Velocity mapping of the aortic flow at 9.4 T in healthy mice and mice with induced heart failure using time-resolved three-dimensional phase-contrast MRI (4D PC MRI).
OBJECTIVE
In this study, we established and validated a time-resolved three-dimensional phase-contrast magnetic resonance imaging method (4D PC MRI) on a 9.4 T small-animal MRI system. Herein we present the feasibility of 4D PC MRI in terms of qualitative and quantitative flow pattern analysis in mice with transverse aortic constriction (TAC).


METHODS
4D PC FLASH images of a flow phantom and mouse heart were acquired at 9.4 T using a four-point phase-encoding scheme. The method was compared with slice-selective PC FLASH and ultrasound using Bland-Altman analysis. Advanced 3D streamlines were visualized utilizing Voreen volume-rendering software.


RESULTS
In vitro, 4D PC MRI flow profiles showed the transition between laminar and turbulent flow with increasing velocities. In vivo, 4D PC MRI data of the ascending aorta and the pulmonary artery were confirmed by ultrasound, resulting in linear regressions of R (2) > 0.93. Magnitude- and direction-encoded streamlines differed substantially pre- and post-TAC surgery.


CONCLUSIONS
4D PC MRI is a feasible tool for in vivo velocity measurements on high-field small-animal scanners. Similar to clinical measurement, this method provides a complete spatially and temporally resolved dataset of the murine cardiovascular blood flow and allows for three-dimensional flow pattern analysis.
Department of Clinical Radiology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A16, 48149, Münster, Germany.
Philipp Rene
PR
Bovenkamp
Tobias
T
Brix
Florian
F
Lindemann
Richard
R
Holtmeier
Desiree
D
Abdurrachim
Michael T
MT
Kuhlmann
Gustav J
GJ
Strijkers
Jörg
J
Stypmann
Klaus H
KH
Hinrichs
Verena
V
Hoerr
D000818:Animals; D001011:Aorta; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001783:Blood Flow Velocity / Q000502:physiology*; D004195:Disease Models, Animal; D005240:Feasibility Studies; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D019047:Phantoms, Imaging; D014463:Ultrasonography