RNA-seq-based comparative transcriptome analysis reveals the role of CsPrx73 in waterlogging-triggered adventitious root formation in cucumber.

Abiotic stressors like waterlogging are detrimental to cucumber development and growth. However, comprehension of the highly complex molecular mechanism underlying waterlogging can provide an opportunity to enhance cucumber tolerance under waterlogging stress. We examined the hypocotyl and stage-specific transcriptomes of the waterlogging-tolerant YZ026A and the waterlogging-sensitive YZ106A, which had different adventitious rooting ability under waterlogging. YZ026A performed better under waterlogging stress by altering its antioxidative machinery and demonstrated a greater superoxide ion (O 2-) scavenging ability. KEGG pathway enrichment analysis showed that a high number of differentially expressed genes (DEGs) were enriched in phenylpropanoid biosynthesis. By pairwise comparison and weighted gene co-expression network analysis analysis, 2616 DEGs were obtained which were categorized into 11 gene co-expression modules. Amongst the 11 modules, black was identified as the common module and yielded a novel key regulatory gene, CsPrx73. Transgenic cucumber plants overexpressing CsPrx73 enhance adventitious root (AR) formation under waterlogging conditions and increase reactive oxygen species (ROS) scavenging. Silencing of CsPrx73 expression by virus-induced gene silencing adversely affects AR formation under the waterlogging condition. Our results also indicated that CsERF7-3, a waterlogging-responsive ERF transcription factor, can directly bind to the ATCTA-box motif in the CsPrx73 promoter to initiate its expression. Overexpression of CsERF7-3 enhanced CsPrx73 expression and AR formation. On the contrary, CsERF7-3-silenced plants decreased CsPrx73 expression and rooting ability. In conclusion , our study demonstrates a novel CsERF7-3-CsPrx73 module that allows cucumbers to adapt more efficiently to waterlogging stress by promoting AR production and ROS scavenging.

Atypical architectural distortion detection in digital breast tomosynthesis: a multi-view computer-aided detection model with ipsilateral learning.

Objective.Breast architectural distortion (AD), a common imaging symptom of breast cancer, is associated with a particularly high rate of missed clinical detection. In clinical practice, atypical ADs that lack an obvious radiating appearance constitute most cases, and detection models based on single-view images often exhibit poor performance in detecting such ADs. Existing multi-view deep learning methods have overlooked the correspondence between anatomical structures across different views.Approach.To develop a computer-aided detection (CADe) model for AD detection that effectively utilizes the craniocaudal (CC) and mediolateral oblique (MLO) views of digital breast tomosynthesis (DBT) images, we proposed an anatomic-structure-based multi-view information fusion approach by leveraging the related anatomical structure information between these ipsilateral views. To obtain a representation that can effectively capture the similarity between ADs in images from ipsilateral views, our approach utilizes a Siamese network architecture to extract and compare information from both views. Additionally, we employed a triplet module that utilizes the anatomical structural relationship between the ipsilateral views as supervision information.Main results.Our method achieved a mean true positive fraction (MTPF) of 0.05-2.0, false positives (FPs) per volume of 64.40%, and a number of FPs at 80% sensitivity (FPs@0.8) of 3.5754; this indicates a 6% improvement in MPTF and 16% reduction in FPs@0.8 compared to the state-of-the-art baseline model.Significance.From our experimental results, it can be observed that the anatomic-structure-based fusion of ipsilateral view information contributes significantly to the improvement of CADe model performance for atypical AD detection based on DBT. The proposed approach has the potential to lead to earlier diagnosis and better patient outcomes.

Enhanced mechanical strength of a highly de-lithiated single-crystal Ni-rich cathode to suppress irreversible planar gliding.

The mechanical properties of de-lithiated single-crystal Ni-rich cathodes are causing extensive concern. Here, we first show that the compression hardness of single crystal Ni-rich cathode particles decreases significantly at highly de-lithiated states by micro-compression testing. Thus, phase-boundary hardening was introduced to inhibit the planar gliding, resulting in excellent electrochemical performance.

