Article
Radiology, Nuclear Medicine & Medical Imaging
Jeffrey M. Dendy, Sean G. Hughes, Jonathan H. Soslow, Daniel E. Clark, Cynthia B. Paschal, John C. Gore
Summary: We propose a method for quantitatively measuring drug-induced microvascular volume changes and blood oxygenation using calibrated blood oxygen level-dependent MRI. Through the examination of healthy rats, we demonstrate the potential of this method to examine microvascular disease in different disease states without the use of radiopharmaceuticals or gadolinium-based contrast agents.
INVESTIGATIVE RADIOLOGY
(2022)
Article
Neurosciences
Sebastian Dresbach, Laurentius (Renzo) Huber, Omer Faruk Gulban, Rainer Goebel
Summary: Layers and columns are the dominant processing units in the human cortex, and the blood oxygenation dependent (BOLD) signal is biased towards unwanted signals from large veins. This study shows that the vascular space occupancy (VASO) contrast can enhance the interpretability of layer-fMRI results by capturing complementary information of locally specific changes in cerebral blood volume (CBV) without the unwanted sensitivity amplifications of large veins. The study also develops a VASO acquisition procedure with short acquisition time and high spatial resolution, demonstrating the ability to capture layer-specific hemodynamic responses with high spatio-temporal resolution.
Article
Endocrinology & Metabolism
Alberto Arboit, Karla Krautwald, Frank Angenstein
Summary: Repeated high-frequency pulse-burst stimulations of the rat perforant pathway elicited positive BOLD responses in the right hippocampus, septum, and prefrontal cortex. However, when hippocampal neuronal afterdischarges were triggered, a delayed negative BOLD response in the prefrontal cortex was generated. The process was modulated by mACh receptors and affected the strength of the negative BOLD response.
JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM
(2022)
Article
Pediatrics
Toshiyuki Imanishi, Wakako Sumiya, Chika Kanno, Masayuki Kanno, Ken Kawabata, Masaki Shimizu
Summary: This study found that unstable cerebral blood flow may contribute to the occurrence of intraventricular haemorrhage in extremely low-birth-weight infants. Cerebral blood volume was significantly correlated with internal cerebral vein velocity, but not anterior cerebral artery velocity. Autoregulation function was not impaired. These findings may aid future research on predicting intraventricular haemorrhage.
EUROPEAN JOURNAL OF PEDIATRICS
(2023)
Article
Clinical Neurology
Tobias Djamsched Faizy, Michael Mlynash, Reza Kabiri, Soren Christensen, Gabriella Kuraitis, Lukas Meyer, Matthias Bechstein, Noel Van Horn, Maarten G. Lansberg, Greg Albers, Jens Fiehler, Max Wintermark, Jeremy J. Heit
Summary: This study found that favorable pial arterial collaterals (PAC) and venous outflow (VO) were associated with early neurological improvement (ENI) after thrombectomy in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). Additionally, favorable tissue-level collaterals (TLC) predicted longer term functional recovery after thrombectomy, but the impact of TLC on ENI strongly depended on vessel reperfusion.
JOURNAL OF NEUROLOGY NEUROSURGERY AND PSYCHIATRY
(2022)
Article
Neurosciences
Icaro A. F. Oliveira, Wietske van der Zwaag, Luisa Raimondo, Serge O. Dumoulin, Jeroen C. W. Siero
Summary: Functional magnetic resonance imaging (fMRI) based on Blood Oxygenation Level Dependent (BOLD) contrast establishes a non-invasive localization of neuronal activity by studying the relationship between neuronal activation and hemodynamics. Research indicates a non-linear relationship between BOLD responses and VASO-CBV signal changes, potentially influenced by factors such as neuronal processes and large vessel contributions, suggesting similarities in overall interactions between CBV and BOLD responses.
Article
Neurosciences
Atena Akbari, Saskia Bollmann, Tonima S. Ali, Markus Barth
Summary: Functional magnetic resonance imaging (fMRI) using blood-oxygenation-level-dependent (BOLD) contrast is a widely used noninvasive method for studying human brain function. However, spatial signal specificity in depth-dependent fMRI can be degraded due to signal leakage. VAscular-Space-Occupancy (VASO) contrast, which measures cerebral blood volume, has shown higher spatial specificity compared to BOLD. In this study, a cortical vascular model was used to predict layer-specific BOLD and VASO responses in the human primary visual cortex, and the model's predictions were compared with experimental results. The results confirmed that VASO is less affected by large vessel effects compared to BOLD.
HUMAN BRAIN MAPPING
(2023)
Article
Physiology
A. Valerianova, M. Mlcek, O. Kittnar, T. Grus, L. Tejkl, V. Lejsek, J. Malik
Summary: This study investigated the impact of large arteriovenous fistulas on organ perfusion during partial and full Veno-arterial ECMO support. The results showed that opening a large arteriovenous fistula resulted in a decrease in effective systemic blood flow, particularly affecting carotid artery flow and cerebral tissue oxygenation.
