Pub Date : 2020-06-01DOI: 10.1177/0271678X19861448
Guang-Huar Young, Sung-Chun Tang, Vincent Wu, Kuo-Chuan Wang, Jing-Yi Nong, Po-Yuan Huang, Chaur-Jong Hu, H. Chiou, J. Jeng, C. Hsu
Our study aimed to establish the role of hemojuvelin (HJV) in acute ischemic stroke (AIS). We performed immunohistochemistry for HJV expression in human brain tissues from 10 AIS and 2 non-stroke autopsy subjects. Plasma HJV was measured in 112 AIS patients within 48 h after stroke. The results showed significantly increased HJV expression in brain tissues from AIS patients compare to non-stroke subjects. After adjusting for clinical variables, plasma levels of HJV within 48 h after stroke were an independent predictor of poor functional outcome three months post-stroke (OR:1.78, 95% CI: 1.03–3.07; P = 0.038). In basic part, Western blotting showed that HJV expression in mice brains was apparent at 3 h after middle cerebral artery occlusion (MCAO), and increased significantly at 72 h. In cultured cortical neurons, expression of HJV protein increased remarkably 24 h after oxygen glucose deprivation (OGD), and small interfering RNAs (siHJV) transfected OGD neurons had a lower apoptotic rate. Importantly, 72 h post-MCAO, HJV knockout mice had significantly smaller infarcts and less expression of cleaved caspase-3 protein compared with wild-type mice. In summary, HJV participates in the mechanisms of post-stroke neuronal injury, and that plasma HJV levels can be a potential early outcome indicator for AIS patients.
{"title":"The functional role of hemojuvelin in acute ischemic stroke","authors":"Guang-Huar Young, Sung-Chun Tang, Vincent Wu, Kuo-Chuan Wang, Jing-Yi Nong, Po-Yuan Huang, Chaur-Jong Hu, H. Chiou, J. Jeng, C. Hsu","doi":"10.1177/0271678X19861448","DOIUrl":"https://doi.org/10.1177/0271678X19861448","url":null,"abstract":"Our study aimed to establish the role of hemojuvelin (HJV) in acute ischemic stroke (AIS). We performed immunohistochemistry for HJV expression in human brain tissues from 10 AIS and 2 non-stroke autopsy subjects. Plasma HJV was measured in 112 AIS patients within 48 h after stroke. The results showed significantly increased HJV expression in brain tissues from AIS patients compare to non-stroke subjects. After adjusting for clinical variables, plasma levels of HJV within 48 h after stroke were an independent predictor of poor functional outcome three months post-stroke (OR:1.78, 95% CI: 1.03–3.07; P = 0.038). In basic part, Western blotting showed that HJV expression in mice brains was apparent at 3 h after middle cerebral artery occlusion (MCAO), and increased significantly at 72 h. In cultured cortical neurons, expression of HJV protein increased remarkably 24 h after oxygen glucose deprivation (OGD), and small interfering RNAs (siHJV) transfected OGD neurons had a lower apoptotic rate. Importantly, 72 h post-MCAO, HJV knockout mice had significantly smaller infarcts and less expression of cleaved caspase-3 protein compared with wild-type mice. In summary, HJV participates in the mechanisms of post-stroke neuronal injury, and that plasma HJV levels can be a potential early outcome indicator for AIS patients.","PeriodicalId":15356,"journal":{"name":"Journal of Cerebral Blood Flow & Metabolism","volume":"11 1","pages":"1316 - 1327"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91020685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-01Epub Date: 2019-11-20DOI: 10.1177/0271678X19888967
François De Guio, Marco Duering, Franz Fazekas, Frank-Erik De Leeuw, Steven M Greenberg, Leonardo Pantoni, Agnès Aghetti, Eric E Smith, Joanna Wardlaw, Eric Jouvent
