This presentation describes the novel technique; 4D Flow MRI and its different applications in cardiovascular and cerebrovascular abnormalities..

1. 4D Flow MRI
Dr. Hazem Abu Zeid Yousef
Ass. Prof. of Radiodiagnosis
Assiut University

2. Since its original description in the 1980s (1-4), phase
contrast (PC) magnetic resonance imaging (MRI) has
seen broad clinical acceptance for the visualization and
quantitative evaluation of blood flow in the heart, aorta
and large vessels (5-7). Further development of PC
techniques have allowed for the acquisition of a time-
resolved (CINE), three-dimensional (3D) PC-MRI with
three-directional velocity encoding which is often referred
to as “4D flow MRI” (8).

3. What is 4D flow?
In contrast to standard 2D CINE PC-MRI which allows for the
evaluation of blood flow in a single user selected 2D slice, 4D
flow MRI can provide information on the temporal and spatial
evolution of 3D blood flow with full volumetric coverage of
any cardiac or vascular region of interest (8).
2D MRI of blood flow. Cardiac
mitral valve proplapse in
vertical long axis view. [4]
3D PC-MRI image composed
of a series of 2D slices for
blood flow intensities. [6]

4. The different flow types encountered
in 4D flow are:
1) Stagnant flow
2) Laminar Flow
3) Vortex Flow
4) Turbulent Flow
What is 4D flow?

5. Quantitiveassessment
Flow velocity and flow rate
Wall shear stress (WSS)
Vortex flows
Pressure gradient
Turbulent kinetic energy (TKE)
Pulse wave velocity

6. Pathlines in the aortic arch
of a healthy volunteer from a
dorsolateral view. The movie
shows the velocity color-
coded over the time period
of a heart cycle.
What is 4D flow?
Institut für Diagnostische und Interventionelle Radiologie,
Klinikum Rechts der Isar der TU München - Munich/DE

7. What is 4D flow?
4D Flow MRI carry valuable tools for:
 Diagnosing cardiac and vascular diseases
 Measuring disease severity
 Assessing patient response to medical and
surgical therapy.
 Provides morphological information
 Provides functional information on cardiac
perfusion, myocardial viability, and blood flow.
3D rendering of the heart with blood flow depicted through
streamlines of varying color. The different colors determine
areas of high/low velocity.

8. CVS
CNS
• CHD.
• Thoracic
aorta.
• Cerebral
aneurysms.
• AVM.
Clinical applications of 4D Flow MRI:

10. Congenital heart diseases
Whole heart 4D flow MRI
techniques allow for a non-
invasive comprehensive
assessment of cardiovascular
hemodynamics in the heart and
surrounding great vessels.

14. Assessment of thoracic aorta
Institut für Diagnostische und
Interventionelle Radiologie,
Klinikum Rechts der Isar der
TU München - Munich/DE

15. Characterization of cerebral aneurysms
The 4D-flow MRI demonstrated the influence of
lesion size and morphology on aneurysm
hemodynamics “peak velocity and wall sheer
stress” suggesting the potential of 4D-flow MRI
to assist in the classification of individual
aneurysms (9).

17. Assessment of Arteriovenous Malformation:
Spetzler-Martin grade does not reflect differences in 3D
AVM arterial and venous hemodynamics, and an
individual assessment of AVM hemodynamics may be
needed for improved lesion characterization. Four-
dimensional flow MR imaging may have the potential to
monitor and guide embolization treatment planning
(10).

18. AVM hemodynamics visualized by time-integrated 3D pathlines in 6 of 20 patients.
S.A. Ansari et al. AJNR Am J Neuroradiol 2013;34:1922-1928

20. A limitation of 4D flow MRI is that scan times are between 5 and
20 minutes, and are dependent on the breathing pattern and
heart rate of the patient. Furthermore, imited spatial resolution
restricts analyses in small vessels.
An additional shortcoming of 4D flow MRI is that, for a majority of
clinical studies that have explored the technique, limited
numbers of patients or volunteers have been used (8).

21. Referrences
1.Moran PR. A flow velocity zeugmatographic interlace for NMR imaging in humans. Magn Reson
Imaging 1982;1:197-203.
2. Bryant DJ, Payne JA, Firmin DN, et al. Measurement of flow with NMR imaging using a gradient
pulse and phase difference technique. J Comput Assist Tomogr 1984;8:588-93.
3. Nayler GL, Firmin DN, Longmore DB. Blood flow imaging by cine magnetic resonance. J Comput
Assist Tomogr 1986;10:715-22.
4. Firmin DN, Nayler GL, Klipstein RH, et al. In vivo validation of MR velocity imaging. J Comput
Assist Tomogr 1987;11:751-6.
5. Pelc NJ, Herfkens RJ, Shimakawa A, et al. Phase contrast cine magnetic resonance imaging.
Magn Reson Q 1991;7:229-54.

22. 6. Kilner PJ, Yang GZ, Mohiaddin RH, et al. Helical and retrograde secondary flow patterns in the
aortic arch studied by three-directional magnetic resonance velocity mapping. Circulation
1993;88:2235-47.
7. Kvitting JP, Ebbers T, Wigström L, et al. Flow patterns in the aortic root and the aorta studied
with time-resolved, 3-dimensional, phase-contrast magnetic resonance imaging: implications for
aortic valve-sparing surgery. J Thorac Cardiovasc Surg 2004;127:1602-7.
8. Zoran Stankovic, Bradley D. Allen, Julio Garcia, et al. 4D flow imaging with MRI. Cardiovasc
Diagn Ther 2014;4(2):173-192.
9. Susanne Schnell, Sameer A. Ansari, Parmede Vakil, et al. Three-Dimensional Hemodynamics
in Intracranial Aneurysms: Influence of Size and Morphology. Journal of magnetic resonance
imaging 2014; 39:120–131.
10. S.A. Ansari, S. Schnell, T. Carroll, et al. Intracranial 4D Flow MRI: Toward Individualized
Assessment of Arteriovenous Malformation Hemodynamics and Treatment-Induced Changes.
AJNR Am J Neuroradiol 2013; 34(10):1922-8.