A CsEIL3-CsARN6.1 module promotes waterlogging-triggered adventitious root formation in cucumber by activating the expression of CsPrx5.

The formation of adventitious roots (ARs) derived from hypocotyl is the most important morphological adaptation to waterlogging stress in Cucumis sativus (cucumber). Our previous study showed that cucumbers with the gene CsARN6.1, encoding an AAA ATPase domain-containing protein, were more tolerant to waterlogging through increased AR formation. However, the apparent function of CsARN6.1 remained unknown. Here, we showed that the CsARN6.1 signal was predominantly observed throughout the cambium of hypocotyls, where de novo AR primordia are formed upon waterlogging treatment. The silencing of CsARN6.1 expression by virus-induced gene silencing and CRISPR/Cas9 technologies adversely affects the formation of ARs under conditions of waterlogging. Waterlogging treatment significantly induced ethylene production, thus upregulating CsEIL3 expression, which encodes a putative transcription factor involved in ethylene signaling. Furthermore, yeast one-hybrid, electrophoretic mobility assay and transient expression analyses showed that CsEIL3 binds directly to the CsARN6.1 promoter to initiate its expression. CsARN6.1 was found to interact with CsPrx5, a waterlogging-responsive class-III peroxidase that enhanced H2 O2 production and increased AR formation. These data provide insights into understanding the molecular mechanisms of AAA ATPase domain-containing protein and uncover a molecular mechanism that links ethylene signaling with the formation of ARs triggered by waterlogging.

Atypical architectural distortion detection in digital breast tomosynthesis: a computer-aided detection model with adaptive receptive field.

Objective. In digital breast tomosynthesis (DBT), architectural distortion (AD) is a breast lesion that is difficult to detect. Compared with typical ADs, which have radial patterns, identifying a typical ADs is more difficult. Most existing computer-aided detection (CADe) models focus on the detection of typical ADs. This study focuses on atypical ADs and develops a deep learning-based CADe model with an adaptive receptive field in DBT.Approach. Our proposed model uses a Gabor filter and convergence measure to depict the distribution of fibroglandular tissues in DBT slices. Subsequently, two-dimensional (2D) detection is implemented using a deformable-convolution-based deep learning framework, in which an adaptive receptive field is introduced to extract global features in slices. Finally, 2D candidates are aggregated to form the three-dimensional AD detection results. The model is trained on 99 positive cases with ADs and evaluated on 120 AD-positive cases and 100 AD-negative cases.Main results. A convergence-measure-based model and deep-learning model without an adaptive receptive field are reproduced as controls. Their mean true positive fractions (MTPF) ranging from 0.05 to 4 false positives per volume are 0.3846 ± 0.0352 and 0.6501 ± 0.0380, respectively. Our proposed model achieves an MTPF of 0.7148 ± 0.0322, which is a significant improvement (p< 0.05) compared with the other two methods. In particular, our model detects more atypical ADs, primarily contributing to the performance improvement.Significance. The adaptive receptive field helps the model improve the atypical AD detection performance. It can help radiologists identify more ADs in breast cancer screening.

Anatomy-based characteristics of far-field SVC electrograms in right superior pulmonary veins after isolation.

Background. Far-field electrograms from superior vena cava (SVC) can be present in right superior pulmonary vein (RSPV) after pulmonary vein (PV) isolation. Objectives. To analyze the characteristics of far-field SVC potentials in RSPV after PV isolation and the local anatomy difference between patients with and without the potentials. Methods. Patients undergoing PV isolation were retrospectively reviewed, contrast-enhanced computed tomography (CT) was performed before procedure for observing the anatomical relationship between RSPV and SVC. The prevalence and characteristics of far-field SVC electrograms were described and compared to far-field left atrial potentials at the nearest point along the linear ablation lesion. The anatomical proximity of RSPV and SVC on a 2-dimensional horizontal CT view was compared between patients with and without far-field SVC potentials. Results. Far-field SVC electrograms were observed in 35/92(38%) patients with an amplitude of 0.24 ± 0.11 mV and a major deflection slope of 0.051 ± 0.036 mV, both significantly higher than far-field left atrial electrograms (p < .001). In patients with far-field SVC electrograms, 83% had connected RSPV-SVC, defined as distance between RSPV and SVC endocardium less than 3 mm at the layer of RSPV ostium roof, while in patients without far-field SVC electrograms, 70% had disconnected RSPV-SVC. Conclusions. Far-field SVC electrograms appeared in RSPV had a prevalence higher than previously reported and a sharper major deflection compared to far-field left atrial electrograms. Connected RSPV-SVC on CT was associated with the presence of far-field SVC electrograms.

