scholarly journals Pseudo-colour with K-means Clustering Algorithm for Acute Ischemic Stroke Lesion Segmentation in Brain MRI

2021 ◽  
Vol 29 (2) ◽  
Author(s):  
Abang Mohd Arif Anaqi Abang Isa ◽  
Kuryati Kipli ◽  
Ahmad Tirmizi Jobli ◽  
Muhammad Hamdi Mahmood ◽  
Siti Kudnie Sahari ◽  
...  

Segmentation of an acute ischemic stroke from a single modality of a greyscale magnetic resonance imaging (MRI) is an essential and challenging task. Recently, there are several numbers of related works on the automatic segmentation of infarct lesion from the input image and give a high accuracy in extraction of infarct lesion. Still, limited works have been reported in isolating the penumbra tissues and infarct core separately. The segmentation of the penumbra tissues is necessary because that region has the potential to recover. This paper presented an automated segmentation algorithm on diffusion-weighted magnetic resonance imaging (DW-MRI) image utilizing pseudo-colour conversion and K-means clustering techniques. A greyscale image contains only intensity information and often misdiagnosed due to overlap intensity of an image. Colourization is the method of adding colours to greyscale images which allocate luminance or intensity for red, green, and blue channels. The greyscale image is converted to pseudo-colour is to intensify the visual perception and deliver more information. Then, the algorithm segments the region of interest (ROI) using K-means clustering. The result shows the potential of automated segmentation to differentiate between the healthy and lesion tissues with 90.08% in accuracy and 0.89 in dice coefficient. The development of an automated segmentation algorithm was successfully achieved by entirely depending on the computer with minimal interaction.

2020 ◽  
Vol 9 (20) ◽  
Author(s):  
Hwan Lee ◽  
Yifeng Yang ◽  
Baoqiong Liu ◽  
Simon A. Castro ◽  
Tiantian Shi

Background Use of inpatient brain magnetic resonance imaging (MRI) in patients with acute ischemic stroke is highly institution dependent and has been associated with increased length and cost of hospital stay. We examined whether inpatient brain MRI in patients with acute ischemic stroke is associated with improved clinical outcomes to justify its resource requirements. Methods and Results The National Inpatient Sample database was queried retrospectively to find 94 003 patients who were admitted for acute ischemic stroke and then received inpatient brain MRI between 2012 and 2014. Multivariable regression analysis was performed with respect to a control group to assess for differences in the rates of inpatient mortality and complications, as well as the length and cost of hospital stay based on brain MRI use. Inpatient brain MRI was independently associated with lower rates of inpatient mortality (1.67% versus 3.09%; adjusted odds ratio [OR], 0.60; 95% CI, 0.53–0.68; P <0.001), gastrostomy (2.28% versus 2.89%; adjusted OR, 0.82; 95% CI, 0.73–0.93; P <0.001), and mechanical ventilation (1.97% versus 2.82%; adjusted OR, 0.68; 95% CI, 0.60–0.77; P <0.001). Brain MRI was independently associated with ≈0.32 days (8%) and $1131 (11%) increase in the total length ( P <0.001) and cost ( P <0.001) of hospital stay, respectively. Conclusions Inpatient brain MRI in patients with acute ischemic stroke is associated with substantial decrease in the rates of inpatient mortality and complications, at the expense of marginally increased length and cost of hospitalization.


2002 ◽  
Vol 42 (7) ◽  
pp. 281-288
Author(s):  
Keisuke MARUYAMA ◽  
Tsuneyoshi EGUCHI ◽  
Shigeo SORA ◽  
Masafumi IZUMI ◽  
Hirofumi HIYAMA ◽  
...  

