View Presentation Video

Baarbod Ashenagar ^1,2, Daniel Gomez^1,2,3, and Laura Lewis^1,2
1Department of Biomedical Engineering, Boston University, Boston, MA, United States, ²Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, ³Department of Radiology, Harvard Medical School, Boston, MA, United States

Keywords: Signal Modeling, Velocity & Flow, time-of-flight, flow-enhanced fMRI signal

Fast fMRI has recently been shown to be an effective method for detecting dynamic changes in cerebrospinal fluid flow, enabling measurement of a critical process for maintenance of brain health. However, while the inflow signal measured using fast fMRI is a surrogate for the underlying flow dynamics, it does not directly reflect the velocity and dynamics of flow. To understand the mapping between flow and the flow-enhanced MR signals they generate, we developed and validated a mathematical forward model that uses velocity as input and simulates dynamic fMRI inflow signal intensities for each slice of the imaging volume.

View Presentation Video

Maria Guidi¹, Fabio Mangini^1,2, Marta Moraschi^1,3, Daniele Mascali^1,3, Michela Fratini^3,4, Silvia Mangia⁵, Fabrizio Frezza², and Federico Giove^1,3
1MARBILab, Enrico Fermi Research Center, Rome, Italy, ²Sapienza University, Rome, Italy, ³Fondazione Santa Lucia IRCCS, Rome, Italy, ⁴CNR-NANOTEC, Rome, Italy, ⁵CMRR, Minneapolis, MN, United States

Keywords: Signal Modeling, fMRI, HRF

We characterized a deconvolved haemodynamic response function (dHRF) across the whole cortex exploiting a sine series expansion in a cohort of young healthy subjects from the Human Connectome Project. We report, for different tasks and brain regions, the amplitude, latency, time-to-peak and full-width at half maximum of the fitted BOLD response and of the dHRF. We show that each of those parameters vary throughout the cortex and, to a smaller extent, across subjects. Additionally, the use of a flexible model, like the one we explored in this study, reveals that the HRF in some brain regions deviates from canonicity.

View Presentation Video

Adam Richter¹, Jackson E. Moore¹, Maria Aristova¹, Ann Ragin¹, Susanne Schnell², Emily Rogalski³, Michael Markl¹, and Kelly Jarvis^1
1Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, ²Department of Medical Physics, Institute of Physics, University of Greifswald, Greifswald, Germany, ³Psychiatry and Behavioral Sciences, Northwestern University, Chicago, IL, United States

Keywords: Data Analysis, Velocity & Flow, Cerebral arteries

Age-related changes in cardiovascular hemodynamics may be associated with brain changes. However, this relationship is not clear since blood flow in the heart and brain are usually imaged and analyzed in separate exams and pipelines. We have developed a technique for parameter mapping in both the aorta and intracranial vessels to allow for integrated MRI evaluation of heart-brain hemodynamic coupling. This study demonstrates a single MRI study and analysis pipeline to facilitate more comprehensive, integrated heart-brain hemodynamic analysis in clinical and research settings.

View Presentation Video

Keywords: Data Acquisition, fMRI

This work evaluates capillary-weighted VS-ASL for subsecond functional cerebral blood flow (CBF) mapping with high microvascular specificity. Three experiments were conducted: one to demonstrate that capillary-weighted VS-ASL is mostly free from macrovascular contamination when compared to arterial-weighted VS-ASL, one to demonstrate that functional MRI is feasible with capillary-weighted VS-ASL at moderate repetition times, and one to show that, despite lower sensitivity, capillary-weighted functional MRI can be performed at subsecond temporal resolution. Our findings suggest that capillary-weighted VS-ASL may enable the study of fast functional CBF responses with high neuronal specificity.
 

