RESUMO
Objective: To construct brain structural network based on DTI data,so as to investigate whether the brain structural network of with mild cognitive impairment (MCI) patients has small-world property,also to observe the changes of relevant characteristic parameters. Methods: Brain DTI data of 26 MCI patients (MCI group) and 27 healthy elders (NC group) were collected. The images were preprocessed with PANDA software, and the cerebral cortex was divided into 90 regions using automated anatomical labeling (AAL) template. Diffusion tensor tractography was implemented using deterministic fiber tracing algorithm, and the white matter fiber connection network was constructed with the fiber number (FN) between 2 brain regions as the threshold T value. T value was set in the range of 1-5, step length was 1, then the characteristic parameters of the brain network at different T value were calculated, including average path length (Lp), aggregation coefficient (CP), global efficiency (Eglobal) and local efficiency (Elocal). The network was considered to be a small-world network if γ=C/Crand>1 and λ=L/Lrand≈1 (rand representing relative random networks) or δ=γ/λ>1 were satisfied. The differences of brain structural network characteristic parameters were compared between 2 groups. Results: When 1≤T≤5, MCI group and NC group both met the criteria of γ>1 and λ≈1; LP of MCI group were all higher than those of NC group (all P0.05). When 1≤T≤4, Eglobal of MCI group were all lower than those of NC group (all P<0.05), when T=2, Elocal of MCI group was lower than that of NC group (P<0.05). Conclusion: The brain structural network of MCI patients has small-world property, but its small-world characteristics are impaired.
RESUMO
Objective To explore the diagnostic value of ESWAN in uterine fibroids by analyzing the ESWAN signal of uterine fibroid. Methods Conventional MRI and ESWAN were carried out in thirty-seven patients with uterine fibroids.The differences of ESWAN indexes between uterine fibroids and myometrium were analyzed by paired t-test.The value of ESWAN on diagnosing uterine fibroids was analyzed by receiver operating characteristic curve(ROC curve).Results The magnitude value,phase value,R2* value and T2*value of uterine fibroids were 1 661.69 ± 45.24,(0.006 7 ± 0.007 7)Hz,(26.69 ± 1.04)Hz and(34.68 ± 1.73)ms,respectively.The magnitude value,phase value,R2* value and T2* value of myometrium were 1 790.95 ± 49.04,(0.013 1 ± 0.011 8)Hz,(22.35 ± 0.84)Hz and(42.53 ± 2.16)ms.The magnitude value,phase value and T2* value of uterine fibroids were lower than those of myometrium (P=0.008,P=0.659 and P=0.002).While the R2* value of of uterine fibroids was higher than that of myometrium(P=0.001). The area under curve(AUC)of magnitude value,phase value,R2* value and T2* value were 0.604,0.553,0.666 and 0.662.Conclusion ESWAN can show the differences between uterine fibroids and myometrium ，while the ability to independently diagnose uterine fibroids was modest.