Treatment of triple negative breast cancer by near infrared light triggered mild-temperature photothermal therapy combined with oxygen-independent cytotoxic free radicals.

Triple negative breast cancer (TNBC) is highly malignant and prone to recurrence and metastasis. Patients with TNBC usually have poor prognosis. Hence, it is urgent to develop new comprehensive treatments for TNBC. The combination of heat shock protein (HSP) inhibitor and the photothermal agent can reduce the temperature required to kill tumor cells, thus achieving mild-temperature photothermal therapy (PTT). Compared with traditional PTT, mild-temperature PTT not only decreases tumor thermoresistance introduced by the overexpression of HSP, but also reduces the damage to normal tissues. Meanwhile, Azo initiator 2,2-azobis[2-(2-imidazolin-2-yl) propane]-dihydroch-loride (AIPH) can be thermally decomposed to generate oxygen-independent free radicals. Herein, a new therapeutic multifunctional nanoplatform (M-17AAG-AIPH) by loading heat shock protein 90 (HSP90) inhibitor (17AAG) and AIPH incorporated into mesoporous polydopamine (MPDA) was successfully constructed for mild-temperature PTT combined with oxygen-independent cytotoxic free radicals against TNBC. Under 808 nm laser irradiation, the mild-temperature PTT arising from the combined effects of 17AAG and MPDA induced a rapid release and decomposition of AIPH, promoting the apoptosis of cancer cells in hypoxic microenvironments. Both in vitro and in vivo results showed that the designed nanoplatform can significantly inhibit tumor growth and provided an efficient new therapeutic strategy for TNBC. STATEMENT OF SIGNIFICANCE: There is still an urgent need for new strategies for the treatment of triple negative breast cancer (TNBC). In this work, we successfully constructed a new therapeutic multifunctional nanoplatform (M-17AAG-AIPH) by co-carrying heat shock protein 90 (HSP90) inhibitor (17AAG) and AIPH on mesoporous polydopamine (MPDA). MPDA owned good biocompatibility and outstanding photothermal-conversion ability. The loading of 17AAG can reduce the heat resistance of tumor cells via specifically inhibiting the activity of HSP90, so as to achieve mild-temperature PTT. Meanwhile, 17AAG and MPDA mediated mild-temperature PTT promoted the decomposition of AIPH into oxygen-independent cytotoxic free radicals. Both in vitro and in vivo results showed that M-17AAG-AIPH can significantly inhibit tumor growth and provided an efficient new therapeutic strategy for TNBC.

Single-cell genomics identifies distinct B1 cell developmental pathways and reveals aging-related changes in the B-cell receptor repertoire.

BACKGROUND: B1 cells are self-renewing innate-like B lymphocytes that provide the first line of defense against pathogens. B1 cells primarily reside in the peritoneal cavity and are known to originate from various fetal tissues, yet their developmental pathways and the mechanisms underlying maintenance of B1 cells throughout adulthood remain unclear. RESULTS: We performed high-throughput single-cell analysis of the transcriptomes and B-cell receptor repertoires of peritoneal B cells of neonates, young adults, and elderly mice. Gene expression analysis of 31,718 peritoneal B cells showed that the neonate peritoneal cavity contained many B1 progenitors, and neonate B cell specific clustering revealed two trajectories of peritoneal B1 cell development, including pre-BCR dependent and pre-BCR independent pathways. We also detected profound age-related changes in B1 cell transcriptomes: clear difference in senescence genetic program was evident in differentially aged B1 cells, and we found an example that a B1 subset only present in the oldest mice was marked by expression of the fatty-acid receptor CD36. We also performed antibody gene sequencing of 15,967 peritoneal B cells from the three age groups and discovered that B1 cell aging was associated with clonal expansion and two B1 cell clones expanded in the aged mice had the same CDR-H3 sequence (AGDYDGYWYFDV) as a pathogenically linked cell type from a recent study of an atherosclerosis mouse model. CONCLUSIONS: Beyond offering an unprecedent data resource to explore the cell-to-cell variation in B cells, our study has revealed that B1 precursor subsets are present in the neonate peritoneal cavity and dissected the developmental pathway of the precursor cells. Besides, this study has found the expression of CD36 on the B1 cells in the aged mice. And the single-cell B-cell receptor sequencing reveals B1 cell aging is associated with clonal expansion.