View Presentation Video

Feng Xu^1,2, Dapeng Liu^1,2, Dan Zhu^1,2, Argye E. Hillis³, Arnold Bakker⁴, Anja Soldan³, Marilyn Albert³, Doris D. M. Lin¹, and Qin Qin^1,2
1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, ²F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, ³Department of Neurology, Johns Hopkins University, Baltimore, MD, United States, ⁴Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD, United States

Keywords: Data Acquisition, Arterial spin labelling

         Velocity selective inversion (VSI) based velocity selective arterial spin labeling (VSASL) was recommended by a recent guideline paper. We conducted a test-retest study to evaluate the reliability of 3D VSI-VSASL. The correlations between repeated measures were 0.94/0.81 (within- /between-session) for individual absolute CBF and 0.99/0.98 for regional relative CBF. The intraclass correlation coefficients were 0.88/0.77 for absolute CBF and 0.92/0.85 for regional relative CBF. Between-subject variation in CBF was partially contributed by age and physiological parameters. VSI-VSASL demonstrates moderate to excellent reliability for detecting between-subject and between-region variations among healthy subjects, suggesting its merit in clinical applications.

View Presentation Video

Ekin Karasan¹, Jingjia Chen¹, Julian Maravilla¹, Zhiyong Zhang², Chunlei Liu^1,3, and Michael Lustig^1
1Department of Electrical Engineering and Computer Science, University of California, Berkeley, Berkeley, CA, United States, ²School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China, ³Helen Wills Neuroscience Institute, Berkeley, CA, United States

Keywords: Pulse Sequence Design, Perfusion

DiSpect resolves the multi-dimensional displacement spectrum that spins exhibit between tagging and imaging. Previously, we showed that DiSpect can be used to trace blood draining from the capillary bed through the cerebral venous system. This work presents three innovations: 1) Validation of our results with flow phantom experiments and comparison of our in-vivo data with a detailed QSM-venogram. 2) Interleaved imaging to simultaneously probe the deep and superficial veins. 3) Use of a conformal head-cap array for imaging, with higher SNR, allowing dynamic measurement of vein drainage and observation of venous territories across large time scales.

View Presentation Video

Yue Wu^1,2,3, Dehe Weng⁴, Jing An⁴, Rong Xue^1,2,3, Yan Zhuo^1,2,3, and Zihao Zhang^1,2,5
1State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, ²University of Chinese Academy of Sciences, Beijing, China, ³The Innovation Center of Excellence on Brain Science, Chinese Academy of Sciences, Beijing, China, ⁴Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, China, ⁵Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, China

Keywords: Data Acquisition, Blood

GRE-based vascular imaging suffers from the low acquisition efficiency. In this study, we presented a new 3D dual-contrast multishot-EPI based acquisition method called DESPAV for simultaneous MR angiography and venography. Full flow compensation for K-space center line and novel Center-out trajectory was implemented. A reconstruction pipeline was developed to correct for inter-shot phase errors, off-resonance induced artifact, and enable distortion-free multi-shot joint reconstruction. Preliminary results showed that DEPSAV can provide fast intracranial arterial and venous vasculature depiction with comparable contrast and image quality to 3D GRE-based TOF/SWI, while achieve ~3-fold reduction in acquisition time.

View Presentation Video

Renjiu Hu^1,2, Qihao Zhang^2,3, Dominick J. Romano^2,3, and Yi Wang^2,3
1Sibley School of Mechanical and Aerospace Engineering,, Cornell University, Ithaca, NY, United States, ²Department of Radiology, Weill Cornell Medicine, New York, NY, United States, ³Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States

Keywords: Quantitative Imaging, Arterial spin labelling

We compared the quantitative mappings on the simulated the brain arterial spin labeling images with artificial microvasculature structures and perfusion properties. The QTM method gives similar quantification on blood flow as the traditional tracer kinetic model.

View Presentation Video

Zhe Sun^1,2, Chenyang Li^1,2, Marco Muccio¹, Li Jiang¹, and Yulin Ge^1
1Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States, ²Vilcek Institute of Graduate Biomedical Sciences, New York University Grossman School of Medicine, New York, NY, United States

Keywords: Neurofluids, Aging

The choroid plexus (ChP) is a highly vascularized structure that is important in CSF production and waste solute clearance. In this work, USPIO-enhanced 7T imaging was used to detect microvascular changes associated with normal aging. We showed improved susceptibility contrast of ChP vessels and surrounding stromal tissues on high-resolution USPIO-enhanced 2D T2*-weighted MRI. Both age-related sparser vasculature and distended stromal tissues were identified. ChP volume increases with age, whereas the difference between pre-/post-contrast quantitative susceptibility map (QSM) decreases with age (P<0.05); and vascular degenerative change may occur earlier than volume change.

