Helical structure of the cardiac ventricular anatomy assessed by diffusion tensor magnetic resonance imaging with multiresolution tractography.
OBJECTIVE
Deeper understanding of the myocardial structure linking the morphology and function of the heart would unravel crucial knowledge for medical and surgical clinical procedures and studies. Several conceptual models of myocardial fiber organization have been proposed but the lack of an automatic and objective methodology prevented an agreement. We sought to deepen this knowledge through advanced computer graphical representations of the myocardial fiber architecture by diffusion tensor magnetic resonance imaging.


METHODS
We performed automatic tractography reconstruction of unsegmented diffusion tensor magnetic resonance imaging datasets of canine heart from the public database of the Johns Hopkins University. Full-scale tractographies have been built with 200 seeds and are composed by streamlines computed on the vector field of primary eigenvectors at the diffusion tensor volumes. We also introduced a novel multiscale visualization technique in order to obtain a simplified tractography. This methodology retains the main geometric features of the fiber tracts, making it easier to decipher the main properties of the architectural organization of the heart.


RESULTS
Output analysis of our tractographic representations showed exact correlation with low-level details of myocardial architecture, but also with the more abstract conceptualization of a continuous helical ventricular myocardial fiber array.


CONCLUSIONS
Objective analysis of myocardial architecture by an automated method, including the entire myocardium and using several 3-dimensional levels of complexity, reveals a continuous helical myocardial fiber arrangement of both right and left ventricles, supporting the anatomical model of the helical ventricular myocardial band described by F. Torrent-Guasp.
Departamento de Ciencias de la Computación, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
Ferran
F
Poveda
Departamento de Ciencias de la Computación, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain; Centro de Visión por Computador, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
Debora
D
Gil
Departamento de Ciencias de la Computación, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
Enric
E
Martí
Centro de Visión por Computador, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
Albert
A
Andaluz
Departamento de Medicina, Universitat de Lleida, Lleida, Spain.
Manel
M
Ballester
Unidad de Imagen Cardiaca, Hospital de la Santa Creu i Sant Pau, IIB Sant Pau, Barcelona, Spain. Electronic address: fcarreras@santpau.cat.
Francesc
F
Carreras
D000818:Animals; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D004285:Dogs; D006321:Heart / Q000033:anatomy & histology*; D006352:Heart Ventricles / Q000033:anatomy & histology* / Q000648:ultrastructure; D021621:Imaging, Three-Dimensional; D023421:Models, Animal; D009206:Myocardium / Q000648:ultrastructure; D012680:Sensitivity and Specificity; D013552:Swine
Banda ventricular de miocardio; Corazón; Corazón helicoidal; DT-MRI; Diffusion magnetic resonance imaging; Diffusion tractography; HVMB; Heart; Helical heart; Myocardial ventricular band; Resonancia magnética de difusión; Tractografía de difusión; diffusion tensor magnetic resonance imaging; helical ventricular myocardial band