Time-resolved 3-dimensional velocity mapping in the thoracic aorta: visualization of 3-directional blood flow patterns in healthy volunteers and patients.
OBJECTIVE
An analysis of thoracic aortic blood flow in normal subjects and patients with aortic pathologic findings is presented. Various visualization tools were used to analyze blood flow patterns within a single 3-component velocity volumetric acquisition of the entire thoracic aorta


METHODS
Time-resolved, 3-dimensional phase-contrast magnetic resonance imaging (3D CINE PC MRI) was employed to obtain complete spatial and temporal coverage of the entire thoracic aorta combined with spatially registered 3-directional pulsatile blood flow velocities. Three-dimensional visualization tools, including time-resolved velocity vector fields reformatted to arbitrary 2-dimensional cut planes, 3D streamlines, and time-resolved 3D particle traces, were applied in a study with 10 normal volunteers. Results from 4 patient examinations with similar scan prescriptions to those of the volunteer scans are presented to illustrate flow features associated with common pathologic findings in the thoracic aorta.


RESULTS
Previously reported blood flow patterns in the thoracic aorta, including right-handed helical outflow, late systolic retrograde flow, and accelerated passage through the aortic valve plane, were visualized in all volunteers. The effects of thoracic aortic disease on spatial and temporal blood flow patterns are illustrated in clinical cases, including ascending aortic aneurysms, aortic regurgitation, and aortic dissection.


CONCLUSIONS
Time-resolved 3D velocity mapping was successfully applied in a study of 10 healthy volunteers and 4 patients with documented aortic pathologic findings and has proven to be a reliable tool for analysis and visualization of normal characteristic as well as pathologic flow features within the entire thoracic aorta.
Markl
Michael
M
Department of Radiology, Stanford University, Stanford, CA 94304, USA. markl@s-word.stanford.edu
Draney
Mary T
MT
Hope
Michael D
MD
Levin
Jonathan M
JM
Chan
Frandics P
FP
Alley
Marcus T
MT
Pelc
Norbert J
NJ
Herfkens
Robert J
RJ
D000328:Adult; D000784:Aortic Dissection / Q000503:physiopathology; D001013:Aorta, Thoracic / Q000503:physiopathology*; D017545:Aortic Aneurysm, Thoracic / Q000503:physiopathology; D001018:Aortic Diseases / Q000503:physiopathology*; D001021:Aortic Valve / Q000503:physiopathology; D001022:Aortic Valve Insufficiency / Q000503:physiopathology; D001783:Blood Flow Velocity / Q000502:physiology; D003287:Contrast Media; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D011673:Pulsatile Flow / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D015203:Reproducibility of Results; D013997:Time Factors
D003287:Contrast Media