MicroRNA775 regulates intrinsic leaf size and reduces cell wall pectin levels by targeting a galactosyltransferase gene in Arabidopsis.

Plants possess unique primary cell walls made of complex polysaccharides that play critical roles in determining intrinsic cell and organ size. How genes responsible for synthesizing and modifying the polysaccharides in the cell wall are regulated by microRNAs (miRNAs) to control plant size remains largely unexplored. Here we identified 23 putative cell wall-related miRNAs, termed as CW-miRNAs, in Arabidopsis thaliana and characterized miR775 as an example. We showed that miR775 post-transcriptionally silences GALT9, which encodes an endomembrane-located galactosyltransferase belonging to the glycosyltransferase 31 family. Over-expression of miR775 and deletion of GALT9 led to significantly enlarged leaf-related organs, primarily due to increased cell size. Monosaccharide quantification, confocal Raman imaging, and immunolabeling combined with atomic force microscopy revealed that the MIR775A-GALT9 circuit modulates pectin levels and the elastic modulus of the cell wall. We also showed that MIR775A is directly repressed by the transcription factor ELONGATED HYPOCOTYL5 (HY5). Genetic analysis confirmed that HY5 is a negative regulator of leaf size that acts through the HY5-MIR775A-GALT9 repression cascade to control pectin levels. These findings demonstrate that miR775-regulated cell wall remodeling is an integral determinant of intrinsic leaf size in A. thaliana. Studying other CW-miRNAs would provide more insights into cell wall biology.

Detecting the Early Infarct Core on Non-Contrast CT Images with a Deep Learning Residual Network.

PURPOSE: To explore a new approach mainly based on deep learning residual network (ResNet) to detect infarct cores on non-contrast CT images and improve the accuracy of acute ischemic stroke diagnosis. METHODS: We continuously enrolled magnetic resonance diffusion weighted image (MR-DWI) confirmed first-episode ischemic stroke patients (onset time: less than 9 h) as well as some normal individuals in this study. They all underwent CT plain scan and MR-DWI scan with same scanning range, layer thickness (4 mm) and interlayer spacing (4 mm) (The time interval between two examinations: less than 4 h). Setting MR-DWI as gold standard of infarct core and using deep learning ResNet combined with a maximum a posteriori probability (MAP) model and a post-processing method to detect the infarct core on non-contrast CT images. After that, we use decision curve analysis (DCA) establishing models to analyze the value of this new method in clinical practice. RESULTS: 116 ischemic stroke patients and 26 normal people were enrolled. 58 patients were allocated into training dataset and 58 were divided into testing dataset along with 26 normal samples. The identification accuracy of our ResNet based approach in detecting the infarct core on non-contrast CT is 75.9%. The DCA shows that this deep learning method is capable of improving the net benefit of ischemic stroke patients. CONCLUSIONS: Our deep learning residual network assisted with optimization methods is able to detect early infarct core on non-contrast CT images and has the potential to help physicians improve diagnostic accuracy in acute ischemic stroke patients.

The PIF1-miR408-PLANTACYANIN repression cascade regulates light-dependent seed germination.

