SCMR 23rd Annual Scientific Sessions

SCMR/ISMRM Co-Provided Workshop

SCMR/ISMRM Co-Provided Workshop: Session 2: Multidimensional, Multiparametric, and Multimodality Imaging

6 - 5D flow MRI for cardiac and respiratory motion-resolved 3D blood flow dynamics in adult patients and pediatric patients with congenital heart disease

Wednesday, February 12, 2020

11:32 AM – 11:44 AM

Location: Canary 3 & 4

Background: Clinical implementation of 4D flow MRI is still limited by long scan times, cumbersome ECG gating, and respiration control. Moreover, most 4D flow methods are navigator-gated and cannot resolve respiratory hemodynamics. Di Sopra et al. previously described a 5D fully self-gated, free-running framework, for efficient cardiac (card) and respiratory (resp) motion-resolved functional imaging of the heart.^1-3 We subsequently proposed a novel expansion of this technique to 3D flow-sensitivity—5D flow MRI.⁴ This study aimed to evaluate the performance of 5D flow MRI in assessing cardiac- and respiratory-resolved 3D hemodynamics in vivo in a standard clinical setting.

Methods: A prototype 5D flow MRI sequence was evaluated at 1.5T (MAGNETOM Aera, Siemens Healthcare) in 20 prospectively recruited adult patients (2F, age=48.6±16.7 y, Venc=150-400 cm/s, temp. res.=35.1-48.4 ms, spatial res.=2.3-2.5 mm³), with a variety of clinical imaging indications (13 BAV, 2 mechanical Ao valve, 2 CVA, 3 AAo aneurysm), and 3 pediatric patients (age=12-14 y) with complex congenital heart disease (PAPVR, Fontan, ventricular septal defect). 5D flow data were continuously collected for a predefined scan time following 3D radial spiral-phyllotaxis sampling pattern with 3D flow sensitivity. Interleaved self-gating projections were used for retrospective binning of the data (kx-ky-kz-card-resp-flow), and reconstructed using a compressed sensing framework.^1,2 All patients received a same-scan conventional 4D flow MRI of the thoracic aorta (GRAPPA R=2, navigator gating) as part of their standard-of-care imaging protocol. The thoracic aorta and caval veins were evaluated for conventional 4D flow comparisons and respiration-resolved hemodynamics, respectively. Time-resolved flow curves were used to derive net flow at multiple planar locations.

Results: 5D flow whole-heart scan times were significantly shorter than conventional 4D flow of the thoracic aorta (7:39±0:21 vs. 9:52±3:10 min, p< 0.01). Aortic comparisons demonstrated overall good agreement in qualitative evaluation of hemodynamics (Fig. 1A). Quantitative conventional comparisons revealed significantly increased peak velocity in the AAo, and decreased in the Arch and DAo using 5D flow (12%±10%, -7%±11%, -8%±11%, respectively, p< 0.02). Respiratory-resolved caval evaluation revealed significant differences between respiratory phases in net flow in IVC1 and IVC2 (p=0.0045, p=0.0001) and in SVC2 (p=0.0160, Table 1). Pediatric analyses demonstrated notable hemodynamic differences between respiratory phases (Fig. 2).

Conclusion: 5D flow MRI can capture whole-heart cardiac and respiratory motion-resolved 3D hemodynamics in the clinical setting in a predictable scan time. 5D flow values showed reasonable agreement with 4D flow, but increased AAo peak velocities might be due to physiologic or abnormal background phase effects. Future studies will explore these limitations and include increased recruitment of respiration-sensitive patients (i.e. Fontan).

Presenting Author(s)

Liliana Ma

MD/PhD student
Northwestern University

Disclosure: Disclosure information not submitted.

Primary Author(s)

Liliana Ma

MD/PhD student
Northwestern University

Disclosure: Disclosure information not submitted.

Co-Author(s)

JY

Jérôme Yerly, PhD

University Hospital (CHUV) and University of Lausanne (UNIL)

Disclosure: Disclosure information not submitted.
Lorenzo Di Sopra, DO, MSc

PhD student
University Hospital (CHUV) and University of Lausanne (UNIL)

Disclosure: Disclosure information not submitted.
Davide Piccini, PhD

Senior Scientist
Siemens Healthcare Switzerland

Disclosure: Disclosure information not submitted.
CR

Christopher W. Roy, PhD, MSc

Postdoctoral Researcher
University Hospital (CHUV) and University of Lausanne (UNIL)

Disclosure: Disclosure information not submitted.
JB

Julie Blaisdell, MSc

Research Project Manager
Northwestern University

Disclosure: Disclosure information not submitted.
James Carr, MD

Knight Family Professor of Cardiac Imaging
Northwestern Memorial Hospital

Disclosure: Bayer: Consulting Fees (e.g., advisory boards), Grant/Research Support, Speaker/Honoraria; Guerbet: Grant/Research Support; Siemens Healthcare: Consulting Fees (e.g., advisory boards), Grant/Research Support, Other Financial or Material Support, travel
CR

Cynthia K. Rigsby, MD

Professor of Radiology and Pediatrics
Ann & Robert H. Lurie Children's Hospital of Chicago

Disclosure: Disclosure information not submitted.
Daniel Kim, PhD

Professor
Northwestern University

Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.
Michael Markl, PhD

Professor & Vice Chair for Research
Northwestern University

Disclosure: Circle Cardiovascular Imaging: Consulting Fees (e.g., advisory boards), Grant/Research Support; Cryolife Inc (Individual(s) Involved: Self, Products/Services: grant): Grant/Research Support; NXT Biomedical (Individual(s) Involved: Self, Products/Services: Consultant): Consulting Fees (e.g., advisory boards); Siemens Healthcare: Grant/Research Support
Matthias Stuber, PhD

Professor
University Hospital (CHUV) and University of Lausanne (UNIL)

Disclosure: Disclosure information not submitted.