Altered resting-state hippocampal functional connectivity in breast cancer survivors with chemotherapy-induced amenorrhea.

INTRODUCTION: Amenorrhea induced decrease of hormones is associated with cognitive impairment. This study aimed to evaluate hippocampal functional connectivity patterns in chemotherapy-induced amenorrhea (CIA) breast cancer (BC) patients, to evaluate the relationship between the functional connectivity features and hormone levels. METHOD: Neuropsychological test, functional magnetic resonance imaging, and assessment of hormone levels were conducted in 21 premenopausal BC patients before chemotherapy (t0 ) and 1 week after completing chemotherapy (t1 ). Twenty matched healthy controls (HC) were also included and underwent the same assessments at similar time intervals. Mixed effect analysis and paired t-test were used to compare differences in brain functional connectivity. RESULTS: Voxel-based paired t-tests revealed increased functional connectivity of the right and left hippocampus with the left fusiform gyrus, inferior and middle temporal gyrus, inferior occipital gyrus, left lingual gyrus, and parahippocampal gyrus after chemotherapy (p < .001) in CIA patients. Repeated measures analysis revealed significant group-by-time interactions in the left hippocampus with the bilateral fusiform gyrus, right parahippocampal gyrus, left inferior temporal gyrus, and left inferior occipital gyrus (p < .001). Premenopausal BC patients had no significant differences in cognitive function compared with HC at baseline. However, the CIA patients had high levels of self-rating depression scale, self-rating anxiety scale, total cholesterol, and triglycerides. Further, the CIA patients showed significant differences in hormone and fasting plasma glucose levels and cognitive performances between t0 and t1 (p < .05). Functional connectivity changes between the left hippocampus and the left inferior occipital gyrus was negatively correlated with E2 and luteinizing hormone changes (p < .05). CONCLUSION: The CIA patients had cognitive dysfunction mainly in memory and visual mobility. Chemotherapy may affect hippocampal-posterior cortical circuit which mediates visual processing in CIA patients. Moreover, E2 may be involved in this process.

A feasibility study of 70 kV double low-dose coronary imaging technique in abdomen-fatty patients using dual-source CT.

Objective: To investigate the aplication of low contrast agent concentration and low tube voltage in coronary CTA on patients with high BMI (26kg/m228kg/m2). Methods: 60 patients with high BMI (26kg/m228kg/m2) were randomly divided into two groups: double low group A (n=30, tube voltage = 70 KV), double low group B (n=30, tube voltage = 70 KV), processed by SAFIRE iterative reconstruction with 270 mgI/ml contrast agent. Conventional group a (n=30, tube voltage = 120 KV), conventional group b (n=30, tube voltage = 120 KV), with filtered back projection (FBP) and 370 mg I/ml contrast agent. the image excellent index (FOM), the effective radiation dose (ED), mean CT value, signal-to-noise ratio (SNR), and contrast-to-noise ratio(CNR) between corresponding groups were compared. Result: There was no significant difference in subjective scores of coronary artery image quality between the two high BMI subgroups (P>0.05).The ED of group A (1.103±0.101 mSv) was significantly lower than that of group a (4.663±0.412 mSv) (P<0.001).There was no significant difference in mean CT value, SNR and CNR between the two subgroups (P>0.05).The image excellent index (FOM) of group A was higher than that of group a (P<0.05).The total iodine content and iodine injection rate in group A were lower than those in group a (P<0.001).The difference of subjective scores of coronary artery image quality between the two ultra-high subgroups was significant. The mean CT value, SNR and CNR of group B were lower than those of group b (P<0.05). The images of 14 patients in group B could not meet the diagnosis demand. Conclusion: It is feasible to reduce the tube voltage to 70KV in patients with abdominal BMI with high BMI (26Kg/m228Kg/m2), under the same conditions, the 70KV can not meet the daily diagnosis requirement.

Ladder-Like Low Iodine Delivery Rate Injection Protocols Based on BMI at 70 KV by Automated Tube Voltage Selection in Coronary CTA.

