Lung four dimensional computed tomography (4D-CT) is of great value in tumor target localization and precise cancer radiotherapy. However, it is hard to segment tumors in 4D-CT data manually, since the data may contain a great number of slices with tumor. Meanwhile, auto-segmentation does not certainly guarantee the accuracy due to the complexity of images. Therefore, a new automatic segmentation technique based on Graph Cuts with star shape prior was proposed to increase automation and guarantee the accuracy of segmentation in our laboratory. Firstly, an object seed was selected in the image of initial phase and an initial target block was formed centering the selected seed. Then, the full search block-matching algorithm was adopted to obtain the most similar target block in the next phase and compute the motion field between them, and so on. Afterwards, the center seeds of each phase were obtained according to the motion fields, which would be set to the center point of star shape prior. Finally, tumors could be automatically segmented with Graph Cuts algorithm and star shape prior. Both qualitative and quantitative evaluation results showed that our approach could not only guarantee the accuracy of segmentation but also increase automation, compared with the traditional Graph Cuts algorithm.
Lung four dimensional computed tomography (4D-CT) can lead to accurate radiotherapy. However, for the safety of patients, the scan spacing of 4D-CT cannot be too small so that the inter-slice resolution of lung 4D-CT is low, and thus the coronal and sagittal images need to be interpolated to obtain high-resolution images. This paper presents a super-resolution reconstruction technique based on multi-model Gaussian process regression. We use the high-resolution transversal images and the corresponding low-resolution images as the training sets. The high-resolution pixels of the coronal and sagittal images can be predicted by constructing multiple Gaussian process regression models. The experimental results show that our method is superior to bicubic algorithm, projections onto convex sets, sparse coding, multi-phase similarity based method and Gaussian process regression method based on self-learning block in terms of the edge and detail recovery. The results demonstrate that the proposed method can effectively improve the quality of lung 4D-CT images, and potentially be applied to better image-guided radiation therapy of lung cancer.
ObjectiveTo summarize the clinical features in idiopathic hypotony maculopathy.MethodsA retrospective case series study. Eighteen eyes of 18 patients who were diagnosed with idiopathic hypotony maculopathy were enrolled in the Second Affiliated Hospital of Wenzhou Medical University from August 2012 to December 2017. There were 8 males (8 eyes) and 10 females (10 eyes). All patients underwent examinations including BCVA, optometry, slit lamp microscope, fundus color photography, UBM, B-mode ultrasound, OCT, FFA and axial length (AL). BCVA was recorded with logMAR acuity. The results of affected eyes and contralateral healthy eyes were compared. Paired t test was performed to compare the intraocular pressure (IOP), diopter and AL of the affected eyes and contralateral healthy eyes.ResultsAmong 18 eyes, there were 6 eyes with logMAR BCVA＜1.0, 10 eyes with logMAR BCVA 1.0−2.0, 2 eyes with light perception. The average diopter was +2.32±1.78 D. The average IOP was 5.18±1.38 mmHg (1 mmHg=0.133 kPa). The average AL was 20.92±1.61 mm. The differences of IOP (t=21.6, P＜0.000), diopter (t=5.9, P=0.002) and AL (t=9.13, P＜0.000) between the affected eyes and contralateral healthy eyes were significant. The inflammatory reaction in the anterior segment was observed in 13 eyes (72.22%). In the posterior segment, all the eyes were documented with chorioretinal folds, optic disc swelling and retinal phlebectasia were also demonstrated in 14 eyes, while with macular uplift in 7 eyes. In the UBM and gonioscope examination, the angle chamber was open in all patients with ciliary body cyst in 6 eyes, while no ciliary body detachment was detected. All eyes had been examined with B-scan ultrasound and found the increasing thickness of eye ball in all eyes, and nodular changes in the optic papilla in 5 eyes. The chorioretinal folds were further confirmed by OCT with the appearance of the gear shape, much more obviously in the choroid than that in retina. In the FFA, fluorescein leakage was found around the optic disc in 13 eyes at the late stage, while there was no obvious abnormal leakage in the macular or poster part of retina.ConclusionsIdiopathic hypotony maculopathy could present with various clinical manifestations. The choroiretinal folds is typical clinical sign.
Relative/absolute adrenal insufficiency is not uncommmon in the patients undergoing cardiovascular surgery with cardiopulmonary bypass. However, this complication was rarely reported due to its unspecific clinical presentations and the unawareness of ICU physicians and cardiac surgeons. However, this puts them on a higher risk of hemodynamic instability and cardiovascular adverse events during hospitalization. Systematic reviews concentrated on it are rarely reported currently. We aim to review the etiology, risk factors, potential pathogenesis and related research progress for this complication.
ObjectiveTo investigate the role and potential mechanisms of neuropilin-1 (NRP1) in the pathogenesis of vein graft failure.MethodsThe rat vascular smooth muscle cells (VSMCs) were transfected with NRP1-shRNA adenovirus and negative control adenovirus respectively. Cell counting kit-8, flow cytometry, Transwell and Western blot were used to investigate the effects of inhibition of NRP1 on VSMCs proliferation viability, apoptosis, migration capacity and its downstream signaling pathway protein expression.ResultsThe proliferation and migration of rat VSMCs could be inhibited after down-regulation of NRP1, and the increase of apoptosis was also observed. Moreover, inhibition of NRP1 significantly reduced Akt and NF-κB phosphorylation in rat VSMCs, but had little effect on activation of ERK1/2.ConclusionNRP1 may promote vein graft hyperplastic remodeling by regulating the proliferation and migration of VSMCs through PI3K/Akt and NF-κB pathways, but further animal study is required.
ObjectiveTo analyze the differences in proteins between aneurysm/dissection patients and healthy subjects, and subsequently figure out differential proteins related to medial degeneration of aortic aneurysm/dissection.MethodsAortic wall samples were collected from 6 male aortic aneurysm patients (an aortic aneurysm group, mean age 56.50±8.19 years), 6 male aortic dissection patients (an aortic dissection group, mean age 54.17±6.68 years) and 6 male healthy subjects (a normal group, mean age 40.50±9.31 years) between December 2019 and May 2020 in West China Hospital of Sichuan University. Quantitative proteomics was performed using tandem mass tag (TMT) techniques, followed by gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis.ResultsA total of 63 differential proteins were obtained both in the aortic aneurysm group and the aortic dissection group compared with the normal group, with 30 up-regulating and 33 down-regulating. The differential proteins were involved in multiple biological processes and clusted on peroxisome proliferators-activated receptor (PPAR) signaling pathway, extracellular matrix-receptor interaction signaling pathway and complement and coagulation cascades signaling pathway.ConclusionThe identified proteins may help to demonstrate new molecular mechanisms related to medial degeneration of aortic aneurysm/dissection.