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- Maier, O., et al.
(författare)
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ISLES 2015-A public evaluation benchmark for ischemic stroke lesion segmentation from multispectral MRI
- 2017
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Ingår i: Medical Image Analysis. - : Elsevier BV. - 1361-8415 .- 1361-8423. ; 35, s. 250-269
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Tidskriftsartikel (refereegranskat)abstract
- Ischemic stroke is the most common cerebrovascular disease, and its diagnosis, treatment, and study relies on non-invasive imaging. Algorithms for stroke lesion segmentation from magnetic resonance imaging (MRI) volumes are intensely researched, but the reported results are largely incomparable due to different datasets and evaluation schemes. We approached this urgent problem of comparability with the Ischemic Stroke Lesion Segmentation (ISLES) challenge organized in conjunction with the MICCAI 2015 conference. In this paper we propose a common evaluation framework, describe the publicly available datasets, and present the results of the two sub-challenges: Sub-Acute Stroke Lesion Segmentation (SISS) and Stroke Perfusion Estimation (SPES). A total of 16 research groups participated with a wide range of state-of-the-art automatic segmentation algorithms. A thorough analysis of the obtained data enables a critical evaluation of the current state-of-the-art, recommendations for further developments, and the identification of remaining challenges. The segmentation of acute perfusion lesions addressed in SPES was found to be feasible. However, algorithms applied to sub-acute lesion segmentation in SISS still lack accuracy. Overall, no algorithmic characteristic of any method was found to perform superior to the others. Instead, the characteristics of stroke lesion appearances, their evolution, and the observed challenges should be studied in detail. The annotated ISLES image datasets continue to be publicly available through an online evaluation system to serve as an ongoing benchmarking resource (www.isles-challenge.org).
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| 2. |
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| 3. |
- Li, Xiang, et al.
(författare)
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A study on crown interception with four dominant tree species : A direct measurement
- 2016
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Ingår i: Hydrology Research. - : IWA Publishing. - 1998-9563 .- 0029-1277 .- 2224-7955. ; 47:4, s. 857-868
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Tidskriftsartikel (refereegranskat)abstract
- An experiment was conducted to concentrate on the rainfall interception process of individual trees for four common species in Beijing, China, which included needle species (Platycladus orientalis and Pinus tabulaeformis) and broadleaf species (Quercus variabilis and Acer truncatum). Two types of interception storages, the maximum (Cmax) and the minimum interception storage (Cmin), were examined at four simulated rainfall intensities (from 11.7 to 78.5 mm hr-1). Results showed that an average of 91% of Cmax for all the species was intercepted during the first 10 minutes of rainfall, while 45% of Cmax drained off after rainfall cessation. Leaf area index (LAI) and leaf area (LA) were significantly correlated (p < 0.05) with Cmax and Cmin, while such significant correlations were not found between rainfall intensity and Cmax and Cmin. Average Cmax and Cmin across all the species corresponded to 3 and 1% of gross rainfall. Mean Cmax and Cmin of the needle species were 3.0 and 1.8 times larger than that for the broadleaf ones. Results revealed that interception was a dynamic process which encompassed three phases. In addition, LAI and LA were valid predictors of interception in small trees, and deserve further test in forest stands.
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| 4. |
- Tatlisumak, Turgut, et al.
(författare)
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Comparison of Manual Cross-Sectional Measurements and Automatic Volumetry of the Corpus Callosum, and Their Clinical Impact: A Study on Type 1 Diabetes and Healthy Controls
- 2020
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Ingår i: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Degenerative change of the corpus callosum might serve as a clinically useful surrogate marker for net pathological cerebral impact of diabetes type 1. We compared manual and automatic measurements of the corpus callosum, as well as differences in callosal cross-sectional area between subjects with type 1 diabetes and healthy controls. Materials and methods: This is a cross-sectional study on 188 neurologically asymptomatic participants with type 1 diabetes and 30 healthy age- and sex-matched control subjects, recruited as part of the Finnish Diabetic Nephropathy Study. All participants underwent clinical work-up and brain MRI. Callosal area was manually measured and callosal volume quantified with FreeSurfer. The measures were normalized using manually measured mid-sagittal intracranial area and volumetric intracranial volume, respectively. Results: Manual and automatic measurements correlated well (callosal area vs. volume: ρ = 0.83, p < 0.001 and mid-sagittal area vs. intracranial volume: ρ = 0.82, p < 0.001). We found no significant differences in the callosal measures between cases and controls. In type 1 diabetes, the lowest quartile of normalized callosal area was associated with higher insulin doses (p = 0.029) and reduced insulin sensitivity (p = 0.033). In addition, participants with more than two cerebral microbleeds had smaller callosal area (p = 0.002). Conclusion: Manually measured callosal area and automatically segmented are interchangeable. The association seen between callosal size with cerebral microbleeds and insulin resistance is indicative of small vessel disease pathology in diabetes type 1. © Copyright © 2020 Claesson, Putaala, Shams, Salli, Gordin, Liebkind, Forsblom, Summanen, Tatlisumak, Groop, Martola and Thorn.
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