Light-dependent seed germination is a vital process for many seed plants. A decisive event in light-induced germination is degradation of the central repressor PHYTOCHROME INTERACTING FACTOR 1 (PIF1). The balance between gibberellic acid (GA) and abscisic acid (ABA) helps to control germination. However, the cellular mechanisms linking PIF1 turnover to hormonal balancing remain elusive. Here, employing far-red light-induced Arabidopsis thaliana seed germination as the experimental system, we identified PLANTACYANIN (PCY) as an inhibitor of germination. It is a blue copper protein associated with the vacuole that is both highly expressed in mature seeds and rapidly silenced during germination. Molecular analyses showed that PIF1 binds to the miR408 promoter and represses miR408 accumulation. This in turn posttranscriptionally modulates PCY abundance, forming the PIF1-miR408-PCY repression cascade for translating PIF1 turnover to PCY turnover during early germination. Genetic analysis, RNA-sequencing, and hormone quantification revealed that PCY is necessary and sufficient to maintain the PIF1-mediated seed transcriptome and the low-GA-high-ABA state. Furthermore, we found that PCY domain organization and regulation by miR408 are conserved features in seed plants. These results revealed a cellular mechanism whereby PIF1-relayed external light signals are converted through PCY turnover to internal hormonal profiles for controlling seed germination.

Exploring Spatially Non-Stationary and Scale-Dependent Responses of Ecosystem Services to Urbanization in Wuhan, China.

Ecosystem services (ESs) are facing challenges from urbanization processes globally. Exploring how ESs respond to urbanization provides valuable information for ecological protection and urban landscape planning. Previous studies mainly focused on the global and single-scaled responses of ESs but ignored the spatially heterogenous and scale-dependent characteristics of these responses. This study chose Wuhan City in China as the study area to explore the spatially varying and scale-dependent responses of ESs, i.e., grain productivity, carbon sequestration, biodiversity potential and erosion prevention, to urbanization using geographically weighted regression (GWR). The results showed that the responses of ESs were spatially nonstationary evidenced by a set of local parameter estimates in GWR models, and scale-dependent indicated by two kinds of scale effects: effect of different bandwidths and effect of grid scales. The stationary index of GWR declined rapidly as the bandwidth increased until reaching to a distance threshold. Moreover, GWR outperformed ordinary least square at both grid scales (i.e., 5 km and 10 km scales) and behaved better at finer scale. The spatially non-stationary and scale-dependent responses of ESs to urbanization are expected to provide beneficial guidance for ecologically friendly urban planning.

Mechanisms of Waterlogging Tolerance in Plants: Research Progress and Prospects.

Waterlogging is one of the main abiotic stresses suffered by plants. Inhibition of aerobic respiration during waterlogging limits energy metabolism and restricts growth and a wide range of developmental processes, from seed germination to vegetative growth and further reproductive growth. Plants respond to waterlogging stress by regulating their morphological structure, energy metabolism, endogenous hormone biosynthesis, and signaling processes. In this updated review, we systematically summarize the changes in morphological structure, photosynthesis, respiration, reactive oxygen species damage, plant hormone synthesis, and signaling cascades after plants were subjected to waterlogging stress. Finally, we propose future challenges and research directions in this field.

Transcriptome profiling reveals key genes related to astringency during cucumber fruit development.

The goal of this study was to provide quantitative data on the catechin contents and underlying molecular regulatory mechanisms in cucumber during fruit development. The dynamic changes in the total catechin contents and RNA-seq-based transcriptome profiling of the flesh and peel of the cucumber cultivar 'YanBai', which is strongly astringent, were examined at three key developmental stages 3, 6 and 9 days post-pollination. The total catechin content decreased as cucumber fruit developed and was significantly lower in the flesh than in the peel. In total, 5092 and 4004 genes were found to be differently expressed in the peel and flesh, respectively. Based on a functional annotation, eight structural genes encode enzymes involved in the catechin biosynthesis pathway. Three genes encoding 4-coumarate-CoA ligases, two genes encoding chalcone isomerases, two genes encoding dihydroflavonol-4-reductase and one gene each encoding a phenylalanine ammonia-lyase, flavanone 3-hydroxylase and cinnamate 4-hydroxylase were identified as affecting the catechin content of cucumber. The transcriptome data also revealed the significance of transcription factors, including WD40-repeat proteins, MYB and bHLH, in regulating catechin biosynthesis. These findings help increase our understanding of the molecular mechanisms controlling catechin biosynthesis and astringency development in cucumber fruit.