{"title":"Brain atrophy in cerebral small vessel diseases: Extent, consequences, technical limitations and perspectives: The HARNESS initiative.","authors":"François De Guio, Marco Duering, Franz Fazekas, Frank-Erik De Leeuw, Steven M Greenberg, Leonardo Pantoni, Agnès Aghetti, Eric E Smith, Joanna Wardlaw, Eric Jouvent","doi":"10.1177/0271678X19888967","DOIUrl":"10.1177/0271678X19888967","url":null,"abstract":"","PeriodicalId":15356,"journal":{"name":"Journal of Cerebral Blood Flow & Metabolism","volume":"72 4 1","pages":"231-245"},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7370623/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72877061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-02DOI: 10.1177/0271678X19892660
A. Pandey, B. Daou, N. Chaudhary, G. Xi
Intracerebral hemorrhage is associated with significant morbidity and mortality. Some clinical trials demonstrated a trend towards benefit with surgical evacuation of intracerebral hemorrhage, without strong statistically significant results. Subsequent studies focused on minimally invasive techniques. Improved outcomes were more likely with surgical reduction of intracerebral hemorrhage volume to ≤15 mL. Deferoxamine is currently being evaluated as a therapeutic tool in intracerebral hemorrhage with promising results. There continues to be a lack of level I evidence supporting medical and surgical tools for intracerebral hemorrhage evacuation. Could a combination of minimally invasive surgery with hematoma lysis and Deferoxamine result in more effective hematoma evacuation?
{"title":"A combination of Deferoxamine mesylate and minimally invasive surgery with hematoma lysis for evacuation of intracerebral hemorrhage","authors":"A. Pandey, B. Daou, N. Chaudhary, G. Xi","doi":"10.1177/0271678X19892660","DOIUrl":"https://doi.org/10.1177/0271678X19892660","url":null,"abstract":"Intracerebral hemorrhage is associated with significant morbidity and mortality. Some clinical trials demonstrated a trend towards benefit with surgical evacuation of intracerebral hemorrhage, without strong statistically significant results. Subsequent studies focused on minimally invasive techniques. Improved outcomes were more likely with surgical reduction of intracerebral hemorrhage volume to ≤15 mL. Deferoxamine is currently being evaluated as a therapeutic tool in intracerebral hemorrhage with promising results. There continues to be a lack of level I evidence supporting medical and surgical tools for intracerebral hemorrhage evacuation. Could a combination of minimally invasive surgery with hematoma lysis and Deferoxamine result in more effective hematoma evacuation?","PeriodicalId":15356,"journal":{"name":"Journal of Cerebral Blood Flow & Metabolism","volume":"24 1","pages":"456 - 458"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81994205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-27DOI: 10.1177/0271678X19891359
Alexander Ruesch, Samantha E. Schmitt, Jason Yang, Matthew A. Smith, J. Kainerstorfer
Intracranial pressure (ICP) is typically measured invasively through a sensor placed inside the brain or a needle inserted into the spinal canal, limiting the patient population on which this assessment can be performed. Currently, non-invasive methods are limited due to lack of sensitivity and thus only apply to extreme cases of increased ICP, instead of use in general clinical practice. We demonstrate a novel application for near-infrared spectroscopy (NIRS) to accurately estimate ICP changes over time. Using a non-human primate (Rhesus Macaque) model, we collected optical data while we induced ICP oscillations at multiple ICP levels obtained by manipulating the height of a fluid column connected via a catheter to the lateral ventricle. Hemodynamic responses to ICP changes were measured at the occipital pole and compared to changes detected by a conventional intraparenchymal ICP probe. We demonstrate that hemoglobin concentrations are highly correlated with induced ICP oscillations and that this response is frequency dependent. We translated the NIRS data into non-invasive ICP measurements via a fitted non-parametric transfer function, demonstrating a match in both magnitude and time alignment with an invasively measured reference. Our results demonstrate that NIRS has the potential for non-invasive ICP monitoring.
