Benjamin Lemasson^1,2, Alexis Broisat^3,4, Ligia S. B. Boisserand^1,2, Mitra Ahmadi^3,4, Sandrine Bacot^3,4, Audrey Soubies^3,4, Olivier Detante^1,5, Catherine Ghezzi^3,4, Chantal Rémy^1,2, and Emmanuel L. Barbier^1,2
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.

Barthélemy Serres¹, Andreas Deistung¹, Andreas Schäfer², Marek Kocinski³, Andrzej Materka³, and Jürgen Reichenbach^1
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

John Lee¹, Colin Derdeyn¹, and Joshua Shimony^1
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.

Aurelien F Stalder¹, Harald H Quick^2,3, Michael O Zenge⁴, Peter Schmitt¹, Qiu Wang⁵, Marc Schlamann⁶, Stefan Maderwald², Mariappan Nadar⁵, and Michaela Schmidt^1
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.

Kevin Michael Johnson¹, Yijing Wu¹, and Patrick A Turski^2
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.

A.A. Harteveld¹, A.G. van der Kolk¹, H.B. van der Worp², N. Dieleman¹, F. Visser^1,3, P.R. Luijten¹, J.J.M. Zwanenburg^1,4, and J. Hendrikse^1
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.

Zhaoyang Fan¹, Qi Yang^1,2, Xiaofeng Qu^1,3, Yibin Xie^1,4, Guoxi Xie⁵, Tianyi Qian⁶, Xiaoming Bi⁷, Yutaka Natsuaki⁷, and Debiao Li^1
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.

Peiying Liu¹, Babu G Welch², Darlene King², Yang Li¹, Marco Pinho^1,3, and Hanzhang Lu^1
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.

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. Jansen^1
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.

Bianca Gonzales Cerqueira¹, Yuhao Sun¹, Shiliang Huang¹, Glenn Toney², and Timothy Q Duong^1
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.