Concepts for visualization of multidirectional phase-contrast MRI of the heart and large thoracic vessels.
OBJECTIVE
Multidirectional phase-contrast magnetic resonance imaging allows the acquisition of time-resolved velocity fields (vectors) of cardiac and vascular blood flow. Its unique ability to provide vectorial flow information promises to give new insights into hemodynamic physiology. However, up to now appropriate and standardized procedures and software tools are missing to take advantage of all the information contained in the data. The objective of this work is to present a new versatile software tool and to demonstrate its practical value for the examination of multidirectional blood flow.


METHODS
An exemplary selection of data sets from healthy volunteers, patients with cardiovascular pathologies, and healthy domestic pigs has been acquired using a phase-contrast magnetic resonance imaging sequence based on FLASH (fast low angle shot) that encodes velocity as field of three-dimensional vectors. For data processing, we have developed a software tool that integrates the whole workflow, including noise filtering, interactive visualization, and flow quantification.


RESULTS
Using the software tool visualization of complex flow data is easily generated within 5 minutes; interactive exploration of the data is possible in real-time. Exemplary physiologic and pathologic flow patterns were visualized in an intuitive manner. The visual results suggest valuable diagnostic information; its significance, however, must be further evaluated together with the development of more specific data processing.


CONCLUSIONS
Multidirectional phase-contrast magnetic resonance imaging is a valuable tool for assessment of cardiac and vascular hemodynamics. With the development of tools that offer standardized and thus comparable visualizations it may be integrated into the clinical routine in the near future.
Unterhinninghofen
Roland
R
Institute of Computer Science and Engineering, University of Karlsruhe, Haid-und-Neu-Str. 7, 76131, Karlsruhe, Germany. roland.unterhinninghofen@ira.uka.de
Ley
Sebastian
S
Ley-Zaporozhan
Julia
J
von Tengg-Kobligk
Hendrik
H
Bock
Michael
M
Kauczor
Hans-Ulrich
HU
Szabó
Gábor
G
Dillmann
Rüdiger
R
D000328:Adult; D000465:Algorithms; D000818:Animals; D001013:Aorta, Thoracic / Q000502:physiology*; D016477:Artifacts; D001783:Blood Flow Velocity / Q000502:physiology; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology; D018618:Echocardiography, Doppler, Color / Q000379:methods; D006321:Heart / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D023421:Models, Animal; D011673:Pulsatile Flow / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D012984:Software; D013552:Swine
D003287:Contrast Media