Caroline Colbert¹, Michael A. Thomas², Ran Yan³, Aleksandra Radjenovic⁴, J. Paul Finn^1,5, Peng Hu^1,3,5, and Kim-Lien Nguyen^1,2,5
1Physics and Biology in Medicine Graduate Program, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States, ²Division of Cardiology, UCLA David Geffen School of Medicine, Los Angeles, CA, United States, ³Department of Radiology, UCLA David Geffen School of Medicine, Los Angeles, CA, United States, ⁴Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom, ⁵Diagnostic Cardiovascular Imaging Laboratory, Department of Radiological Sciences, UCLA David Geffen School of Medicine, Los Angeles, CA, United States

We optimized and tested a two-compartment water exchange model for fractional myocardial blood volume (fMBV) quantification. Nine healthy swine and one swine model with single-vessel coronary stenosis underwent MOLLI T1 imaging at 3.0 T following multiple individual ferumoxytol infusions. Healthy normal swine showed a mean mid-ventricular fMBV of 7.2 ± 1.4% and water exchange rate of 11.3 ± 5.1 s^-1. In one swine model with artificially‑induced single-vessel coronary stenosis, quantitative pixel-wise fMBV showed regional differences in hypoperfused relative to perfused regions. This study demonstrates the feasibility of fMBV estimation using multi-dose ferumoxytol‑enhanced MRI with a two-compartment water exchange model.

Dengrong Jiang^1,2, Zixuan Lin^1,2, Peiying Liu¹, Sandeepa Sur¹, Cuimei Xu¹, Kaisha Hazel¹, George Pottanat¹, Jacqueline Darrow³, Jay J. Pillai^1,4, Sevil Yasar⁵, Paul Rosenberg⁶, Abhay Moghekar³, Marilyn Albert³, and Hanzhang Lu^1,2,7
1The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ²Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ³Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁴Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁵Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁶Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁷F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD, United States

Alzheimer’s disease, vascular cognitive impairment and their concurrence represent the most common types of cognitive dysfunction. There exists a considerable overlap in their clinical symptoms and neuroimaging features, and we still lack effective tools for their differential diagnosis. This work demonstrated that cerebral oxygen-extraction-fraction (OEF) was differentially affected by Alzheimer’s (decrease OEF) and vascular (increase OEF) pathology. In individuals with low vascular risks, lower OEF was associated with worse cognitive performance and greater amyloid burden. In impaired patients, higher OEF was associated with great vascular risk factors. These findings suggest OEF can be useful in etiology-based diagnosis of cognitive impairment.

James W. MacKay^1,2, Joshua Kaggie¹, Graham M. Treece³, Stephen M. McDonnell⁴, Wasim Khan⁴, Alexandra R. Roberts^5,6, Rob L. Janiczek⁵, Martin J. Graves¹, Tom D. Turmezei^2,7, Andrew W. McCaskie⁴, and Fiona J. Gilbert^1
1Department of Radiology, University of Cambridge, Cambridge, United Kingdom, ²Norwich Medical School, University of East Anglia, Norwich, United Kingdom, ³Department of Engineering, University of Cambridge, Cambridge, United Kingdom, ⁴Department of Surgery, University of Cambridge, Cambridge, United Kingdom, ⁵Clinical Imaging, GlaxoSmithKline, London, United Kingdom, ⁶Antaros Medical, Uppsala, Sweden, ⁷Department of Radiology, Norfolk & Norwich University Hospital, Norwich, United Kingdom

Conventional MRI outcome measures for cartilage in knee osteoarthritis (OA) clinical studies lack responsiveness and require time-consuming manual analysis. Here we validate and clinically implement a semiautomatic surface-based approach termed 3D Cartilage Surface Mapping (3D-CaSM) which overcomes these issues. Validation data demonstrate comparable bias, precision, repeatability and reproducibility to expert manual segmentation (current standard) but with >10 fold reduction in analysis time. Clinical data indicate improved sensitivity to change in one observational and two interventional (exercise, knee joint distraction) studies.

Beata Bachrata^1,2, Bernhard Strasser^1,3, Wolfgang Bogner¹, Albrecht Ingo Schmid⁴, Radim Korinek⁵, Martin Krššák^1,2,6, Siegfried Trattnig^1,2, and Simon Daniel Robinson^1,7,8
1High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, ²Karl Landsteiner Institute for Clinical Molecular MR in Musculoskeletal Imaging, Vienna, Austria, ³Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, ⁴High Field MR Centre, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, ⁵Institute of Scientific Instruments of the CAS, Brno, Czech Republic, ⁶Department of Internal Medicine III, Division of Endocrinology and Metabolism, Medical University of Vienna, Vienna, Austria, ⁷Centre of Advanced Imaging, University of Queensland, St. Lucia, Australia, ⁸Department of Neurology, Medical University of Graz, Graz, Austria

Imaging of body regions containing a significant amount of fat is adversely affected by chemical shift artefacts. We propose a new fat-water imaging method that uses spectrally selective dual-band excitation and CAIPIRINHA to generate separate images of fat and water simultaneously as well as chemical shift-corrected, recombined fat-water images. Gradient-echo and turbo spin-echo variants of this Simultaneous Multiple Resonance Frequency Imaging (SMURF) approach yielded fat-water separation which was similar to or better than state-of-the-art techniques in the knee, breasts and abdomen and generated recombined fat-water images in which chemical shift effects were fully eliminated.

Keshav Datta¹ and Daniel Spielman^1
1Department of Radiology, Stanford University, Stanford, CA, United States

Metabolic imaging using hyperpolarized [2-¹³C]Pyruvate has the potential to simultaneously probe glycolysis and Kreb’s cycle, but one of its major limitations is the difficulty in imaging [2-¹³C]Lactate. The peak-splitting induced by the J-coupling between the C₂ carbon and its attached proton causes ghosting and blurring artifacts, depending on the k-space trajectory. We propose two novel techniques, the first a two-shot approach combining in-phase and quadrature images acquired at echo times differing by 1/2J and the second a single-shot method employing a highly narrowband radiofrequency excitation pulse that images a single peak from the doublet, to resolve the J-modulated artifacts.

Nan Wang^1,2, Yibin Xie¹, Zhaoyang Fan^1,2, Sen Ma^1,2, Rola Saouaf³, Yu Guo^1,4, Stephen L. Shiao^5,6, Anthony G. Christodoulou^1,2, and Debiao Li^1,2
1Biomedical Imaging Research Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States, ²Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, ³Department of Imaging, Cedars Sinai Medical Center, Los Angeles, CA, United States, ⁴Department of Radiology, Tianjin First Central Hospital, Tianjin, China, ⁵Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ⁶Biomedical Sciences, Division of Immunology, Cedars-Sinai Medical Center, Los Angeles, CA, United States

DCE MRI is an important technique for diagnosing breast cancer, but continues to face technical challenges and gadolinium deposition concerns. In this work, we proposed a low-dose Multitasking DCE (LD-MT-DCE) technique, enabling dynamic-T1-mapping based quantitative characterization of tumor blood flow and vascular properties with whole-breast coverage, a spatial resolution of 0.9×0.9×1.1mm³, and a temporal resolution of 1.4 s using only 20% gadolinium dose. An in vivo study showed excellent image quality and repeatability (ICC≥0.99) for LD-MT-DCE and consistent diagnosis to standard-dose clinical DCE. The kinetic parameters showed significant differences between normal breast tissue, and benign and malignant tumors.