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

Scientific Session • Let It Flow

Tuesday 2 June 2015

Room 714 A/B

16:00 - 18:00


Susanne Schnell, Ph.D., T.B.A.

16:00 0449.   
Correction of background phase offsets in phase-contrast MRI using concurrent magnetic field monitoring.
Daniel Giese1,2, Bertram Wilm2,3, Julia Busch2, David Maintz1, Christoph Barmet2,3, Klaas Pruessmann2, and Sebastian Kozerke2
1Radiology, University Hospital Cologne, Cologne, Germany, 2Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 3Skope Magnetic Resonance Technologies, Zurich, Switzerland

Concurrent magnetic field monitoring is used to analyze and correct for eddy-current related background phase offsets in phase-contrast MRI. It is demonstrated that 3rd order correction results in residual background offsets of less than 0.6 cm/s. Using simultaneous acquisition of field monitoring and imaging data, temperature dependent changes in background phase offsets are inherently captured and corrected for.

16:12 0450.   
Reproducibility of Phase-Contrast MRI in the Coronary Artery: Towards Noninvasive Pressure Gradient Measurement and Quantification of Fractional Flow Reserve
Zixin Deng1,2, Yang Qi2, Xiaoming Bi3, Zhaoyang Fan2, and Debiao Li1,2
1Bioengineering, University of California, Los Angeles, Los Angeles, California, United States, 2Biomedical Imaging Research Institute (BIRI), Cedars-Sinai Medical Center, Los Angeles, California, United States, 3R&D, Siemens Healthcare, Los Angeles, California, United States

Fractional Flow Reserve (FFR) invasively evaluates the functional severity of an intermediate stenosis by measuring the stenotic pressure drop via catheterization. Noninvasive pressure measurements using PC-MRI and Navier-Stokes equations have been shown in the aorta, carotid and renal arteries. In this study, the feasibility and reproducibility of PC-MRI and noninvasive pressure calculations were evaluated in the coronary arteries to establish the robustness of noninvasive FFR measurement using MRI. Excellent correlations were observed in the through-plane and slightly lower in the in-plane velocities between the repeated acquisitions. The noninvasive pressure values in healthy subjects were near zero, as expected.

16:24 0451.   
Soft-gated accelerated Cartesian 4D flow imaging with intrinsic navigation
Joseph Y Cheng1,2, Marcus T Alley2, Tao Zhang1,2, Peng Lai3, Jonathan I Tamir4, Martin Uecker4, John M Pauly1, Michael Lustig4, and Shreyas S Vasanawala2
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, 4Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, United States

Time-resolved phase contrast MRI (4D flow) can quantify cardiac function and flow. The technique may even permit complex anatomical assessment, thus comprising a comprehensive exam in a single scan. Unfortunately, artifacts from respiratory motion compromise this ability. Therefore, we developed a simple method to measure motion using readily available navigation information from the flow encoding gradients. We incorporated and modified a variable-density sampling and radial view-ordering scheme to facilitate motion correction and compressed sensing methods. Lastly, we integrated soft-gating to the compressed sensing and parallel imaging reconstruction. These motion-compensation approaches help improve the reliability and resolution of 4D flow imaging.

16:36 0452.   
Aortic stiffness, cardiac energetic, systolic and diastolic function in healthy ageing.
Jehill D Parikh1, Kieren G Hollingsworth1, Andrew M Blamire1, and Guy MacGowan2
1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, 2Cardiology, Freeman Hospital, Newcastle Upon Tyne, Tyne and Wear, United Kingdom

Aorta rapidly expands during a ventricular contraction accommodating the majority (50% or more) of the stroke volume. Aortic stiffness increases with age, and is regarded as an independent risk factor in the development of cardiovascular disease. Additionally, normal ageing is characterized by age-related diastolic dysfunction, altered systolic strains and impaired myocardial energetics. In this study we explore associations between age-related increase in aortic stiffness and cardiac energetics and left ventricular function. Such associations may provide important insights into how normal ageing affects the heart, which may allow development of potential treatments to attenuate this process.

16:48 0453.   
3D quantification of Vorticity and Helicity from 4D flow data using finite element interpolations
Julio Sotelo1,2, Jesus Urbina1,3, Israel Valverde4,5, Cristian Tejos1, Pablo Irarrazaval1, Daniel E. Hurtado2,6, and Sergio Uribe1,3
1Biomedical Imaging Center, Electrical Engineering Department, Pontificia Universidad Catolica de Chile, Santiago, RM, Chile, 2Structural and Geotechnical Engineering Departement, Pontificia Universidad Catolica de Chile, Santiago, RM, Chile, 3Radiology Department, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile, 4Pediatric Cardiology Unit, Hospital Virgen del Rocio, Seville, Spain, 5Cardiovascular Pathology Unit, Institute of Biomedicine of Seville (IBIS), Hospital Virgen del Rocio, Seville, Spain, 6Biomedical Engineering Group, Pontificia Universidad Catolica de Chile, Santiago, Chile

Several methods have been proposed to analyze hemodynamic parameters from 4D flow data, including vorticity and helicity. However the analysis is usually qualitative and performed in reformatted 2D planes. In this work we propose a novel method that integrates advanced image processing strategies and computational techniques based on finite element interpolations to obtain a 3D quantitative map of vorticity, helicity density and relativity helicity density derived from 4D flow data sets obtained from volunteers and patients.