{"title":"Fluctuations in intracranial pressure can be estimated non-invasively using near-infrared spectroscopy in non-human primates","authors":"Alexander Ruesch, Samantha E. Schmitt, Jason Yang, Matthew A. Smith, J. Kainerstorfer","doi":"10.1177/0271678X19891359","DOIUrl":"https://doi.org/10.1177/0271678X19891359","url":null,"abstract":"Intracranial pressure (ICP) is typically measured invasively through a sensor placed inside the brain or a needle inserted into the spinal canal, limiting the patient population on which this assessment can be performed. Currently, non-invasive methods are limited due to lack of sensitivity and thus only apply to extreme cases of increased ICP, instead of use in general clinical practice. We demonstrate a novel application for near-infrared spectroscopy (NIRS) to accurately estimate ICP changes over time. Using a non-human primate (Rhesus Macaque) model, we collected optical data while we induced ICP oscillations at multiple ICP levels obtained by manipulating the height of a fluid column connected via a catheter to the lateral ventricle. Hemodynamic responses to ICP changes were measured at the occipital pole and compared to changes detected by a conventional intraparenchymal ICP probe. We demonstrate that hemoglobin concentrations are highly correlated with induced ICP oscillations and that this response is frequency dependent. We translated the NIRS data into non-invasive ICP measurements via a fitted non-parametric transfer function, demonstrating a match in both magnitude and time alignment with an invasively measured reference. Our results demonstrate that NIRS has the potential for non-invasive ICP monitoring.","PeriodicalId":15356,"journal":{"name":"Journal of Cerebral Blood Flow & Metabolism","volume":"9 1","pages":"2304 - 2314"},"PeriodicalIF":0.0,"publicationDate":"2019-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88400520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-25DOI: 10.1177/0271678X19890931
Qiang Zhao, T. Yan, M. Chopp, P. Venkat, Jieli Chen
Stroke is a leading cause of mortality and morbidity, with long-term debilitating effects. Accumulating evidence from experimental studies as well as observational studies in patients suggests a cross talk between the brain and kidney after stroke. Stroke may lead to kidney dysfunction which can adversely impact patient outcome. In this review article, we discuss the epidemiology and mechanisms of brain–kidney interaction following ischemic stroke. Specifically, we discuss the role of the central autonomic network, autoregulation, inflammatory and immune responses, the role of extracellular vesicles and their cargo microRNA, in mediating brain–kidney interaction following stroke. Understanding the bidirectional nature of interaction between the brain and kidney after cerebral injury would have clinical implications for the treatment of stroke and overall patient outcome.
{"title":"Brain–kidney interaction: Renal dysfunction following ischemic stroke","authors":"Qiang Zhao, T. Yan, M. Chopp, P. Venkat, Jieli Chen","doi":"10.1177/0271678X19890931","DOIUrl":"https://doi.org/10.1177/0271678X19890931","url":null,"abstract":"Stroke is a leading cause of mortality and morbidity, with long-term debilitating effects. Accumulating evidence from experimental studies as well as observational studies in patients suggests a cross talk between the brain and kidney after stroke. Stroke may lead to kidney dysfunction which can adversely impact patient outcome. In this review article, we discuss the epidemiology and mechanisms of brain–kidney interaction following ischemic stroke. Specifically, we discuss the role of the central autonomic network, autoregulation, inflammatory and immune responses, the role of extracellular vesicles and their cargo microRNA, in mediating brain–kidney interaction following stroke. Understanding the bidirectional nature of interaction between the brain and kidney after cerebral injury would have clinical implications for the treatment of stroke and overall patient outcome.","PeriodicalId":15356,"journal":{"name":"Journal of Cerebral Blood Flow & Metabolism","volume":"45 1","pages":"246 - 262"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74170077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-21DOI: 10.1177/0271678X19889089
Brittany A. Matenchuk, M. James, Rachel J. Skow, Paige K Wakefield, Christina M. MacKay, C. Steinback, Margie H. Davenport