Small RNA sequencing identifies cucumber miRNA roles in waterlogging-triggered adventitious root primordia formation.

The formation of adventitious roots (ARs) is a key morphological adaptation of cucumber (Cucumis sativus L.) to waterlogging stress. MicroRNAs (miRNAs) constitute a group of non-coding small RNAs (sRNA) that play crucial roles in regulating diverse biological processes, including waterlogging acclimation. However, which specific miRNAs and how they are involved in waterlogging-triggered de novo AR primordia formation are not fully known. Here, Illumina sRNA sequencing was applied to sequence six sRNA libraries generated from the waterlogging-tolerant cucumber Zaoer-N after 48 h of waterlogging and the control. A total of 358 cucumber miRNAs, 312 known and 46 novel, were obtained. Among them, 23 were differentially expressed, with 10 and 13 being up- and downregulated, respectively. A qPCR expression study confirmed that the identified differentially expressed miRNAs were credible. A total of 657 putative miRNA target genes were predicted for the 23 miRNAs using an in silico approach. A gene ontology enrichment analysis revealed that target genes functioning in cell redox homeostasis, cytoskeleton, photosynthesis and cell growth were over-represented. In total, 58 of the 657 target genes showed inverse expression patterns compared with their respective miRNAs through a combined analysis of sRNA- and RNA-sequencing-based transcriptome datasets using the same experimental design. The target gene annotation included a peroxidase, a GDSL esterases/lipase and two heavy metal-associated isoprenylated plant proteins. Our results provide an important framework for understanding the unique miRNA patterns seen in responses to waterlogging and the miRNA-mediated formation of de novo AR primordia in cucumber.

Slow-Growing Thalamic Glioma with Histone H3 Lysine 27-to-Methionine Mutation: 3-Year Follow-Up Before Surgical Intervention.

BACKGROUND: The 2016 World Health Organization Classification of Tumours of the Central Nervous System was revised to include a new diagnostic entity, diffuse midline glioma, H3 K27M-mutant (DMG-K27M), a highly aggressive tumor with a mean survival time of 1 year after diagnosis. DMG-K27M is classified as a World Health Organization grade IV tumor regardless of histopathologic features, and there is currently no effective treatment for it despite ongoing research. CASE DESCRIPTION: We present a case of a 39-year-old man with a slow-growing thalamic glioma with histone H3 lysine 27-to-methionine mutation. This patient received surgical intervention 3 years after the initial discovery of the tumor. Because the patient did not receive any preoperative treatment for DMG-K27M, this case reflects 1 possible natural course of progression for this type of malignancy. CONCLUSIONS: There are currently no effective therapeutic options for treatment of DMG-K27M. The slow tumor growth and prolonged survival time (≥ 3 years) in the absence of intervention in this case serve as a reminder that much is still not known about histone H3 lysine 27-to-methionine mutation and how it impacts the pathophysiology, diagnosis, treatment, and prognosis of the disease. Careful evaluation is warranted to determine if early intervention is the best approach when treating DMG-K27M.

Overexpression of microRNA408 enhances photosynthesis, growth, and seed yield in diverse plants.

The ability of a plant to produce grain, fruit, or forage depends ultimately on photosynthesis. There have been few attempts, however, to study microRNAs, which are a class of endogenous small RNAs post-transcriptionally programming gene expression, in relation to photosynthetic traits. We focused on miR408, one of the most conserved plant miRNAs, and overexpressed it in parallel in Arabidopsis, tobacco, and rice. The transgenic plants all exhibited increased copper content in the chloroplast, elevated abundance of plastocyanin, and an induction of photosynthetic genes. By means of gas exchange and optical spectroscopy analyses, we showed that higher expression of miR408 leads to enhanced photosynthesis through improving efficiency of irradiation utilization and the capacity for carbon dioxide fixation. Consequently, miR408 hyper-accumulating plants exhibited higher rate of vegetative growth. An enlargement of seed size was also observed in all three species overproducing miR408. Moreover, we conducted a 2-year-two-location field trial and observed miR408 overexpression in rice significantly increased yield, which was primarily attributed to an elevation in grain weight. Taken together, these results demonstrate that miR408 is a positive regulator of photosynthesis and that its genetic engineering is a promising route for enhancing photosynthetic performance and yield in diverse plants.