Objective: To evaluate the feasibility of reducing the injection velocity and volume of contrast agent according to BMI, and the effect of body weight (BW), body surface area（BSA）, body mass index（BMI），and blood volume (BV) on aortic contrast enhancement when the voltage of third-generation dual-source CT is selected at 70 KV. Methods: A total of 280 patients selected at 70 KV were randomly divided into an experimental group and a control group. Each group was divided into 7 subgroups according to BMI ≤20, 20-21, 21-22, 22-23, 23-24, 24-25, and 25-26. The experimental group uses 2.3/2.4/2.5/2.6/2.7/2.8/2.9 ml/s injection speed with 350 mgI/ml contrast agents according to the subgroups; injection time was fixed at 10 s. In the control group, the fixed injection flow rate was 3.5 ml/s, time was 12 s with a total of 42 ml. Subjects in both groups were inspected to adaptive prospective ECG-gating sequence scanning, and subjective and objective image quality of the two groups were compared using Student's t-test. BMI, BSA, and BV were calculated from the patient's body weight and height. We assess the relationship between aortic attenuation and BW, BMI, BV, and BSA using regression analysis or correlation analysis. Results: Significant differences exist in vascular enhancement between the two groups; SNR and CNR of objective image quality in the experimental group were lower than those in the control group (P < 0.05). Both groups had the same subjective image scores (P > 0.05). The number of vessels in the optimal enhancement range counts more in the experimental group than in the control group (χ2 value = 334.25, P ＜ 0.05). In the control group, a weak to medium correlation was seen between vascular enhancement and BMI (r = -0.20), BW (r = -0.42), BSA (r = -0.46), and BV (r = -0.48) (P ＜ 0.05 for all). Conclusions: Compared to BW, BSA, and BV, a weaker negative correlation exists between vascular enhancement and BMI when ATVS selects 70 KV. However, as a much easier way to operate, the stepped low flow and low-contrast agent injection based on BMI was feasible, and the image quality was more homogenized than that of the control group.

A triple-star system with a misaligned and warped circumstellar disk shaped by disk tearing.

Young stars are surrounded by a circumstellar disk of gas and dust, within which planet formation can occur. Gravitational forces in multiple star systems can disrupt the disk. Theoretical models predict that if the disk is misaligned with the orbital plane of the stars, the disk should warp and break into precessing rings, a phenomenon known as disk tearing. We present observations of the triple-star system GW Orionis, finding evidence for disk tearing. Our images show an eccentric ring that is misaligned with the orbital planes and the outer disk. The ring casts shadows on a strongly warped intermediate region of the disk. If planets can form within the warped disk, disk tearing could provide a mechanism for forming wide-separation planets on oblique orbits.

Predictive Value of Early Response to Chemoradiotherapy in Advanced Esophageal Squamous Cell Carcinoma by Diffusion-Weighted MR Imaging.

OBJECTIVE: To explore the value of diffusion-weighted imaging for early response detection of locally advanced esophageal squamous cell carcinoma with concurrent chemoradiotherapy. METHODS: Fifty-five (42 males, 13 females) patients with locally advanced esophageal cancer who were undergoing chemoradiotherapy were recruited for this study. Diffusion-weighted imaging was performed in all patients before therapy, at the first weekend, the second weekend, and the end of chemoradiotherapy. The rate of change in apparent diffusion coefficient value and the maximum diameter between pretherapy and posttherapy were calculated. RESULTS: Fifty-five patients with locally advanced esophageal squamous cell carcinoma were classified as responders (40 cases) and nonresponders (15 cases). Before chemoradiotherapy, the responders group had a significantly lower apparent diffusion coefficient values than the nonresponders group (t = -4.815, P = .000). At the 3 time points after chemoradiotherapy (first weekend, second weekend, and the end of chemoradiotherapy), there was no statistically significant difference in apparent diffusion coefficient values between responders and nonresponders (P > .05). The responders group had a significantly higher rate of change in apparent diffusion coefficient value than the nonresponders group at each time point (P < .05). At the first weekend of chemoradiotherapy, the rate of change in the maximum diameter was not significantly different in the 2 groups (t = 0.928, P = .357). There was a negative correlation between the tumor apparent diffusion coefficient value of pretherapy and the reduction ratio of tumor maximum diameter at the end of chemoradiotherapy (r = -0.592, P = .000). CONCLUSIONS: The change rate of apparent diffusion coefficient value by the end of the first week after beginning chemoradiotherapy may be a sensitive indicator to detect the early response to locally advanced esophageal squamous cell carcinoma.

Multi-contrast imaging information of coronary artery wall based on magnetic resonance angiography.