Cerebrovascular adaptation to pregnancy is poorly understood. We sought to assess cerebrovascular regulation in response to visual stimulation, hypercapnia and exercise across the three trimesters of pregnancy. Using transcranial Doppler (TCD) ultrasound, middle and posterior cerebral artery mean blood velocities (MCAvmean and PCAvmean) were measured continuously at rest and in response to (1) visual stimulation to assess neurovascular coupling (NVC); (2) a modified Duffin hyperoxic CO2 rebreathe test, and (3) an incremental cycling exercise test to volitional fatigue in non-pregnant (n = 26; NP) and pregnant women (first trimester [n = 13; TM1], second trimester [n = 21; TM2], and third trimester [n = 20; TM3]) in total 47 women. At rest, MCAvmean and PETCO2 were lower in TM2 compared to NP. PCAvmean was lower in TM2 but not TM1 or TM3 compared to NP. Cerebrovascular reactivity in MCAvmean and PCAvmean during the hypercapnic rebreathing test was not different between pregnant and non-pregnant women. MCAvmean continued to increase over the second half of the exercise test in TM2 and TM3, while it decreased in NP due to differences in ΔPETCO2 between groups. Pregnant women experienced a delayed decrease in MCAvmean in response to maximal exercise compared to non-pregnant controls which was explained by CO2 reactivity and PETCO2 level.
{"title":"Longitudinal study of cerebral blood flow regulation during exercise in pregnancy","authors":"Brittany A. Matenchuk, M. James, Rachel J. Skow, Paige K Wakefield, Christina M. MacKay, C. Steinback, Margie H. Davenport","doi":"10.1177/0271678X19889089","DOIUrl":"https://doi.org/10.1177/0271678X19889089","url":null,"abstract":"Cerebrovascular adaptation to pregnancy is poorly understood. We sought to assess cerebrovascular regulation in response to visual stimulation, hypercapnia and exercise across the three trimesters of pregnancy. Using transcranial Doppler (TCD) ultrasound, middle and posterior cerebral artery mean blood velocities (MCAvmean and PCAvmean) were measured continuously at rest and in response to (1) visual stimulation to assess neurovascular coupling (NVC); (2) a modified Duffin hyperoxic CO2 rebreathe test, and (3) an incremental cycling exercise test to volitional fatigue in non-pregnant (n = 26; NP) and pregnant women (first trimester [n = 13; TM1], second trimester [n = 21; TM2], and third trimester [n = 20; TM3]) in total 47 women. At rest, MCAvmean and PETCO2 were lower in TM2 compared to NP. PCAvmean was lower in TM2 but not TM1 or TM3 compared to NP. Cerebrovascular reactivity in MCAvmean and PCAvmean during the hypercapnic rebreathing test was not different between pregnant and non-pregnant women. MCAvmean continued to increase over the second half of the exercise test in TM2 and TM3, while it decreased in NP due to differences in ΔPETCO2 between groups. Pregnant women experienced a delayed decrease in MCAvmean in response to maximal exercise compared to non-pregnant controls which was explained by CO2 reactivity and PETCO2 level.","PeriodicalId":15356,"journal":{"name":"Journal of Cerebral Blood Flow & Metabolism","volume":"61 1","pages":"2278 - 2288"},"PeriodicalIF":0.0,"publicationDate":"2019-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81404403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-13DOI: 10.1177/0271678X19888123
Jia Guo, E. Gong, A. Fan, M. Goubran, M. Khalighi, G. Zaharchuk
To improve the quality of MRI-based cerebral blood flow (CBF) measurements, a deep convolutional neural network (dCNN) was trained to combine single- and multi-delay arterial spin labeling (ASL) and structural images to predict gold-standard 15O-water PET CBF images obtained on a simultaneous PET/MRI scanner. The dCNN was trained and tested on 64 scans in 16 healthy controls (HC) and 16 cerebrovascular disease patients (PT) with 4-fold cross-validation. Fidelity to the PET CBF images and the effects of bias due to training on different cohorts were examined. The dCNN significantly improved CBF image quality compared with ASL alone (mean ± standard deviation): structural similarity index (0.854 ± 0.036 vs. 0.743 ± 0.045 [single-delay] and 0.732 ± 0.041 [multi-delay], P < 0.0001); normalized root mean squared error (0.209 ± 0.039 vs. 0.326 ± 0.050 [single-delay] and 0.344 ± 0.055 [multi-delay], P < 0.0001). The dCNN also yielded mean CBF with reduced estimation error in both HC and PT (P < 0.001), and demonstrated better correlation with PET. The dCNN trained with the mixed HC and PT cohort performed the best. The results also suggested that models should be trained on cases representative of the target population.