View Presentation Video

Stanley D.T. Pham¹, Jari T. van Vliet², Rick J van Tuijl², Geert Jan Biessels³, Mauro Costagli⁴, Mark A. van Buchem⁵, Oliver Kraff⁶, Arno Villringer⁷, Mark E. Ladd⁸, Jeroen C.W. Siero^2,9, Ludovic de Rochefort¹⁰, and Jaco J.M. Zwanenburg^2
1UMC Utrecht, Utrecht, Netherlands, ²Radiology, UMC Utrecht, Utrecht, Netherlands, ³Neurology, UMC Utrecht, Utrecht, Netherlands, ⁴IMAGO7 Research Foundation, Pisa, Italy, ⁵Neuroradiology, Leiden University Medical Center, Leiden, Netherlands, ⁶Radiology, University Hospital Essen, Essen, Germany, ⁷Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, ⁸German Cancer Research Center (DKFZ), Heidelberg, Germany, ⁹Spinoza Centre for Neuroimaging, Amsterdam, Netherlands, ¹⁰Centre for Magnetic Resonance in Biology and Medicine (UMR 7339), Marseille, France

Keywords: Data Acquisition, High-Field MRI, Harmonization, two dimensional phase contrast

We analyzed multi-center blood flow velocity measurements in perforating arteries from 7T MRI with the two-dimensional phase-contrast (2D-PC) sequence (eight sites, comprising three MRI vendors). Analysis was performed with the software tool Small vessEL MRI MArkers (SELMA). Inter-rater reliability of SELMA was excellent with overall intra-class coefficients for number of vessels (N_detected), mean velocity (V_mean) and velocity pulsatility index (vPI) of at least 0.84 for 2D-PC data from all MRI vendors. Inter-vendor differences were larger than the intra-vendor differences (coefficients of variation: 0.62 vs. 0.39, 0.21 vs. 0.12 and 0.39 vs. 0.12 for N_detected, V_mean and vPI, respectively).

View Presentation Video

Osamu Togao¹, Makoto Obara², Koji Yamashita³, Kazufumi Kikuchi⁴, Tatsuhiro Wada⁵, Chiaki Tokunaga⁵, Ryoji Mikayama⁵, Shota Ishida⁶, Hiroshi Hamano², Lena Vaclavu⁷, Matthias J.P. van Osch⁷, Kim van de Ven⁸, Marc Van Cauteren², and Kousei Ishigami^4
1Department of Molecular Imaging & Diagnosis, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ²Philips Japan, Tokyo, Japan, ³Departments of Radiology Informatics and Network, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ⁴Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ⁵Division of Radiology, Department of Medical Technology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ⁶Department of Radiological Technology, Faculty of medical sciences, Kyoto College of Medical Science, Kyoto, Japan, ⁷C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, ⁸Philips Healthcare, Best, Netherlands

Keywords: Stroke, Perfusion, Arterial Spin Labeling

We have developed a multi-delay PCASL acquisition with a hybrid scheme, combining time-encoded and variable-TR schemes. This hybrid scheme combines the advantage of high SNR obtained with the time-encoded scheme with the timing flexibility of the variable-TR scheme. We investigated the abilities for CBF (cerebral blood flow) and ATT (arterial transit time) quantification in Moyamoya disease. The hybrid scheme provided a higher temporal SNR than the other two schemes. Although slight differences in the CBF and ATT measurements were found between the hybrid and the other two schemes, the differences were acceptable, considering the strong correlations and excellent agreements.
 

View Presentation Video

Keywords: Quantitative Imaging, Neurofluids, Blood-brain barrier water exchange

Contrast-enhanced ASL (CE-ASL) has been proposed as a method for measuring blood-brain barrier water exchange, and is a technique that could be used in conjunction with DCE/DSC-MRI to provide complementary information on brain vasculature. 