In order to explore the most suitable image acquisition method for coronary artery wall, the display ability and image quality of segmentation breath-holding target volume acquisition method (the breath-holding method) and real-time navigation whole-hearted acquisition method (the navigation method) of coronary artery magnetic resonance angiography (CMRA) were compared. 26 healthy volunteers were selected to accept the CMRA in 1.5 tunnels magneto-resistance (TMR) equipment by the 2 acquisition methods respectively. The arteries were divided into 9 segments according to the standards of the American Heart Association (AHA). The images were evaluated by 2 magnetic resonance physicians. Satisfaction rate and success rate of each segment of the coronary artery were counted. The results showed that the signal to noise ratio (SNR) and the carrier to noise ratio (CNR) of the images obtained by the breath-holding method were higher than those obtained by the navigation method (P<0.05). Therefore, the segmentation breath-holding target volume acquisition method is proved to have a higher image quality and the simpler and more convenient operations, which is more suitable for the acquisition of positioning images of CMRA.

Two-Steps Coronary Artery Segmentation Algorithm Based on Improved Level Set Model in Combination with Weighted Shape-Prior Constraints.

Due to the complex topological structure of the coronary artery and the uneven distribution of the contrast agent, the angiography images are inevitably blurred and has low contrast, which causes great difficulty in process of segmentation. For this problem, a two-steps segmentation algorithm based on Hessian matrix and level set is proposed in this paper. Firstly, potential blood vessels of coronary images are preliminary extracted via Hessian matrix eigenvalues feature vectors of the geometric features and the response function. Then a novel regularization and area constraint is introduced into the local data energy fitting functional. Finally, the precision of Coronary Artery image is obtained in the evolution of the level set function. Experiments show that our proposed algorithm has better performance to these comparison segmentation algorithms.

Exoplanet orbital eccentricities derived from LAMOST-Kepler analysis.

The nearly circular (mean eccentricity [Formula: see text]) and coplanar (mean mutual inclination [Formula: see text]) orbits of the solar system planets motivated Kant and Laplace to hypothesize that planets are formed in disks, which has developed into the widely accepted theory of planet formation. The first several hundred extrasolar planets (mostly Jovian) discovered using the radial velocity (RV) technique are commonly on eccentric orbits ([Formula: see text]). This raises a fundamental question: Are the solar system and its formation special? The Kepler mission has found thousands of transiting planets dominated by sub-Neptunes, but most of their orbital eccentricities remain unknown. By using the precise spectroscopic host star parameters from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) observations, we measure the eccentricity distributions for a large (698) and homogeneous Kepler planet sample with transit duration statistics. Nearly half of the planets are in systems with single transiting planets (singles), whereas the other half are multiple transiting planets (multiples). We find an eccentricity dichotomy: on average, Kepler singles are on eccentric orbits with [Formula: see text] 0.3, whereas the multiples are on nearly circular [Formula: see text] and coplanar [Formula: see text] degree) orbits similar to those of the solar system planets. Our results are consistent with previous studies of smaller samples and individual systems. We also show that Kepler multiples and solar system objects follow a common relation [[Formula: see text](1-2)[Formula: see text]] between mean eccentricities and mutual inclinations. The prevalence of circular orbits and the common relation may imply that the solar system is not so atypical in the galaxy after all.

Imaging the water snow-line during a protostellar outburst.

A snow-line is the region of a protoplanetary disk at which a major volatile, such as water or carbon monoxide, reaches its condensation temperature. Snow-lines play a crucial role in disk evolution by promoting the rapid growth of ice-covered grains. Signatures of the carbon monoxide snow-line (at temperatures of around 20 kelvin) have recently been imaged in the disks surrounding the pre-main-sequence stars TW Hydra and HD163296 (refs 3, 10), at distances of about 30 astronomical units (au) from the star. But the water snow-line of a protoplanetary disk (at temperatures of more than 100 kelvin) has not hitherto been seen, as it generally lies very close to the star (less than 5 au away for solar-type stars). Water-ice is important because it regulates the efficiency of dust and planetesimal coagulation, and the formation of comets, ice giants and the cores of gas giants. Here we report images at 0.03-arcsec resolution (12 au) of the protoplanetary disk around V883 Ori, a protostar of 1.3 solar masses that is undergoing an outburst in luminosity arising from a temporary increase in the accretion rate. We find an intensity break corresponding to an abrupt change in the optical depth at about 42 au, where the elevated disk temperature approaches the condensation point of water, from which we conclude that the outburst has moved the water snow-line. The spectral behaviour across the snow-line confirms recent model predictions: dust fragmentation and the inhibition of grain growth at higher temperatures results in soaring grain number densities and optical depths. As most planetary systems are expected to experience outbursts caused by accretion during their formation, our results imply that highly dynamical water snow-lines must be considered when developing models of disk evolution and planet formation.