FRONTIERS IN PHYSIOLOGY
(2023)
Article
Physiology
Christopher Lopez, Tanja Taivassalo, Maria G. Berru, Andres Saavedra, Hannah C. Rasmussen, Abhinandan Batra, Harneet Arora, Alex M. Roetzheim, Glenn A. Walter, Krista Vandenborne, Sean C. Forbes
Summary: The study found that the postcontractile blood oxygen level-dependent (BOLD) response is impaired in boys with Duchenne muscular dystrophy (DMD) after brief muscle contractions, and this impairment is correlated to disease severity. This measure may be valuable for evaluating treatments targeting microvascular function in DMD.
JOURNAL OF APPLIED PHYSIOLOGY
(2021)
Article
Pediatrics
Daniel Pfurtscheller, Christina H. Wolfsberger, Nina Hoeller, Bernhard Schwaberger, Lukas Mileder, Nariae Baik-Schneditz, Berndt Urlesberger, Gerhard Pichler
Summary: This study assessed the association between blood pressure, cerebral-regional-oxygen-saturation (crSO2), and cerebral-fractional-tissue-oxygen-extraction (cFTOE) in preterm neonates during immediate transition after birth, with and without respiratory support. The results showed a positive correlation between crSO2 and blood pressure, as well as a negative correlation between cFTOE and blood pressure in compromised neonates with respiratory support. These findings suggest an impaired cerebral autoregulation in preterm neonates with respiratory support.
FRONTIERS IN PEDIATRICS
(2022)
Article
Neurosciences
Kamil Uludag
Summary: In this primer, the author provides an overview of the physiological processes that contribute to the observed BOLD signal and introduces the physiologically-informed dynamic causal modeling (P-DCM) framework. The author discusses the physiological origin of different components of the BOLD signal and emphasizes the importance of correct physiological assumptions in making accurate inferences about neuronal activity and connectivity between brain regions. Additionally, the author presents the laminar BOLD signal model, which allows for the determination of laminar neuronal activity using high-resolution fMRI data.
Article
Radiology, Nuclear Medicine & Medical Imaging
Wenbo Li, Dapeng Liu, Peter C. M. van Zijl, Qin Qin
Summary: The study developed 3D MR1 methods for CBV and vCBV estimation with whole-brain coverage using FT-VS pulse trains, demonstrating high correlation between CBV and vCBV values in gray and white matter, and comparable results to existing literature.
MAGNETIC RESONANCE IN MEDICINE
(2021)
Article
Radiology, Nuclear Medicine & Medical Imaging
Wenbo Li, Dapeng Liu, Peter C. M. van Zijl, Qin Qin
Summary: In this study, 3D MR1 methods were developed for cerebral blood volume (CBV) and venous cerebral blood volume (vCBV) estimation with whole-brain coverage using Fourier transform based velocity-selective (FT-VS) pulse trains. Results showed high correlation of CBV and vCBV values in gray and white matter in different brain regions among healthy volunteers. The feasibility of FT-VS-based CBV and vCBV estimation for 3D acquisition with large spatial coverage was demonstrated.
MAGNETIC RESONANCE IN MEDICINE
(2021)
Article
Neurosciences
Sukhdeep Singh Bal, Fan Pei Gloria Yang, Yueh-Feng Sung, Ke Chen, Jiu-Haw Yin, Giia-Sheun Peng
Summary: This study demonstrates that rescaling the AIF leads to more accurate estimation of perfusion parameters, resulting in increased accuracy of CBF and Tmax values in MRI imaging of stroke patients.
Article
Oncology
Jerrold L. Boxerman, Bradley S. Snyder, Daniel P. Barboriak, Kathleen M. Schmainda
Summary: This study aimed to determine whether early change in cerebral blood volume from baseline (Delta CBV) could further stratify the T1 non-progressors according to overall (OS) and progression-free (PFS) survival. The results showed that increasing CBV at 2 weeks was associated with worse PFS and OS, while T1 response status (stable vs. decreasing enhancement) was not. Delta CBV at 2 weeks was also a good prognostic marker for OS-1 and PFS-6. Combining T1 progression and Delta CBV may yield a response assessment paradigm with 3-tiered OS stratification.
FRONTIERS IN ONCOLOGY
(2023)
Article
Neurosciences
Jose Sanchez-Bornot, Roberto C. Sotero, J. A. Scott Kelso, Ozguer Simsek, Damien Coyle
Summary: This study proposes a multi-penalized state-space model for analyzing unobserved dynamics, using a data-driven regularization method. Novel algorithms are developed to solve the model, and a cross-validation method is introduced to evaluate regularization parameters. The effectiveness of this method is validated through simulations and real data analysis, enabling a more accurate exploration of cognitive brain functions.