Figure 5From: Comparison of diffusion tensor imaging by cardiovascular magnetic resonance and gadolinium enhanced 3D image intensity approaches to investigation of structural anisotropy in explanted rat hearts Visualization of the FLASH laminar architecture in a left ventricle septal ROI. A - The ROI is viewed so that the endocardial trabeculation is seen (black arrowheads); this trabeculation is continuous with the ventricular laminar architecture. In a small region of the myocardium the laminae have been segmented using an intensity threshold contour, and the 3D contour is colored green. B – the structure of these segmented contours are shown in the same orientation as in (A) and the ST (blue) and DTI (purple) putative sheetlet-normal vector orientations (e 3 DTI and v 3 ST) are shown on the sheetlet interstices. The size of a DTI voxel (200 μm isotropic) is shown. C – the cardiac location of the septal ROI. D – a view from the cardiac base onto the segmented laminae is shown, with the ST sheetlet normal vectors (blue). E – likewise, with the DTI sheetlet normal vectors (purple). DTI: Scan #1, 6-direction, b = 1000 s/mm2; ST: Scan #8; DTW = 3, STW = 3. R: right; L: left; endo: endocardium; FLASH: fast low angle shot; ST: structure tensor of FLASH data; DTI: diffusion tensor magnetic resonance imaging; DTW: derivative template width STW: smoothing template width. The symbols for vectors and derived angles are defined in Table 2.Back to article page