Computed tomography perfusion and computed tomography angiography for prediction of clinical outcomes in ischemic stroke patients after thrombolysis.

Cerebral blood perfusion and cerebrovascular lesions are important factors that can affect the therapeutic efficacy of thrombolysis. At present, the majority of studies focus on assessing the accuracy of lesion location using imaging methods before treatment, with less attention to predictions of outcomes after thrombolysis. Thus, in the present study, we assessed the efficacy of combined computed tomography (CT) perfusion and CT angiography in predicting clinical outcomes after thrombolysis in ischemic stroke patients. The study included 52 patients who received both CT perfusion and CT angiography. Patients were grouped based on the following criteria to compare clinical outcomes: (1) thrombolytic and non-thrombolytic patients, (2) thrombolytic patients with CT angiography showing the presence or absence of a vascular stenosis, (3) thrombolytic patients with CT perfusion showing the presence or absence of hemodynamic mismatch, and (4) different CT angiography and CT perfusion results. Short-term outcome was assessed by the 24-hour National Institution of Health Stroke Scale score change. Long-term outcome was assessed by the 3-month modified Rankin Scale score. Of 52 ischemic stroke patients, 29 were treated with thrombolysis and exhibited improved short-term outcomes compared with those without thrombolysis treatment (23 patients). Patients with both vascular stenosis and blood flow mismatch (13 patients) exhibited the best short-term outcome, while there was no correlation of long-term outcome with CT angiography or CT perfusion findings. These data suggest that combined CT perfusion and CT angiography are useful for predicting short-term outcome, but not long-term outcome, after thrombolysis.

Segmentation of peritumoral oedema offers a valuable radiological feature of cerebral metastasis.

OBJECTIVE: Peritumoral oedema (PTO) is commonly observed on MRI in malignant brain tumours including brain metastasis (bMET) and glioblastoma multiforme (GBM). This study aimed to differentiate bMET from GBM by comparing the volume ratio of PTO to tumour lesion (Rvol). METHODS: 56 patients with solitary bMET or GBM were enrolled, and MRI was analyzed by a semi-automatic methodology based on MATLAB (Mathworks, Natick, MA). The PTO volume (Voedema) was segmented for quantification using T2 fluid-attenuated inversion-recovery images, while the tumour volume was quantified with enhanced T1 images. The quantitative volume of the tumour, PTO and the ratio of PTO to tumour were interpreted using SPSS(®) (IBM Corp., New York, NY; formerly SPSS Inc., Chicago, IL) by considering different locations and pathologies. RESULTS: The tumour volumes of supratentorial GBM, supratentorial bMET (supra-bMET) and infratentorial bMET were 32.22 ± 21.9, 18.45 ± 17.28 and 11.40 ± 5.63 ml, respectively. The corresponding Voedema were 44.08 ± 25.84, 73.20 ± 40.35 and 23.74 ± 7.78 ml, respectively. The Voedema difference between supratentorial and infratentorial lesions is significant (p-value = 0.002). Supra-bMET has a smaller tumour volume (p-value = 0.032), but a larger PTO (p-value = 0.007). The ratio of Voedema to the tumour volume in bMET is statistically higher than that in GBM (p-value = 0.015). The cut-off ratio for identifying bMET from GBM is 3.9, with a specificity and sensitivity of 90.0% and 68.8%, respectively. CONCLUSION: Segmentation is an efficient method to quantify irregular PTO. bMET possesses more extensive oedema with smaller tumour volume than does GBM. The Rvol is a valuable index to distinguish bMET from GBM. ADVANCES IN KNOWLEDGE: This study presents a new method for the quantitation of PTO to differentiate bMET from GBM.