Purpose:Investigate the threshold setting and accuracy of CTP in predicting the infarct core volume of acute ischemic stroke.
Material and method:43 acute ischemic stroke patients admitted to the ...Department of Neurology of the First Hospital of Jilin university underwent Intra-arterial therapy from 2017.1 to 2017.12, and were retrospectively analyzed. Multimodal CT perfusion were examined prior to therapy, and non-contrast CT(NCCT) or MRI were reexamined 2-14 days after onset. Based on the mTICI following DSA intervention, the subjects were further categorized into recanalization positive group(mTICI 2b-3) and recanalization negative group(mTICI<2b). The infarct core volume was predicted via the MTT/CBV dual-threshold by CTP(Threshold setting: MTT>145%; 7 thresholds for CBV with an interval of 0.5, ranging between 2.0-5.0). The final infarct volume(FIV) was determined by follow up NCCT or MRI, and the difference of FIV was analyzed between the recanalization positive group and the recanalization negative group.
Results:The FIV and the predicted infarct core volumes were compared among all patients. The predicted volumes by threshold 3 (Z=1.717, p=0.086), threshold 4(Z=0.110, p=0.912) and threshold 5(Z=1.678, p= 0.093 ) were close to the FIV. However, the difference compared to FIV did not differ significantly among threshold 3, 4and5.The predicted volumes by threshold 2 (Z=1.882, p=0.060), threshold 3(Z=0.154, p=0.877) and threshold 4(Z=1.471, p=0.141) were close to the FIV in the recanalization-positive group.
The difference analysis of threshold 2, 3 and 4 revealed closest prediction of threshold 2, with a median volume of 32.61(19.20~61.74).However, the difference compared to FIV did not differ significantly among threshold 2, 3 and 4.The predicted volumes by threshold threshold 5(Z=1.156, p=0.248), threshold 6(Z=0.800, p=0.424) and threshold 7(Z= 0.267, p=0.790) were close to the FIV in the recanalization-negative group.The difference analysis of threshold 5, 6 and 7 revealed closest prediction of threshold 7, with a median volume of 20.92(11.88~110.63). However, the difference compared to FIV did not differ significantly among threshold 5, 6 and 7.
Conclusions: CTP predicted infarct core volume in AIS is highly correlated to FIV. More precise predictions might be achieved via adopting dynamic parameter thresholds based on the state of recanalization.
BACKGROUNDTreatment decision making is strictly associated with the outcomes in patients with ischemic stroke who show a large core infarct. Medical care alone may result in suboptimal treatment ...efficacy, and endovascular treatment may be accompanied by safety issues. Whether endovascular treatment is superior to medical care is not well investigated in the clinical studies. AIMTo investigate the efficacy of endovascular treatment and drug therapy alone in mild ischemic stroke patients with large infarct cores. METHODSFifty patients with mild ischemic stroke and 50 patients with acute ischemic stroke caused by anterior large vessel occlusion were selected at the First Affiliated Hospital of Hebei North University between January 2021 and December 2021. Patients were divided into an endovascular therapy group and a drug therapy group according to different treatment methods. In the endovascular therapy group, there were 28 patients with minor stroke and 22 patients with large infarct cores. The drug therapy group had 22 patients with minor stroke and 28 patients with large infarct cores. The National Institutes of Health Stroke Scale (NIHSS) scores were collected and compared between the two groups immediately after the operation and 24 h and 7 d after the operation. The modified Rankin scale (mRS) and/or activity of daily living were assessed at hospital discharge. RESULTSThere was no significant difference in NIHSS scores between the two groups before the operation (P > 0.05). NIHSS scores were lower in the endovascular therapy group than in the drug therapy group at 24 h and 7 d after the operation and at hospital discharge (all P < 0.05). The incidence of early neurologic deterioration was significantly lower in the endovascular therapy group than in the drug therapy group (P < 0.05). At hospital discharge, the mRS score was lower in the endovascular treatment group than in the drug therapy group, and the activity of daily living score was better in the endovascular treatment group than in the drug therapy group (all P < 0.05). During a follow-up of 3 mo, 17 patients (34.0%) had good prognosis (mRS ≤ 2), 33 patients (66.0%) had poor prognosis (mRS > 2), and 11 patients (22.0%) died. In the medical treatment group, 16 patients (mRS ≤ 2) had good prognosis (32.0%), 34 patients (mRS > 2) had poor prognosis (68.0%), and 14 patients (28.0%) died. There was no significant difference in prognosis and mortality between the two groups (P > 0.05). CONCLUSIONEndovascular therapy can improve NIHSS score and mRS score in patients with mild ischemic stroke and large infarct cores. It is suitable for clinical application.
Purpose: The purpose of our work is to present a method that utilizes high-quality non-contrast CT (NCCT) images to reduce the noise of CT perfusion (CTP) baseline images to improve the visibility of ...infarct core in cerebral blood volume (CBV) maps.