为了提高基于MRI的脑血流量(CBF)测量的质量，我们训练了一个深度卷积神经网络(dCNN)，将单延迟和多延迟动脉自旋标记(ASL)和结构图像结合起来，预测同时在PET/MRI扫描仪上获得的金标准15O-water PET CBF图像。dCNN在16名健康对照(HC)和16名脑血管病患者(PT)中进行了64次扫描训练和测试，并进行了4倍交叉验证。对PET脑血流图像的保真度和训练对不同队列的偏差影响进行了检查。与单独使用ASL相比，dCNN显著改善了CBF图像质量(平均值±标准差):结构相似性指数(0.854±0.036 vs. 0.743±0.045[单延迟]和0.732±0.041[多延迟]，P < 0.0001);归一化均方根误差(0.209±0.039 vs. 0.326±0.050[单延迟]和0.344±0.055[多延迟]，P < 0.0001)。dCNN在HC和PT的平均CBF估计误差均降低(P < 0.001)，并且与PET的相关性更好。采用HC和PT混合队列训练的dCNN表现最好。研究结果还表明，应该根据代表目标人群的案例对模型进行训练。
{"title":"Predicting 15O-Water PET cerebral blood flow maps from multi-contrast MRI using a deep convolutional neural network with evaluation of training cohort bias","authors":"Jia Guo, E. Gong, A. Fan, M. Goubran, M. Khalighi, G. Zaharchuk","doi":"10.1177/0271678X19888123","DOIUrl":"https://doi.org/10.1177/0271678X19888123","url":null,"abstract":"To improve the quality of MRI-based cerebral blood flow (CBF) measurements, a deep convolutional neural network (dCNN) was trained to combine single- and multi-delay arterial spin labeling (ASL) and structural images to predict gold-standard 15O-water PET CBF images obtained on a simultaneous PET/MRI scanner. The dCNN was trained and tested on 64 scans in 16 healthy controls (HC) and 16 cerebrovascular disease patients (PT) with 4-fold cross-validation. Fidelity to the PET CBF images and the effects of bias due to training on different cohorts were examined. The dCNN significantly improved CBF image quality compared with ASL alone (mean ± standard deviation): structural similarity index (0.854 ± 0.036 vs. 0.743 ± 0.045 [single-delay] and 0.732 ± 0.041 [multi-delay], P < 0.0001); normalized root mean squared error (0.209 ± 0.039 vs. 0.326 ± 0.050 [single-delay] and 0.344 ± 0.055 [multi-delay], P < 0.0001). The dCNN also yielded mean CBF with reduced estimation error in both HC and PT (P < 0.001), and demonstrated better correlation with PET. The dCNN trained with the mixed HC and PT cohort performed the best. The results also suggested that models should be trained on cases representative of the target population.","PeriodicalId":15356,"journal":{"name":"Journal of Cerebral Blood Flow & Metabolism","volume":"48 1","pages":"2240 - 2253"},"PeriodicalIF":0.0,"publicationDate":"2019-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85765212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-13DOI: 10.1177/0271678X19886667
Tomas Vikner, L. Nyberg, Madelene Holmgren, J. Malm, A. Eklund, A. Wåhlin
Recent reports have suggested that age-related arterial stiffening and excessive cerebral arterial pulsatility cause blood–brain barrier breakdown, brain atrophy and cognitive decline. This has spurred interest in developing non-invasive methods to measure pulsatility in distal vessels, closer to the cerebral microcirculation. Here, we report a method based on four-dimensional (4D) flow MRI to estimate a global composite flow waveform of distal cerebral arteries. The method is based on finding and sampling arterial waveforms from thousands of cross sections in numerous small vessels of the brain, originating from cerebral cortical arteries. We demonstrate agreement with internal and external reference methods and show the ability to capture significant increases in distal cerebral arterial pulsatility as a function of age. The proposed approach can be used to advance our understanding regarding excessive arterial pulsatility as a potential trigger of cognitive decline and dementia.
