Vessel Wall Imaging

Monday 12 May 2014

Paula Montesinos^1,2, Jonathan R. Polimeni³, Berkin Bilgic³, Stephen F. Cauley³, Manuel Desco^1,2, Reza Nezafat⁴, Lawrence L. Wald³, Elfar Adalsteinsson³, and David E. Sosnovik^3
1Universidad Carlos III, Madrid, Spain, ²Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain, ³Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, MA, United States, ⁴Beth Israel Deaconess Medical Center, Harvard Medical School, MA, United States

The aim of this study was to determine the impact of parallel acquisition on the imaging of coronary plaque under conditions of physiological motion and reduced FOV (inner volume) imaging. Our results indicate that parallel acquisition can improve the resolution of coronary plaque morphology due to a reduction in motion sensitivity. However, the high degree of overlap among coil element profiles in a small FOV focused on the coronary arteries dramatically reduces the potential benefits of using multi-channel receive coils in low SNR scenarios

Khaled Z. Abd-Elmoniem¹, Aylin Unsal¹, Julia B. Purdy¹, Rohan Hazra¹, Colleen Hadigan¹, and Ahmed M. Gharib^1
1National Institutes of Health, Bethesda, MD, United States

HIV early in life may result in premature vasculopathy and cardiovascular disease. To this effect 35 young adults infected with HIV early in life and 11 health controls were included in this study. All subjects underwent coronary vessel wall imaging using TRAPD method at 3T and coronary MDCT. HIV infected subjects had significantly thicker vessel wall than controls as measured by MR without accompanying difference in plaque burden as measured by CT. The former was related to years of antiviral therapy exposure. This MR method provides evidence of vascular injury in antiviral therapy exposure and not associated with coronary atherosclerosis.

Niranjan Balu¹, Jie Sun¹, Daniel S. Hippe¹, David Zhu², Seong-Eun Kim³, John Roberts³, J. Kevin DeMarco², Dennis L. Parker³, David Saloner⁴, Michael V. McConnell⁵, Chun Yuan¹, and Thomas S. Hatsukami^1
1Radiology, University of Washington, Seattle, WA, United States, ²Radiology, Michigan State University, Lansing, MI, United States, ³Radiology, Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States, ⁴Radiology, University of California San Francisco, San Francisco, CA, United States, ⁵Stanford University, CA, United States

Large coverage 3D isotropic vessel MRI has recently been proposed for carotid atherosclerotic plaque characterization. Use of a multicontrast 3D MRI protocol for serial MRI studies of atherosclerosis requires standardized protocols across multiple scanner platforms for use in multicenter studies. Reproducibility of plaque measurements has not been established in a multicenter setting. We demonstrate using patients with 50-79% stenosis that a standardized 3D carotid MRI protocol can provide reproducible measurement across three major scanner platforms (GE, Philips and Siemens). Plaque burden measurements and identification of plaque components showed good to excellent reproducibility comparable to traditional 2D multicontrast vessel wall MRI.

Yibin Xie^1,2, Wei Yu³, Zhaoyang Fan¹, Christopher Nguyen^1,2, Jing An⁴, Zhaoqi Zhang³, and Debiao Li^1,2
1Cedars-Sinai Medical Center, Los Angeles, California, United States, ²University of California, Los Angeles, Los Angeles, California, United States,³Anzhen Hospital, Beijing, China, ⁴Siemens Healthcare, Beijing, China

Diffusion MRI has shown great promises for the detection of lipid-rich necrotic core (LRNC) with excellent image contrast. However current 2D EPI-based methods suffer from poor image quality due to susceptibility-induced artifacts and limited resolution for imaging fine anatomy in plaques. A novel diffusion weighted 3D sequence is developed in this work with features including motion compensation and dark blood. High resolution 3D carotid vessel wall images with excellent image quality were acquired for the first time. Significantly lower ADC values were observed in LRNC than fibrous plaque tissue and normal vessel wall. This technique could be used to detect lipid-rich necrotic core in carotid plaque in vivo without the use of contrast agents.

Jie Sun¹, Niranjan Balu¹, Kiyofumi Yamada¹, Jinnan Wang², Daniel S. Hippe¹, Dongxiang Xu¹, Thomas S. Hatsukami¹, and Chun Yuan^1
1University of Washington, Seattle, WA, United States, ²Philips Research North America, Briarcliff Manor, NY, United States

In vivo quantification of lipid-rich necrotic core size not only reveals prognostic information on patients’ atherothrombotic risk, but also provides a novel means for understanding effects of risk factors on plaque progression. Although a 2D multi-contrast protocol is traditionally used for classifying LRNC areas in advanced plaques, recently developed 3D sequences offer the opportunity to move LRNC quantification from 2D to 3D. This report represents one of the first studies to evaluate the performance of 3D MRI with contrast-enhanced imaging in delineating LRNC areas, which showed good agreement with a histologically validated 2D multi-contrast protocol across various lesion complexities.