Methods: First, a theoretical analysis of the CTP imaging system was performed to demonstrate that for both deconvolution- and non-deconvolution-based CTP systems. The noise of CBV maps is profoundly influenced by the baseline image noise. Consequently, baseline noise reduction is extremely effective in improving the contrast-to-noise ratio (CNR) of ischemic lesions in CBV maps. Second, a method was proposed to fuse the freely available NCCT images with the original CTP baseline images. An optimal weighting scheme was derived such that the noise of the fused baseline image is minimized. Third, the impact of the proposed NCCT-baseline fusion method was investigated using five in vivo canine subjects with different infarct core sizes. NCCT and CTP scans were performed following a clinical stroke CT imaging protocol using a 64-slice MDCT. Two of the subjects also received a diffusion-weighted imaging scan using a 3T-MRI scanner to establish the reference diagnosis for the infarct core.
Results: For all five canine subjects, the proposed method led to lower CBV noise and better conspicuity of the infarct core. Compared with a standard CTP postprocessing method, the proposed method reduced the CBV noise standard deviation by 70 % ± 24 % and increased the CNR of infarct core by 23 % ± 11 % (p < 0.01).
Conclusions: By utilizing the high-quality NCCT images to reduce CTP baseline image noise, the quality of CBV maps and the conspicuity of ischemic infarct core can be effectively improved. The proposed method can be readily implemented with minimal interruption to the existing clinical workflow.
Purpose
Thrombolytic therapy in patients with acute ischemic stroke is contraindicated when the infarction core exceeds a given threshold. To date, there are no standardized guidelines for computed ...tomography infarction core assessment. Current practice involves use of thresholding methods, where the results are further adjusted by an experienced physician. An automated method for infarction core delineation and volume measurement was developed and tested.
Materials and methods
CT postprocessing software was developed for analysis of whole brain perfused blood volume (PBV) and cerebral blood volume (CBV) maps. The program was designed for potential use with mean transit time (MTT) or cerebral blood flow (CBF) maps. The proposed method was tested on a set of 12 patients on both PBV and CBV maps with whole brain coverage by comparison with the results of a simple thresholding method and with manually marked findings provided by two independent physicians.
Results
The proposed method produced a marked infarct core volume corresponding to 53 % of the manually delineated volumes. The simple thresholding method with the optimal threshold, using the same dataset, marked 15
larger volume compared to the volume delineated by physicians.
Conclusion
An automated infarction core segmentation method based on local neighborhood features was developed and tested, demonstrating its utility in distinguishing between infarcted and non-infarcted areas, as well as reduction in the number of false positives and volume error.
Supratentorial cerebral infarction can cause functional inhibition of remote regions such as the cerebellum, which may be relevant to diaschisis. This phenomenon is often analyzed using positron ...emission tomography and single photon emission CT. However, these methods are expensive and radioactive. Thus, the present study quantified the changes of infarction core and remote regions after unilateral middle cerebral artery occlusion using apparent diffusion coefficient values. Diffu- sion-weighted imaging showed that the area of infarction core gradually increased to involve the cerebral cortex with increasing infarction time. Diffusion weighted imaging signals were initially in- creased and then stabilized by 24 hours. With increasing infarction time, the apparent diffusion co- efficient value in the infarction core and remote bilateral cerebellum both gradually decreased, and then slightly increased 3-24 hours after infarction. Apparent diffusion coefficient values at remote regions （cerebellum） varied along with the change of supratentorial infarction core, suggesting that the phenomenon of diaschisis existed at the remote regions. Thus, apparent diffusion coefficient values and diffusion weighted imaging can be used to detect early diaschisis.
This article describes our upcoming scientific database medical system together with the two examples of its application. The idea of the experimental system is to process and store the amount of ...heterogeneous multimedia data objects for particular real neurological case studies with brain vascular diseases specialization and others, which can be used for the future medical research activities. The concept of the multilevel database structure is presented together with some present common data types and standards often used in medical applications (DICOM, DASTA and HL7). The article contains examples of system application in our biomedical research, the brain infarction core evaluation and the liver's vascular tree extraction. Key words: Medical Database, DICOM, HL7, Infarction Core
Stroke causes 9% of all deaths around the world and is the second most common cause of death after ischemic heart disease. Enhancing recovery from stroke and limiting ischemic damage are major goals ...to decrease stroke morbidity and mortality . Brain tissue is extremely sensitive to oxygen and glucose deprivation, and even brief ischemia can initiate a complex sequence of events that ultimately culminates in cellular death. Studies performed during the past 30 years have identified several key pathophysiological events that lead to ischemic neuronal degeneration. The pathophysiological processes in stroke are complex and involve disruption of the blood–brain barrier (BBB), energy failure, loss of cell ion homeostasis, acidosis, increased intracellular calcium levels, excitotoxicity, free radical-mediated toxicity, generation of arachidonic acid products, cytokine-mediated apoptosis, activation of glial cells, and infiltration of leukocytes . In focal cerebral ischemia, ischemic tissue is divided into an infarction core and penumbra. The core is the area of the brain where blood flow is reduced below 10–20% of its normal levels . In the core, rapid anoxic depolarization causes immediate loss of membrane potential followed by the loss of membrane integrity and rapid necrotic cell death. The penumbra is the tissue surrounding the core where the blood flow is partly preserved due to collateral circulation and diffusion .
PDF
