (LETM).Conventional MRI is the most sensitive method in detection of NMO lesions in brain,spinal cord and optic nerve,which can objectively show the site,number,size and distribution of lesions.The MRI features of NMO lesion in brain,spinal cord and optic nerve lesions were reviewed in this article.

By taking Vrije University Medical Center as an example, this paper introduced the cur-rent Neuroradiologist education training system which had the characteristics of training in a comprehen-sive and focused way, multi-disciplinary integration and paying attention to the combination of academic and clinical research. Through the comparison of the status quo of China's sub specialist training, Neuro-radiologist education training system in the Netherlands provided an important reference for China's sub specialty training.

Objective To explore a new index for reflecting the topological information of brain functional networks in patients at high risk of Alzheimer disease using characteristics of resting-state functional connectivity strengths(FCS) in patients with amnestic mild cognitive impairment(aMCI). Methods Thirty-one aMCI patients and 42 age, gender and years of education matched normal controls were enrolled between September 2009 and April 2011 in this study. The resting-state functional MRI (rs-fMRI) data of all participants were acquired and preprocessed. Then the whole-brain functional connectivities were constructed for exploring the distribution characteristics of hub regions which had higher FCS values. Using two-sample t test to compare group differences in age, years of education and each neuropsychological assessment. In addition, using Chi-squared test to compare group differences in gender. Group differences in FCS values were analyzed by general linear model. Finally, correlation analyses were used to evaluate the relationships between the FCS values of the brain regions with group differences and behavioral scores in aMCI patients. Results The hub regions of the functional networks in the aMCI patients were mainly located in the association cortices such as the precuneuses, posterior cingulate cortices, medial prefrontal cortices, angular gyri, superior occipital gyri, fusiform gyri and lingual gyri. The distribution models in the aMCI patients were consistent with those in the normal controls. However, the FCS values of these brain regions were significantly lower in the aMCI patients than those in the normal controls. In comparison to the normal controls, the aMCI patients had significantly decreased FCS values in the bilateral fusiform gyri, lingual gyri, superior occipital gyri, left middle occipital gyrus and postcentral gyrus (the cluster was 389, 230, 187 and 107 voxels, respectively;P<0.05, respectively), and they had decreased trends of FCS values in the bilateral posterior cingulate cortices and right insulas. The correlation analysis with uncorrected conditions showed that the FCS values of the left postcentral gyri were correlatid with the clock drawing test (CDT) scores (r=0.436, P=0.026). Conclusions aMCI mainly attacks the hub regions of brain functional networks. The changes of functional connectivities in aMCI may reflect the early pathophysiologic alterations of AD.