http://med-sci.cn/cgzcx/en/contents_list.asp?issue=202106 zh-cn An RSS feed for Chinese Journal of Magnetic Resonance Imaging http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.001 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.002 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.003 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.004 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.005 * values on quantitative susceptibility mapping (QSM) and R2^* maps, and to compare their performances. Materials and Methods: Eighty-seven subjects (26 males/61 females) aged from 1 month to 6 years were enrolled in this study. The subjects were divided into two groups (from 1 month to 1-year-old and from ＞1-year-old to 6 years old). Susceptibility and R2^* values of caudate nucleus, putamen, globus pallidus and thalamus were measured and analyzed. The relation of the two parameters and age were explored. Results: From 1 month to 1-year-old, the susceptibility value of QSM in globus pallidus showed significantly positive correlation with age, as well as the R2^* values in deep gray nuclei (all P＜0.001). From ＞1-year-old to 6 years, the susceptibility and R2^* values in each deep gray nucleus exhibited significantly positive correlations with age (all P＜0.05) and the correlation coefficients between susceptibility values and age were higher than R2^* values in caudate nucleus, putamen and globus pallidus. Conclusions: Compared with the R2^* values which could be influenced by brain water content, QSM may be a more preferable method for estimating the changes of iron in deep gray matter nuclei of children aged 0—6 years.]]> Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.006 ^,s disease. And then to assess the reliability and clinical value for AD diagnosis of the automatic quantitative method. Materials and Methods: Structural MRI images were collected from 204 enrolled healthy volunteers. Volume of bilateral hippocampus, bilateral ventricles, bilateral caudate nucleus, bilateral putamen, and bilateral thalamus, were respectively measured by manual segmentation of 2 experienced experts and automatic measurement software. The volumetric data of the 10 regions measured by two methods were compared. Moreover, 34 AD patients, with 34 age- and sex-matched normal controls, were enrolled in the study. Volumes of 47 main brain regions (including frontal lobe, temporal lobe, parietal lobe, occipital lobe, insular lobe, posterior cingulate etc.) of AD and control groups were assessed by automatic measurement software. The difference of absolute volumes and relative volumes (absolute volume/brain parenchymal volume) of brain regions between the two groups were compared, respectively. Results: The results showed that the volume of 10 selected brain regions measured by automatic measurement software had significant correlation with those by manual segmentation of experienced experts (Pearson^,s r2＞0.9). Bland-Altman analysis revealed that the coefficients of variation of volume difference were less than 5%. On the other hand, volume of ventricle, including lateral ventricles, third ventricle, fourth ventricle, in AD group significantly expanded compared with control (P＜0.05), 32 other brain regions in AD group had significant absolute volume atrophy compared with normal control (P＜0.05). Compared with control, 11 brain regions, including medial prefrontal lobe (P=0.0009), middle temporal gyrus (P=0.0003), inferior temporal gyrus (P=0.0012), temporal pole (P=0.0093), angular gyrus (P=0.0030), precuneus (P=0.0052), posterior cingulate gyrus (P=0.0157), amygdala (P＜0.0001), hippocampus (P=0.0016), basal area (P=0.0022), entorhinal area (P=0.0003) in AD group had significant absolute and relative volume decrease. Conclusions: The automatic segmentation software can accurately measure the volume of brain regions which has good consistency with. Assessment of brain structure changes by using automatic measurement software has potential AD diagnostic value.]]> Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.007 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.008 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.009 ^,s upper limb motor function scores (r=-0.735, P＜0.01). Conclusions: The positive and negative network connectivity strength related to hand knob area both decrease following subcortical stroke. In particular, the FC in the stroke group greater than that in the control group does not mean "functional compensation", but reflects the degradation FC in the brain regions related to hand knob area. It may be helpful for our deep understanding of the neuropathyological mechanism of stroke and provide reference for rehabilitation intervention.]]> Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.010 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.011 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.012 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.013 trans), reflux rate constant (K_ep), volume fraction of extravascular extracellular space (V_e) and volume fraction of plasma (V_p). All the liver tissue were sampled for the histopathological Scheuer staging. One-way analysis of variance evaluated the differences of Ktrans, K_ep, V_e and V_p among different groups. Spearman correlation was used to analyze the correlation between K^trans, K_ep, V_e and V_p in different LF stages. Comparing the diagnostic performance of all quantitative parameter values by ROC curve analysis. Results: There were 150 rabbits included in our study, which covered F0 (n=32); F1 (n=32); F2 (n=35); F3 (n=30) and F4 (n=21). Significant differences of K^trans were demonstrated between F0 vs. F2, F3, F4, respectively; F1 vs. F2, F3, F4, respectively; F2 vs. F4 (P＜0.05). There were significant differences in K_ep between F0 vs. F2, F3, F4, respectively; F1 vs. F2, F3, F4, respectively (P＜0.05). There were significant differences in V_p between F1 vs. F0, F2, F3, F4, respectively (P＜0.05). But no significant differences of V_e were shown among all groups (P＞0.05). K^trans and K_ep were correlated with LF stage (r=0.730, -0.617, respectively, P＜0.0001), whereas, no significant correlation was found for V_e or V_p (P＞0.05). The AUCs of K^trans were the greatest than those of the other quantitative parameters (0.897 for F0 vs. F1—F4, 0.863 for F0 vs. F1—F2, 0.942 for F0 vs. F3—F4, 0.809 for F1—F2 vs. F3—F4), while the AUCs of K_ep was 0.820, 0.787, 0.864, 0.768, respectively. Conclusions: The quantitative evaluation of Gd-EOB-DTPA DCE-MRI has definite diagnostic value for LF staging, among which K^trans shows the best diagnostic efficacy.]]> Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.014 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.015 ^,s disease (AD) and provide an auxiliary tool for clinical early diagnosis of AD. Materials and Methods: The progression of AD was divided into four groups, including normal cognitive subjects, early mild cognitive impairment, late mild cognitive impairment and AD. Structure magnetic resonance imaging (sMRI) datas were collected from these subjects. In addition, Age, sex, education level and Mini-Mental State Examination (MMSE) scores were also collected. Then, L1-regularized support vector machine (L1-SVM) algorithm was used to select the features that contributed the most to the classification group based on the two datasets respectively. The extracted feature subsets were classified in the back propagation (BP) neural network model, and compared with Logistic regression, random forest and support vector machine (SVM). The accuracy of the four models was compared with the ten fold cross validation method. The specificity, sensitivity and area under receiver operating characteristic curve (AUC) values of the optimal combination model were given. Results: The feature sets with three demographic indicators and MMSE score were better than that with only sMRI feature set. The classification accuracy of BP neural network algorithm combined with L1-SVM feature selection algorithm was better than other machine learning models, especially in the process of transforming from normal cognitive function to AD. The accuracy of BP neural network was as high as 98.90%, sensitivity was 98.75%, AUC was 1.00. There were slight differences among different classification groups. Conclusions: The combined model of L1-SVM and BP neural network can be used for the early diagnosis of AD, and the relevant characteristic data of each stage of AD progressive transformation provide the basis for clinical basic research and pathological changes.]]> Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.016 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.017 trans) and extravascular extracellular space volume fraction (V_e). The tumor area, extra-tumor edema 1 cm, extra-tumor edema 1—2 cm area and contralateral hemisphere normal white area were the regions of interest, then measured the values of each parameter and analyzed the differences in high and low-grade gliomas. Spearman correlation coefficient was used to analyze the correlation between the parameters and pathological grade of diffuse glioma. Results: The K^trans and V_e in the tumor area and extratumoral edema of the HGG group were higher than those in the LGG group (K^trans value compared, t=7.821, 9.468, 8.670, V_e value compared, t=4.411, 7.812, 2.544; P＜0.05). The K^trans and V_e of two groups in every region were decreasing from tumor area to normal white matter area. In the two groups, there was a statistically significant difference between the tumor area and the extra-tumor edema 1 cm, extra-tumor edema 1—2 cm area and the normal white matter area (HGG group: K^trans value compared, t=5.845, 9.907, 10.654, V_e value compared, t=4.398, 8.194, 9.014; P＜0.05; LGG group: K^trans value compared, t=7.763, 8.085, 8.397, V_e value compared, t=6.719, 7.328, 7.370; P＜0.05). In the HGG group, there was a statistically significant difference between the extra-tumor edema 1 cm and the extra-tumor edema 1—2 cm area, normal white matter area (K^trans value compared, t=6.966, 7.780, V_e value compared, t=7.920, 8.053; P＜0.05), there was no significant difference between the extra-tumor edema 1—2 cm area and the normal white matte area (K^trans value compared, t=1.006, V_e value compared, t=0.617; P＞0.05); in the LGG group, there was no statistically significant difference between the extra-tumor edema 1 cm area and the extra-tumor edema 1—2 cm area (K^trans value compared, t=1.733, V_e value compared, t=1.751; P＞0.05), between the extra-tumor edema 1 cm area and the normal white matter area (K^trans value compared, t= 2.012, V_e value compared, t=2.021; P＞0.05), between the extra-tumor edema 1—2 cm area and the normal white matter area (K^trans value compared, t=0.654, V_e value compared, t=1.184; P＞0.05). K^trans value and V_{e value were positively correlated with pathological grade of diffuse glioma (r=0.811, 0.734, P＜0.05). Conclusions: DCE-MRI can improve the grade of tumor and guide the scope of clinical resection.]]>} Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.018 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.019 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.020 ^,s face of placenta was locally raised or wavy accounting for 73.91% (51/69); ④Anomalous increase of subfacial sinuses in placenta accounting for 71.01%(49/69). All four imaging features were statistically significant (P<0.05). DWI manifestations: placental tissue signals penetrated myometrium in 12 cases, placental nail-like, nodular protrusion into myometrium in 24 cases, there were 46 cases with localized protuberance or wavy appearance of placenta mother, at placenta accreta DWI signal increased slightly, rough 19 cases, 6 cases of signal reduction at b0 placenta implantation, all the five imaging features were statistically significant (P<0.05). Conclusions: Multi mode and multi parameter MRI can provide reliable MRI features in the diagnosis of placenta accreta.]]> Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.022 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.023 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.024 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.025 Sun,20 Jun 2021 00:00:00 GMT http://med-sci.cn/cgzcx/en/en_articlexml.asp?doi=10.12015/issn.1674-8034.2021.06.026 ^,s living standards and changes in lifestyles, the incidence of obesity in adults and children has increased year by year, and obesity and its complications have become the main factors endangering human health. Brown adipose tissue (BAT) makes mitochondrial oxidative phosphorylation and uncoupling through the characteristic high expression of uncoupling protein 1 (UCP1) to convert chemical energy into heat energy. Recent studies have found that BAT is closely related to obesity-related metabolic diseases, which may provide new ideas and ways to treat obesity. At present, MRI quantitative BAT is still in the exploratory stage. Based on the introduction of BAT, the author reviews the MRI detection technology for quantitative analysis of BAT and the clinical application of BAT.]]> Sun,20 Jun 2021 00:00:00 GMT