ISMRM 23rd Annual Meeting & Exhibition • 30 May - 05 June 2015 • Toronto, Ontario, Canada

Scientific Session • Neurovascular & Stroke 2

Tuesday 2 June 2015

Room 701 B

10:00 - 12:00


Tilak Das, M.D., Ph.D., T.B.A.

10:00 0289.   Perfusion/Diffusion mismatch in stroke: what about the hematocrit?
Benjamin Lemasson1,2, Alexis Broisat3,4, Ligia S. B. Boisserand1,2, Mitra Ahmadi3,4, Sandrine Bacot3,4, Audrey Soubies3,4, Olivier Detante1,5, Catherine Ghezzi3,4, Chantal Rémy1,2, and Emmanuel L. Barbier1,2
1Inserm, U836, Grenoble, -, France, 2Univ. Grenoble Alpes, GIN, Grenoble, -, France, 3Inserm, U1039, Grenoble, -, France, 4Univ. Grenoble Alpes, Radiopharmaceutiques Biocliniques, Grenoble, -, France, 5CHU de Grenoble, GIN, Grenoble, -, France
MRI and molecular imaging techniques were associated to map the perfusion (CBF)/diffusion (ADC) mismatch and the local hematocrit level (Hct) of rats during actute stroke. The stroke lesion drawn on the CBF maps were significantly larger than the ones drawn on the ADC maps which were themselves significantly larger than the ones drawn on the Hct maps (ROIs sizes: CBF>ADC>Hct). The mismatch between CBF and Hct suggests that plasmatic and red blood cell flows are not equivalent during acute stroke. The ADC/Hct mismatch might be used to determine a new region of tissue, which could be able to recover.

10:12 0290.   Towards Characterization of the Cerebral Venous Vessel Network using QSM: Extraction of Vessel Radii and Lengths
Barthélemy Serres1, Andreas Deistung1, Andreas Schäfer2, Marek Kocinski3, Andrzej Materka3, and Jürgen Reichenbach1
1Medical Physics Group, Institute for Diagnosis and Interventional Radiology, University Hospital Jena - Friedrich Schiller University Jena, Jena, Germany,2Max Plank Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 3University of Lodz, Lodz, Poland

Characterizing the brain venous network with quantitative data is mandatory for radiologists to better diagnose and plan surgical interventions. The venous blood vessels can be depicted in high-spatial detail and accuracy with quantitative susceptibility maps with MR Imaging1. This technique grants access to the whole brain venous network. But, the characterization of the topology of this vessels network is the first step toward providing novel computer aided-tools which could be able to automatically analyze the venous network and detects abnormalities. In this contribution, we are relying on our previous work of susceptibility maps segmentation to present an approach for quantifying the cerebral venous vessel network from QSM Images

10:24 0291.   Estimation of a PET AIF using DSC MRI
John Lee1, Colin Derdeyn1, and Joshua Shimony1
1Washington University School of Medicine, Saint Louis, MO, United States

Bayesian modeling and parameter estimation predict arterial input functions for H2[15O] PET using information from whole-brain PET tracer inflows and DSC MRI. Validation of normalized arterial input functions was achieved in 18 patients with clinically significant cerebrovascular disease. The approach may be a useful adjunct to perfusion studies on the new generation of PET/MRI scanners.

10:36 0292.   High-Speed, High-Resolution Whole-Head Sparse Contrast-Enhanced MR Angiography - permission withheld
Aurelien F Stalder1, Harald H Quick2,3, Michael O Zenge4, Peter Schmitt1, Qiu Wang5, Marc Schlamann6, Stefan Maderwald2, Mariappan Nadar5, and Michaela Schmidt1
1Siemens Healthcare, Erlangen, Germany, 2Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Germany, 3High Field and Hybrid MR Imaging, University Hospital Essen, Germany, 4Siemens Healthcare, NY, United States, 5Imaging and Computer Vision, Siemens Corporate Technology, NJ, United States, 6Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Germany

Asymptotic incoherence and sparsity that can be obtained with large matrix sizes have been shown to play a key role in sparse data sampling. Based on this, a sequence and reconstruction prototype for high-resolution CEMRA was implemented on a standard clinical scanner. Whole head CEMRA with isotropic 0.7 mm resolution in just 10 s acquisition time was performed in 10 patients. The shown excellent image quality with 30-fold undersampling demonstrates the potential of sparse CEMRA for faster acquisition and/or resolution enhancement and confirms the sparse sampling theory indicating the potential of sparse MRI for high-resolution imaging.

10:48 0293.   Exploring the Limits of Resolution in Contrast Enhanced MRA with Ultrashort Echo Time Imaging
Kevin Michael Johnson1, Yijing Wu1, and Patrick A Turski2
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Radiology, University of Wisconsin-Madison, Madison, WI, United States

Imaging at high spatial resolution is requisite for imaging the intracranial vasculature; however, achieving high spatial resolution is challenging due to competing factors including SNR, scan time, and artifacts. In particular, as the resolution increases the need for flow compensation increases which can lead to lower SNR and increases sensitivity to higher order motion effects. In this work, we investigate high spatial resolution angiography utilizing accelerated Contrast Enhanced (CE) ultra-short echo (UTE) imaging, and demonstrate high resolution imaging of the vascular system with 0.57mm isotropic resolution.