Jingwei Zhang^1,2, Thanh D. Nguyen², Xavier J. Candela³, Kory P. Witmer³, Keefe B. Manning^3,4, and Yi Wang^1,2
1Department of Biomedical Engineering, Cornell University, Ithaca, NY, United States, ²Department of Radiology, Weill Cornell Medical College, New York, NY, United States, ³Department of Bioengineering, The Pennsylvania State University, PA, United States, ⁴Department of Surgery, Penn State Hershey Medical Center, Hershey, PA, United States

The purpose of this study was to design and construct an in vitro flow-driven thrombus model and to apply quantitative MR methods to study its T1, T2 and magnetic susceptibility changes in comparison with histological findings.

Zhaoyang Fan¹, Yibin Xie^1,2, Wei Yu³, Antonio H. Conte¹, Xiaoming Bi⁴, Yutaka Natsuaki⁴, Gerhard Laub⁴, Jing An⁵, Prediman K. Shah¹, and Debiao Li^1
1Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²University of California, Los Angeles, CA, United States, ³Anzhen Hospital, Beijing, China,⁴MR R&D Siemens Healthcare, Los Angeles, CA, United States, ⁵MR Collaborations NE Asia, Siemens Healthcare, Beijing, China

The conventional MRI protocol for the characterization of atherosclerotic plaques involves a series of scans that provide multiple contrast weightings. Despite the success in previous investigations, it has some major limitations such as limited slice resolution, substantially long examination time, image registration needed due to interscan motion. This work developed a 3D MRI technique that acquires multiple image sets in a single 5-minute scan with distinct contrast weightings that help simplify compositional analysis in carotid plaques. Preliminary healthy volunteer and patient studies were performed to demonstrate the promise of this technique in a clinical setting.

Linqing Li¹, Luca Biasiolli², Joshua T. Chai³, Matthew D. Robson², Robin P. Choudhury³, Ashok I. Handa⁴, and Peter Jezzard^1
1FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, ²OCMR, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom, ³Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom, ⁴4Nuffield Department of Surgery, University of Oxford, Oxford, United Kingdom

In this study we introduce a new DANTE-prepared 3D FLASH T1 weighted (T1w) sequence (denoted ‘3D-DASH’) that is able to generate 0.6 mm isotropic resolution carotid artery intra-plaque haemorrhage images with an imaging speed better than 2 sec/slice. Imaging efficiency comparisons were also made between the current best 3D black blood (BB) technique, MSDE prepared FLASH (3D-MERGE)and the new 3D-DASH technique.

Bram F Coolen¹, Henk Smit², Dirk HJ Poot^2,3, Gyula Kotek², Stefan Klein², and Aart J Nederveen^1
1Department of Radiology, Academic Medical Center Amsterdam, Amsterdam, Netherlands, ²Biomedical Imaging Group Rotterdam, Erasmus MC Rotterdam, Netherlands, ³Imaging science and Technology, Delft University of Technology, Delft, Netherlands

We present a novel protocol for 3D carotid T1 and T2 mapping using an adapted iMSDE black-blood sequence. The method is validated using phantom experiments and simulations. Feasibility of this approach was tested using in vivo measurements in a healthy volunteer.

Begoña Lavin Plaza¹, Alkystis Phinikaridou¹, Silvia Lorrio Gonzalez¹, Carlos Zaragoza Sanchez², and Rene Botnar^1
1King's College London, London, United Kingdom, ²Centro Nacional Investigaciones Cardiovasculares, Spain

Endothelial cells play a critical role in maintaining vascular homeostasis. However, vascular damage may lead to endothelial dysfunction characterized by decreased bioavailability of nitric oxide, a signalling molecule involved in vasodilatation, with several anti-atherogenic and anti-inflammatory properties. Previous studies have shown that contrast enhanced MRI using gadofosveset, an albumin binding gadolinium contrast agent, can detect endothelial damage, angiogenesis and vascular permeability in different animal models. In this study, we explored whether imaging with gadofosveset could be used to monitor endothelial cell recovery, permeability and vessel wall remodelling in a murine model of aortic endothelial denudation.