17:00 0454.   
Reproducibility of Advanced Velocity and Wall Shear Stress Quantification Techniques Derived From 4D Flow MRI in the Pathological Aorta
Pim van Ooij1, Wouter V Potters1, Jeremy D Collins2, James C Carr2, S Chris Malaisrie3, Patrick M McCarthy4, Michael Markl2, and Alex J Barker2
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Radiology, Northwestern University, Chicago, IL, United States, 3Medicine-Cardiology, Northwestern University, Chicago, IL, United States, 4Division of Cardiac Surgery, Northwestern University, Chicago, IL, United States

Recently a technique was developed to visualize patient-specific abnormal aortic velocity and wall shear stress (WSS) for guidance in tissue resection surgery for BAV disease. In this study, the reproducibility of the technique is investigated by comparing abnormal velocity and WSS of baseline and follow-up (separated by appr. a year) 4D flow MRI in 24 BAV patients and 15 tricuspid aortic valves and aortic dilatation (TAV+D). No significant differences were found in aortic diameter, peak velocity or abnormal velocity and WSS. Therefore, the technique is stable.

17:12 0455.   
4D Flow based Characterization of Aortic Morphometry and Flow Parameters: Impact of Age, Aortic Dilatation and Valve Morphology
Julio Garcia1, Alex J Barker1, Ian Murphy1, Kelly B Jarvis1, Alex L Powell1, Susanne Schnell1, Jeremy Collins1, James Carr1, S Chris Malaisrie2, and Michael Markl1,3
1Radiology, Northwestern University, Chicago, Illinois, United States, 2Division of Cardiothoracic Surgery, Northwestern University, Chicago, Illinois, United States, 3Biomedical Engineering, Northwestern University, Evanston, Illinois, United States

Aortic diameter and peak velocity are important metrics for the characterization of aortic disease. However, these parameters are typically evaluated at selected locations along the aorta and are thus subject to observer variability and may miss the true maximum aortic diameter or velocity. The purpose of this study was to apply volumetric 4D flow MRI for the simultaneous assessment of aorta morphometry and flow parameters along the entire volume of the thoracic aorta in patients with aortic dilation.

17:24 0456.   Longitudinal Monitoring of Hepatic Blood Flow in patients with portal hypertension before and after TIPS implantation with 4D Flow MRI
Peter Bannas1,2, Alejandro Roldán-Alzate1, Kevin M Johnson3, Michael A Woods1, Utaroh Motosugi1, Oliver Wieben3, Scott B Reeder1,3, and Harald Kramer1,4
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, 3Medical Physics, University of Wisconsin-Madison, WI, United States, 4Radiology, Ludwig-Maximilians-University Hospital, Munich, Bavaria, Germany

Transjugular intrahepatic portosystemic shunt (TIPS) is non-surgical method of portal decompression to treat major complications of portal hypertension. Currently, the combination of Doppler ultrasound and invasive portosystemic pressure measurements are applied to monitor patients before and after TIPS placement. An alternative operator-independent and non-invasive technique would be highly desirable. In this study we demonstrate the feasibility of 4D-flow MRI for qualitative and quantitative analyses of hepatic blood flow before and then 2 and 12 weeks after TIPS placement. 4D flow MRI is feasible for longitudinal hemodynamic monitoring of the blood flow in the portal vein and the TIPS stent.

17:36 0457.   Quantitative assessment of splenic hemodynamics at 4D flow MRI in the evaluation of thrombocytopenia: A pilot study in cirrhotic patients with portal hypertension
Jeremy Douglas Collins1, Jad Bou Ayache2, Edouard Semaan3, Riad Salem4, James Christian Carr3, Michael Markl3, and Zoran Stankovic5
1Radiology, Northwestern University, Chicago, IL, United States, 2Radiology, Icahn School of Medicine at Mount Sinai, New York, United States, 3Northwestern University, Illinois, United States, 4Radiology, Northwestern University, Illinois, United States, 5Radiology, University Hospital, Freiberg, Germany

There is a clinical need for a non-invasive diagnostic test to assess spleen function. Quantitative splenic hemodynamics, assessed using non-contrast 4D flow MRI, demonstrate differences between patients with severe and mild thrombocytopenia and may be useful to distinguish patients with hypersplenism associated thrombocytopenia from those with thrombopoetin deficiency.

17:48 0458.   Highly Accelerated Intracranial 4D Flow MRI with CIRcular Cartesian UnderSampling (CIRCUS)
Jing Liu1, Farshid Faraji1, Sarah Kefayati1, Henrik Haraldsson1, and David Saloner1,2
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Radiology Service, VA Medical Center, San Francisco, CA, United States

An effective k-space undersampling scheme for 3D Cartesian acquisition combined with compressed sensing and parallel imaging has successfully been implemented and applied to intracranial 4D flow MRI. Our preliminary results demonstrated that the proposed approach achieved high image quality and accurate velocity imaging with largely accelerated acquisition (R=7).