11:00 0294.   Detection of intracranial vessel wall lesions in an elderly asymptomatic population using 7T MRI
A.A. Harteveld1, A.G. van der Kolk1, H.B. van der Worp2, N. Dieleman1, F. Visser1,3, P.R. Luijten1, J.J.M. Zwanenburg1,4, and J. Hendrikse1
1Department of Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, Netherlands, 3Philips Healthcare, Best, Netherlands, 4Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands

Development of atherosclerotic lesions occurs silently over a long period, before they become symptomatic. Most studies have attempted to target ICAD when it is already symptomatic. Additional information regarding the prevalence of ICAD in the asymptomatic population would provide us with better insight in its development. The aim of this study was to assess the presence of intracranial vessel wall lesions in an asymptomatic population using intracranial vessel wall MR imaging at 7.0 tesla. Intracranial vessel wall lesions were found in all elderly asymptomatic subjects. The total number of identified vessel wall lesions was high, especially for the posterior circulation.

11:12 0295.   Cerebral venous thrombosis: direct thrombus imaging with sub-millimeter isotropic resolution dark-blood MRI
Zhaoyang Fan1, Qi Yang1,2, Xiaofeng Qu1,3, Yibin Xie1,4, Guoxi Xie5, Tianyi Qian6, Xiaoming Bi7, Yutaka Natsuaki7, and Debiao Li1
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States, 2Radiology, Xuanwu Hospital, Beijing, China,3Radiology, The Second Hospital OF Dalian Medical University, Dalian, China, 4Bioengineering, University of California, Los Angeles, California, United States, 5Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Guangdong, China, 6MR Collaboration NE Asia, Siemens Healthcare, Beijing, China, 7MR R&D, Siemens Healthcare, Los Angeles, California, United States

Cerebral venous thrombosis (CVT) is a disorder potentially leading to devastating disability and even death if not timely diagnosed and treated. Diagnosis is challenging with the current clinical imaging modalities due to various image artifacts and the variation in venous anatomy. We hypothesized that high-spatial-resolution dark-blood MRI, commonly used for artery wall imaging, may be a useful tool. In this work, a T1-weighted DANTE-prepared 3D TSE technique was developed to provide direct visualization of thrombus and surrounding anatomic structures in cerebral venous system. Our preliminary clinical study demonstrated that the technique may outweigh TOF MRV in diagnosing CVT.

11:24 0296.   A one-stop-shop for hemodynamic imaging in Moyamoya disease
Peiying Liu1, Babu G Welch2, Darlene King2, Yang Li1, Marco Pinho1,3, and Hanzhang Lu1
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, 2Neurological Surgery Clinic, University of Texas Southwestern Medical Center, Dallas, Texas, United States, 3Department of Radiology, University of Texas Southwestern Medical Center, Texas, United States

Brain stenotic diseases such as moyamoya disease (MMD) are characterized by diminished cerebrovascular reserve. In this work, we proposed a “one-stop-shop” method for hemodynamic imaging in cerebrovascular diseases, in which venous cerebral blood volume (vCBV) and cerebrovascular reactivity (CVR), as well as a response time (RT) map reflecting kinetic properties are obtained in a single scan of about 9 minutes without need for radiation exposure of administration of exogenous contrast agents. We showed that MMD patients have diminished vasodilatory function while their baseline vCBV was intact. This method may be a practical and valuable method in cerebrovascular diseases.

11:36 0297.   Intravoxel Incoherent Motion Imaging exposes abnormal parenchyma and microvasculature in cerebral small vessel disease
Sau May Wong1, Eleana Zhang2, Frank C.G. Bussel1, Julie E.A. Staals2, Cécile R.L.P.N. Jeukens1, Paul A.M. Hofman1, Robert J. van Oostenbrugge2, Walter H. Backes1, and Jacobus F.A. Jansen1
1Radiology, Maastricht University Medical Center, Maastricht, Limburg, Netherlands, 2Neurology, Maastricht University Medical Center, Maastricht, Limburg, Netherlands

Cerebral small vessel disease(cSVD) affects the small vessels in the brain, which can potentially lead to ischemic stroke and dementia. The pathophysiology remains unclear. Intravoxel incoherent motion imaging(IVIM) was performed to examine both the parenchymal and vascular microstructure in cSVD. Significant higher microvascular perfusion fraction(f) and parenchymal diffusivity(D) were found for patients in normal appearing brain tissue compared with controls. Higher f might be related to more tortuous vessels and higher D might imply loss of parenchymal microstructural integrity in cSVD. We demonstrate the potential of IVIM in providing novel information of the brain tissue in cSVD.

11:48 0298.   
Transient cerebral ischemia in rodents exposed to chronic intermittent hypoxia
Bianca Gonzales Cerqueira1, Yuhao Sun1, Shiliang Huang1, Glenn Toney2, and Timothy Q Duong1
1Research Imaging Institute, Univ. of TX Health Science Center, San Antonio, TX, United States, 2Physiology, Univ. of TX Health Science Center, TX, United States

There is controversy in literature on whether prior exposure to chronic intermittent hypoxia (CIH), a model of sleep apnea, is detrimental to or neuroprotective against transient cerebral ischemia. In this study, we exposed rats to 14-day CIH of 10% O2 and induced 60-minute cerebral ischemia using middle cerebral artery occlusion. CBF, ADC, and T2 lesion volumes were calculated up to 14 days post stroke. CBF stroke lesion volumes at 30 minutes were the same between controls and CIH-exposed animals. ADC and T2 lesion volumes were significantly larger in the CIH-exposed group as compared to controls in all time points studied.