{"title":"Characterizing pulsatility in distal cerebral arteries using 4D flow MRI","authors":"Tomas Vikner, L. Nyberg, Madelene Holmgren, J. Malm, A. Eklund, A. Wåhlin","doi":"10.1177/0271678X19886667","DOIUrl":"https://doi.org/10.1177/0271678X19886667","url":null,"abstract":"Recent reports have suggested that age-related arterial stiffening and excessive cerebral arterial pulsatility cause blood–brain barrier breakdown, brain atrophy and cognitive decline. This has spurred interest in developing non-invasive methods to measure pulsatility in distal vessels, closer to the cerebral microcirculation. Here, we report a method based on four-dimensional (4D) flow MRI to estimate a global composite flow waveform of distal cerebral arteries. The method is based on finding and sampling arterial waveforms from thousands of cross sections in numerous small vessels of the brain, originating from cerebral cortical arteries. We demonstrate agreement with internal and external reference methods and show the ability to capture significant increases in distal cerebral arterial pulsatility as a function of age. The proposed approach can be used to advance our understanding regarding excessive arterial pulsatility as a potential trigger of cognitive decline and dementia.","PeriodicalId":15356,"journal":{"name":"Journal of Cerebral Blood Flow & Metabolism","volume":"157 1","pages":"2429 - 2440"},"PeriodicalIF":0.0,"publicationDate":"2019-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77646683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-11DOI: 10.1177/0271678X19887358
Caroline Bendell, S. Moosavi, M. Herigstad
Blood oxygen level dependent (BOLD) fMRI is a common technique for measuring brain activation that could be affected by low-level carbon monoxide (CO) exposure from, e.g. smoking. This study aimed to probe the vulnerability of BOLD fMRI to CO and determine whether it may constitute a significant neuroimaging confound. Low-level (6 ppm exhaled) CO effects on BOLD response were assessed in 12 healthy never-smokers on two separate experimental days (CO and air control). fMRI tasks were breath-holds (hypercapnia), visual stimulation and fingertapping. BOLD fMRI response was lower during breath holds, visual stimulation and fingertapping in the CO protocol compared to the air control protocol. Behavioural and physiological measures remained unchanged. We conclude that BOLD fMRI might be vulnerable to changes in baseline CO, and suggest exercising caution when imaging populations exposed to elevated CO levels. Further work is required to fully elucidate the impact on CO on fMRI and its underlying mechanisms.
