scholarly journals STUDY OF SIGNIFICANCE OF PHASE MASK IMAGE IN ACUTE STROKE PATIENTS

2022 ◽  
Vol 8 (1) ◽  
pp. 6-10
Author(s):  
Krishna Teja Nerella ◽  
Dileep Reddy Ayapaneni ◽  
Surekha Srikonda

Background: Phase images contains information regarding local susceptibility changes between the tissues, which can help measure the iron and other content which changes the local field. Typically, this information is ignored before looking at console. Susceptibility weighted imaging (SWI) is a magnetic resonance (MR) technique detects an early hemorrhagic transformation within the infarct to provide insight into cerebral hemodynamics following the stroke. Objective: Significance of “phase mask imaging in differentiation of hemorrhage and calcifications” in acute stroke patients. Methods: An observational non-interventional study carried out on 100 patients with stroke and headache symptoms. MRI Brain Stroke Profile with FLAIR, DWI, ADC, SWAN, and Phase mask sequences, done on 3T GE MRI scanner. Results: All patients underwent MRI study with SWI sequence. Of 183 cases, 33%(n=60) patients had microbleeds, 5%(n=10) patients had granulomas, 32%(n=58) patients had arterial thrombus with infarct, 11%(n=20) patients had falx calcifications, 11%(n=20) patients had intraparenchymal haemorrhage, and 8%(n=15) patients had infarcts with haemorrhagic transformation. The sensitivity of phase imaging in the detection of calcification was 90%. Conclusion: Phase mask imaging plays an important role to detect intracranial calcifications and chronic microbleeds. Phase mask imaging acts as a supplement tool in acute stroke patients, which guides further management.

2005 ◽  
Vol 19 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Jens Fiehler ◽  
Christian Remmele ◽  
Thomas Kucinski ◽  
Michael Rosenkranz ◽  
Götz Thomalla ◽  
...  

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Sundeep Saini ◽  
Steven Warach ◽  
Marie Luby ◽  

Objectives: Hemorrhagic transformation of the ischemic lesion is a common thrombolytic complication when treating acute stroke patients with standard IV-tPA. In a retrospective study we demonstrated that patients that have HT post-thrombolysis have a significantly lowered cerebral blood volume (CBV) on their pre-thrombolysis MRI compared to non HT patients. The objective of this study was to determine prospectively whether reduced CBV in combination with stroke severity can predict the occurrence of HT in patients post-thrombolysis. Methods: Patients were selected from the NINDS Stroke Registry if they: had an acute ischemic stroke located in the MCA territory, were treated with standard IV-tPA, had a pre-treatment MRI with evaluable DWI and PWI, and had post-treatment MRI evaluation for HT. A rater calculated CBV maps in PMA™ (ASIST-Japan) and performed image registration and region of interest analyses in MIPAV™ (NIH). The rater repeated the CBV analysis without image registration using DICOM software available on the scanner. Multinomial regression with covariates of baseline NIHSS, DWI lesion size, and CBV ratio was performed. All MRI scans were reviewed by expert readers blinded to the CBV analyses to determine the presence of HT using the ECASS-II criteria. Results: Seventy-six patients met the study criteria with a mean (SD) age of 68.1 (±14.1) years, median baseline NIHSS of 12 (IQR25-75: 5-18) and median onset to first MRI of 109 minutes (IQR25-75: 82-157). Thirty-six percent of patients (27/76) were positive for HT post-thrombolysis. The mean CBV ratio was 0.25 (STD ± 0.23) in the positive HT patients compared to 0.55 (STD ±0.24) in the negative HT patients. Multinomial regression demonstrated that the CBV ratio < 0.5 (p<0.006) and baseline NIHSS > 15 (p<0.034) significantly predicted the occurrence of any HT. The CBV ratio < 0.5 was the only independent predictor of severe HT, PH1 or PH2 (p<0.008). DWI lesion size using > 100 ml involvement of the MCA territory was not significant in predicting any or severe HT. Conclusions: Pre-treatment CBV ratio used in combination with baseline NIHSS are promising predictors of HT after standard IV-tPA. The ability to calculate CBV ratios directly on the scanner supports usage in acute intervention decision making.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
George Harston ◽  
James Kennedy

Introduction: The Acute Stroke Imaging Roadmap III identifies structural distortion due to vasogenic edema and hemorrhage as a research priority for defining final infarction. Non-linear registration (NLR) of a follow up scan to an undistorted presenting scan could correct for distortions due to edema, hemorrhage or atrophy, achieving this goal. In addition, the difference between the volume of infarction following NLR and the volume following a rigid body registration (RBR) reflects the degree of anatomical distortion. In this study we evaluate this technique to correct for subacute edema at different timepoints, and generate a metric to quantify brain swelling at these times. We determine whether early edema at 24 hours predicts edema at 1 week. Methods: Patients with non-lacunar ischemic stroke were recruited into a MRI study. Patients had structural T1-weighted, T2-weighted FLAIR and diffusion-weighted imaging (DWI, b=1000/0) at presentation, 24hrs, 1wk and 1mo. Infarction was defined manually at 24hrs using DWI, and at 1wk and 1mo using FLAIR image by 2 raters. To quantify edema, both NLR warps and RBR matrices were generated between the T1 images at each timepoint to the presenting T1 scan. Infarct masks were transformed to presenting image space using RBR and NLR, and the relative difference in volumes used to quantify the Edema Metric (EM). Results: 34 patients were recruited into the study. NLR corrected for distortions due to edema and hemorrhagic transformation at the 24hr and 1wk timepoints. The EM at 24 hours, 1 week and 1 month were 17.7% (p=0.009), 26.5% (p=0.02), and 7.1% (p=0.05) respectively for the manually defined infarct masks. EM at 24 hours predicted edema at 1 week (r 2 =37%, p=0.009), but not at 1 month (r 2 =3%, p=0.6). Conclusions: NLR provides an opportunity to correct for edema at subacute timepoints and by comparing infarct volumes to those following RBR provides a measure of edema. The EM quantifies the contribution of edema at 24hrs and 1wk, and potentially allows the selection of patients at 24hrs who are likely to develop significant swelling at 1 week. The EM may also be useful in stroke trials to quantify the effect sizes of treatments aimed at minimizing edema in stroke.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Shuhei Okazaki ◽  
Takeshi Yoshimoto ◽  
Hiroshi Yamagami ◽  
Katsufumi Kajimoto ◽  
Mikito Hayakawa ◽  
...  

