Mathematical models of left ventricular (LV) wall mechanics show that fiber stress depends heavily on the choice of muscle fiber orientation in the wall. This finding brought us to the hypothesis that fiber orientation may be such that mechanical load in the wall is homogeneous. Aim of this study was to use the hypothesis to compute a distribution of fiber orientation within the wall. In a fini...

PURPOSE This article presents a simple method for estimating the effective diffusion coefficients parallel and perpendicular to the axons unconfounded by the intravoxel fiber orientation distribution. We also call these parameters the per-axon or microscopic diffusion coefficients. THEORY AND METHODS Diffusion MR imaging is used to probe the underlying tissue material. The key observation is ...

The atrial pacemaker complex is responsible for the initiation and early propagation of cardiac impulses. Optical coherence tomography (OCT), a nondestructive imaging modality with spatial resolutions of ∼1 to 15 μm, can be used to identify unique fiber orientation patterns in this region of the heart. Functionally characterized canine sinoatrial nodes (SAN) (n=7) were imaged using OCT up to ∼1...

The present paper offers a meso-scale numerical model to investigate the effects of random distribution of aggregate particles and steel fibers on the elastic modulus of Steel Fiber Reinforced Concrete (SFRC). Meso-scale model distinctively models coarse aggregate, cementitious mortar, and Interfacial Transition Zone (ITZ) between aggregate, mortar, and steel fibers with their respective materi...

Research of the human brain connectome requires multiscale approaches derived from independent imaging methods ideally applied to the same object. Hence, comprehensible strategies for data integration across modalities and across scales are essential. We have successfully established a concept to bridge the spatial scales from microscopic fiber orientation measurements based on 3D-Polarized Lig...

We propose a deterministic and a probabilistic extension of classical diffusion tensor imaging (DTI) tractography algorithms based on a sharp fiber orientation distribution function (ODF) reconstruction from Q-Ball Imaging (QBI). An important contribution of the paper is the integration of some of the latest state-of-the-art high angular resolution diffusion imaging (HARDI) data processing meth...

Direct measurement of strain within muscle is important for understanding muscle 8 function in health and disease. Current technology (kinematics, dynamometry, electromyography) 9 provides limited ability to measure strain within muscle. Regional fiber orientation and length are 10 related with active/passive strain within muscle. Currently, ultrasound imaging provides the only 11 non-invasive ...

Difficulty in visualizing the intricate architecture of the tongue has limited our understanding of its function during speech, mastication, and swallowing, as well as its adaptation to surgical procedures. Tractography visualization using diffusion tensor imaging (DTI), a semiautomatic technique, can detect and display the spatial distribution of the muscle fiber bundle orientations as three-d...