Virtual sectioning of cardiac tissue relative to fiber orientation.
Ventricular myocardium is composed of muscle fibers organised into a complex, branching, laminar (sheet-like) structure. The fibers run approximately parallel to the epicardial wall, but their orientation relative to the circumferential axis varies transmurally, rotating from around -70 degrees at the epicardium to +70 degrees at the endocardium. This ensures that any flat transmural imaging plane or histological section contains only a partial description of myocardial architecture, as fibers intersect with the image plane at a variety of angles depending on transmural depth. We have developed a new way of viewing microstructure that accounts for this variation. Extended-volume confocal 3-D images of normal rat left-ventricular wall have previously been acquired, with an approximate size of 4x1x1 mm3. The transmural fiber rotation is measured on planes parallel to the epicardium, and used to define a curvilinear coordinate system with a transmural axis, and a second axis defined relative to the local fiber orientation. Images extracted from the image volume on curvilinear planes derived from these axes reveal a consistent view of myocardial architecture.
Sands
Gregory B
GB
Bioengineering Institute, Department of Physiology, University of Auckland, Auckland, New Zealand. g.sands@auckland.ac.nz
Smaill
Bruce H
BH
LeGrice
Ian J
IJ
D000465:Algorithms; D019412:Anatomy, Cross-Sectional / Q000295:instrumentation* / Q000379:methods*; D000818:Animals; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D018613:Microscopy, Confocal / Q000295:instrumentation* / Q000379:methods*; D008867:Microtomy / Q000295:instrumentation* / Q000379:methods*; D009206:Myocardium / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000295:instrumentation / Q000379:methods