{"title":"Low-level carbon monoxide exposure affects BOLD fMRI response","authors":"Caroline Bendell, S. Moosavi, M. Herigstad","doi":"10.1177/0271678X19887358","DOIUrl":"https://doi.org/10.1177/0271678X19887358","url":null,"abstract":"Blood oxygen level dependent (BOLD) fMRI is a common technique for measuring brain activation that could be affected by low-level carbon monoxide (CO) exposure from, e.g. smoking. This study aimed to probe the vulnerability of BOLD fMRI to CO and determine whether it may constitute a significant neuroimaging confound. Low-level (6 ppm exhaled) CO effects on BOLD response were assessed in 12 healthy never-smokers on two separate experimental days (CO and air control). fMRI tasks were breath-holds (hypercapnia), visual stimulation and fingertapping. BOLD fMRI response was lower during breath holds, visual stimulation and fingertapping in the CO protocol compared to the air control protocol. Behavioural and physiological measures remained unchanged. We conclude that BOLD fMRI might be vulnerable to changes in baseline CO, and suggest exercising caution when imaging populations exposed to elevated CO levels. Further work is required to fully elucidate the impact on CO on fMRI and its underlying mechanisms.","PeriodicalId":15356,"journal":{"name":"Journal of Cerebral Blood Flow & Metabolism","volume":"15 1","pages":"2215 - 2224"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89777204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-11DOI: 10.1177/0271678X19887781
C. Salinas, Talakad G. Lohith, Ajay Purohit, A. Struyk, C. Sur, I. Bennacef, J. Beaver, L. Martarello
[18F]MK-6240 is a selective, high-affinity PET radiotracer for imaging neurofibrillary tangles (NFT) in Alzheimer’s disease (AD). Herein, we report test–retest (T–RT) reproducibility of [18F]MK-6240 in AD and healthy volunteers (HV). Twelve subjects with AD and three cognitively normal HV were enrolled in the study and dynamically scanned for 150 min with [18F]MK-6240 under a T–RT protocol. Two radioactivity doses were investigated: 165 ± 3 MBq (n = 6) and 300 ± 40 MBq (n = 9). Serial arterial blood samples were taken for each scan to obtain metabolite-corrected input functions. Following intravenous administration of [18F]MK-6240, the tracer rapidly partitioned into the brain and its heterogenous distribution pattern was consistent with known NFT pathology in AD. In contrast, uptake in HV was low and uniform across the brain parenchyma. Across all subjects, average T–RT variabilities in NFT-rich regions were ∼21%, ∼14% and ∼6% for various quantitative metrics: total distribution volume (VT), binding potential (BPND), and standardized uptake ratio (SUVR90–120), respectively. No significant differences in SUVR T–RT variability were observed between the high and low injected radioactivity groups (5.6% and 6.1%, respectively). This work suggests [18F]MK-6240 has adequate SUVR T–RT characteristics supporting the use of this outcome in future studies.
{"title":"Test–retest characteristic of [18F]MK-6240 quantitative outcomes in cognitively normal adults and subjects with Alzheimer’s disease","authors":"C. Salinas, Talakad G. Lohith, Ajay Purohit, A. Struyk, C. Sur, I. Bennacef, J. Beaver, L. Martarello","doi":"10.1177/0271678X19887781","DOIUrl":"https://doi.org/10.1177/0271678X19887781","url":null,"abstract":"[18F]MK-6240 is a selective, high-affinity PET radiotracer for imaging neurofibrillary tangles (NFT) in Alzheimer’s disease (AD). Herein, we report test–retest (T–RT) reproducibility of [18F]MK-6240 in AD and healthy volunteers (HV). Twelve subjects with AD and three cognitively normal HV were enrolled in the study and dynamically scanned for 150 min with [18F]MK-6240 under a T–RT protocol. Two radioactivity doses were investigated: 165 ± 3 MBq (n = 6) and 300 ± 40 MBq (n = 9). Serial arterial blood samples were taken for each scan to obtain metabolite-corrected input functions. Following intravenous administration of [18F]MK-6240, the tracer rapidly partitioned into the brain and its heterogenous distribution pattern was consistent with known NFT pathology in AD. In contrast, uptake in HV was low and uniform across the brain parenchyma. Across all subjects, average T–RT variabilities in NFT-rich regions were ∼21%, ∼14% and ∼6% for various quantitative metrics: total distribution volume (VT), binding potential (BPND), and standardized uptake ratio (SUVR90–120), respectively. No significant differences in SUVR T–RT variability were observed between the high and low injected radioactivity groups (5.6% and 6.1%, respectively). This work suggests [18F]MK-6240 has adequate SUVR T–RT characteristics supporting the use of this outcome in future studies.","PeriodicalId":15356,"journal":{"name":"Journal of Cerebral Blood Flow & Metabolism","volume":"56 1","pages":"2179 - 2187"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88802000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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