Photoacoustic microscopy of myocardial sheet architecture in unfixed and unstained mammalian hearts
The laminar myocardial sheet architecture and its dynamic change play a key role in myocardial wall thickening. Histology, confocal optical microscopy (COM), and diffusion tensor MRI (DTI) have been used to unveil the structures and functions of the myocardial sheets. However, histology and COM require fixation, sectioning, and staining processes, which dehydrate and deform the sheet architecture. Although DTI can delineate sheet architecture nondestructively in viable hearts, it cannot provide cellular-level resolution. Here we show that photoacoustic microscopy (PAM), with high resolution (~1 μm) and label-free detection, is appropriate for imaging 3D myocardial architecture. Perfused half-split mouse hearts were also imaged by PAM in vitro without fixation, dehydration, nor staining. The laminar myocardial sheet architecture was clearly visualized within a 0.15 mm depth range. Two populations of oppositely signed sheet angles were observed. Therefore, PAM promises to access dynamic changes of myocardial architectures in ex vivo perfused-viable hearts.
Additional Information© 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). This work was sponsored in part by National Institutes of Health grants R01 EB000712, R01 EB008085, R01 CA134539, U54 CA136398, R01 CA157277, and 5P60 DK02057933. L.W. has a financial interest in Microphotoacoustics, Inc. and Endra, Inc., which, however, did not support this work.
Published - 82232G.pdf