Background and Purpose: Post-ischemic hyperperfusion has been considered as a risk factor of hemorrhagic transformation and poor prognosis. To date, however, there is a lack of data about the pathological significance of hyperperfusion after reperfusion therapy. In this study, we evaluated the relationship between hemorrhagic transformation and post-ischemic hyperperfusion after reperfusion therapy by using arterial spin labeled perfusion MRI (ASL) and 123 I IMP-SPECT. Methods: We retrospectively collected data of acute stroke patients with middle cerebral artery (MCA) occlusion who received intravenous thrombolysis and/or endovascular therapy, and underwent pulsed ASL using Q2TIPS-FAIR with 3D-TGSE readout and 123 I IMP-SPECT using dual-table ARG method within 14 days of stroke onset from November 2015 to June 2016. Ipsilateral-contralateral regional cerebral blood flow ratio (IC ratio) was calculated by using three-dimensional stereotactic ROI template (3DSRT) software. Results: Among 47 consecutive acute stroke patients with the MCA occlusion who received reperfusion therapy, 21 underwent only ASL and 10 underwent both ASL and SPECT after reperfusion therapy. The IC ratio of ASL was well correlated with that of SPECT in the MCA territory (r=0.65, p <0.001). Hemorrhagic transformation was observed in 7 patients. IC ratio was higher in patients with hemorrhagic transformation after reperfusion therapy than those without hemorrhagic transformation (2.19±0.35 vs 0.99±0.19, p=0.005). Focal post-ischemic hyperperfusion (IC ratio >1.5) was detected in 7 of 31 patients (23%). The presence of post-ischemic hyperperfusion was significantly associated with hemorrhagic transformation after reperfusion therapy (odds ratio 9.3, 95% confidence interval 1.4 to 64.0, p=0.03). Conclusions: Post-ischemic hyperperfusion detected by ASL predicts hemorrhagic transformation after reperfusion therapy. ASL hyperperfusion may indicate the disruption of blood brain barrier after reperfusion therapy.


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Fabien Scalzo ◽  
Songlin Yu ◽  
Sagar Patel ◽  
David Liebeskind ◽  
Danny Wang

Background: Hyperperfusion detected on arterial spin labeling (ASL) images acquired after stroke onset has been shown to correlate with subsequent hemorrhagic transformation (HT). Presence of hyperperfusion is typically detected by visual review of arterial spin labeling cerebral blood flow (CBF). Such a review is subjective as it is challenged by inter-reader variability, noise, and lack of standard threshold. We present in this study a quantitative hyperperfusion detection model that can provide an objective decision support for the interpretation of ASL CBF maps and rapidly delineate hyperperfusion regions. Methods: ASL Cerebral blood flow (CBF) maps of acute stroke patients presenting with an occlusion in the MCA territory were coregistered to a standardized atlas space. To achieve reliable detection of ASL hyperperfusion, we formalize the problem as a nonlinear classification that relates regional voxel intensity values to the corresponding binary label (normal or hyperperfused). Our method takes into account the healthy contralateral hemisphere and its CBF intensity values during the determination of hyperperfusion of a voxel. Each input feature vector combines the regional intensity values at the voxel of interest, its contralateral matched region, and the distribution of the difference between them. Each input vector is associated to a label corresponding to the presence of hyperperfusion that was manually established by consensus between experts. The predicted hyperperfusion regions were compared to a groundtruth that manually established by two researchers. Results: A total of 361 ASL scans were collected from 221 patients (age=72±17 years; 45% males). Hyperperfusion was detected in 76 patients that were subsequently used in our analysis. An AUC of 83±5% was reached after a leave-one-out cross-validation, which corresponds to the accuracy in detecting hyperperfusion compared to manual delineation of hyperperfusion on ASL CBF maps. Conclusion: Pattern recognition based on a nonlinear regression can provide an accurate and objective measure of hyperperfusion on ASL CBF images and could therefore improve the detection of hemorrhagic transformation in acute stroke patients.


Pflege ◽  
1999 ◽  
Vol 12 (1) ◽  
pp. 21-27
Author(s):  
Marit Kirkevold

Eine Übersicht der bestehenden Literatur weist auf Unsicherheiten bezüglich der spezifischen Rolle der Pflegenden in der Rehabilitation von Hirnschlagpatientinnen und -patienten hin. Es existieren zwei unterschiedliche Begrifflichkeiten für die Rolle der Pflegenden, keine davon bezieht sich auf spezifische Rehabilitationsziele oder Patientenergebnisse. Ein anfänglicher theoretischer Beitrag der Rolle der Pflege in der Genesung vom Hirnschlag wird als Struktur unterbreitet, um die therapeutischen Aspekte der Pflege im Koordinieren, Erhalten und Üben zu vereinen. Bestehende Literatur untermauert diesen Beitrag. Weitere Forschung ist jedoch notwendig, um den spezifischen Inhalt und Fokus der Pflege in der Genesung bei Hirnschlag zu entwickeln.


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