 

We demonstrate in this work the clinical feasibility and consistency of the CE-ASL technique in simulations and in healthy volunteers. Using simulations, we characterise the expected accuracy and precision of parameter estimates. We then evaluate the consistency of CE-ASL measurements across six healthy volunteers.

View Presentation Video

JaeGeun Im¹, JunHee Kim¹, and SungHong Park^1
1KAIST, Daejeon, Korea, Republic of

Keywords: Neurofluids, Neurofluids, CSF pulsation, fMRI, CBF, pCASL

To measure CSF pulsation and CBF signals simultaneously with pCASL, we measured the influence of pCASL label pulse on the CSF signal at the craniospinal junction and compared the CSF signal differences and PC stroke volume to estimate CSF pulsation with pCASL. Our results showed that the variability of CSF signals at the nearby position from label pulses was negatively correlated with PC stroke volume. Based on this, the labeling pulse used for CBF tagging in pCASL also can be used for CSF pulsation estimation, and it will allow us to measure CBF and CSF pulsation simultaneously.

View Presentation Video

Pan LIU^1,2, Kimi Piedad Owashi¹, Heimiri Monnier¹, Serge Metanbou³, Cyrille Capel⁴, and Olivier Balédent^1,2
1CHIMERE UR 7516, Jules Verne University of Picardy, Amiens, France, ²Medical Image Processing Department, Amiens Picardy University Hospital, Amiens, France, ³Radiology Department, Amiens Picardy University Hospital, Amiens, France, ⁴Neurosurgery Department, Amiens Picardy University Hospital, Amiens, France

Keywords: Neurofluids, Neurofluids, breathing effects, cerebrospinal fluid, real time phase contrast

The effect of breathing on CSF is not well understood. Real-time phase-contrast MRI can quantify CSF flow continuously. A time-domain multi-parameter analysis method was developed to quantify the effect of free breathing on CSF. It was found that the cardiac period and the average stroke volume of CSF at second-to-third cervical vertebrae level and at the aqueduct were significantly increased during the expiratory phase, while the net flow of CSF was notably decreased.

View Presentation Video

Itamar Terem¹, Nan Wang², Paul Condron³, Kyan Younes⁴, Javid Abderezaei⁵, Berthy Feng ⁶, Hari Kumar^3,7,8, Hillary Vossler⁹, Mehmet Kurt⁵, Katherine L. Bouman ⁶, Elizabeth Mormino⁴, Samantha Holdsworth^3,10, and Kawin Setsompop^1,2
1Electrical Engineering, Stanford, Stanford, CA, United States, ²Radiology, Stanford, Stanford, CA, United States, ³Mātai Medical Research Institute, Tairāwhiti-Gisborne, New Zealand, ⁴Neurology & Neurological Sciences, Stanford, Stanford, CA, United States, ⁵Mechanical Engineering, University of Washington, Seattle, WA, United States, ⁶Computing and Mathematical Sciences (CMS), Cal Tech, Pasadena, CA, United States, ⁷Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand, ⁸General Electric Healthcare, Victoria, Australia, ⁹Neurology, Stanford, Stanford, CA, United States, ¹⁰Faculty of Medical & Health Sciences & Centre for Brain Research, University of Auckland, Auckland, New Zealand

Keywords: Neurofluids, Data Processing, amplified MRI (aMRI), Alzheimer`s disease

Amplified Magnetic Resonance Imaging (aMRI) is a pulsatile brain motion visualization method that delivers ‘videos’ with high contrast and temporal resolution. aMRI has been shown to be a promising tool in various neurological disorders. However, aMRI currently lacks the ability to quantify the sub-voxel motion field in physical units. Here, we introduce a quantitative-aMRI (q-aMRI) algorithm, which quantifies the sub-voxel motion of the 3D aMRI signal and validates its precision using phantom simulations with realistic noise. In-vivo experiments on healthy volunteers demonstrated repeatability of the measurements, and differences in brain motion were observed in subjects with positive/negative amyloid PET.