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Xiangyan Chen ◽  
Lu Zheng ◽  
Jia LI ◽  
Wenjie Yang

Backgrounds: The purpose of this study was to investigate vessel wall features visualization by high resolution magnetic resonance imaging (HRMRI) in a series of ischemic stroke patients and to identify differences between lesions in the anterior and posterior circulation. Methods: We consecutively recruited Chinese patients with acute ischemic stroke or transient ischemic attack from 2016 to 2018. All patients were scanned at 3T magnetic resonance imaging. We evaluated pre-and post-contrast cross-sectional views of M1 and M2 segments of middle cerebral arteries (MCAs), basilar arteries (BA) and V4 segments of vertebral arteries (VAs). Results: A total of 74 patients (males 52.3%; median age 62 years old) were included in this study, among which, 234 lesions were identified on HRMRI, including 117 MCA lesions, 26 BA lesions, and 91 VA lesions. The sensitivity and specificity of MRA for diagnosing stenosis in anterior circulation were 89.3% (95% CI, 81.8%- 94.2%) and 50.0 (95% CI, 9.2%- 90.8%). The sensitivity and specificity of MRA for diagnosing stenosis in posterior circulation were 73.2% (95% CI, 63.9%- 80.9%) and 40.0 (95% CI, 7.3%- 83.0%). VA had a significantly higher contrast enhancement index (43.71± 7.74, p <0.016) than MCA (23.32± 2.46) or BA (22.69± 5.31) . Anterior circulation plaques had higher degree of stenosis (anterior versus posterior: 68.5% vs. 62.9%, p =0.036), more eccentric distribution (anterior versus posterior: 70.1% versus 53.8%, p =0.015) and higher rate of intraplaque hemorrhage (anterior versus posterior: 17.1% versus 7.7%, p =0.046). The plaques in posterior circulation had a thicker lesion wall (posterior versus anterior 16.58± 8.25 mm 2 vs. 9.10± 4.07 mm 2 , p <0.001) and higher enhancement index (posterior versus anterior 39.04± 8.50 vs. 23.32± 2.46, p <0.001) than the plaques in anterior circulation. Conclusions: The lesions in posterior circulations could be obscure on MRA. The area stenosis, intraplaque hemorrhage and enhancement index differed between circulations.


Stroke ◽  
2020 ◽  
Vol 51 (7) ◽  
pp. 2240-2243
Author(s):  
Zien Zhou ◽  
Sohei Yoshimura ◽  
Candice Delcourt ◽  
Richard I. Lindley ◽  
Shoujiang You ◽  
...  

Background and Purpose: To determine factors associated with fluid-attenuated inversion recovery (FLAIR) hyperintense arteries (FLAIR-HAs) on magnetic resonance imaging and their prognostic significance in thrombolysis-treated patients with acute ischemic stroke from the ENCHANTED (Enhanced Control of Hypertension and Thrombolysis Stroke Study) trial alteplase-dose arm. Methods: Patients with acute ischemic stroke (N=293) with brain magnetic resonance imaging (FLAIR and diffusion-weighted imaging sequences) scanned <4.5 hours of symptom onset were assessed for location and extent (score) of FLAIR-HAs, infarct volume, large vessel occlusion (LVO), and other ischemic signs. Logistic regression models were used to determine predictors of FLAIR-HAs and the association of FLAIR-HAs with 90-day outcomes: favorable functional outcome (primary; modified Rankin Scale scores, 0–1), other modified Rankin Scale scores, and intracerebral hemorrhage. Results: Prior atrial fibrillation, LVO, large infarct volume, and anterior circulation infarction were independently associated with FLAIR-HAs. The rate of modified Rankin Scale scores 0 to 1 was numerically lower in patients with FLAIR-HAs versus without (69/152 [45.4%] versus 75/131 [57.3%]), as was the subset of LVO (37/93 [39.8%] versus 9/16 [56.3%]), but not in those without LVO (25/36 [69.4%] versus 60/106 [56.6%]). After adjustment for covariables, FLAIR-HAs were independently associated with increased primary outcome (adjusted odds ratio [95% CI]: overall 4.14 [1.63–10.50]; with LVO 4.92 [0.87–27.86]; no LVO 6.16 [1.57–24.14]) despite an increased risk of hemorrhagic infarct (4.77 [1.12–20.26]). Conclusions: FLAIR-HAs are more frequent in acute ischemic stroke with cardioembolic features and indicate potential for a favorable prognosis in thrombolysis-treated patients possibly mediated by LVO. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01422616.


Stroke ◽  
2014 ◽  
Vol 45 (8) ◽  
pp. 2330-2334 ◽  
Author(s):  
Sarah Power ◽  
Charles Matouk ◽  
Leanne K. Casaubon ◽  
Frank L. Silver ◽  
Timo Krings ◽  
...  

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