A method of removing retardance induced by scattering of collagenous fiber bundles

In this work, we report a method of removing scattering induced retardance in polarization sensitive full field optical coherence tomography (PS-FFOCT). First, the Mueller matrix that describes its operation is derived. The thickness invariant retardance induced by the scattering of collagenous fiber bundles is then used to find the accurate values of the birefringence of the layers that consist collagenous fibers. Finally, the initial en face birefringent images of in vitro beef tendon samples are presented to demonstrate the capability of our method.

Large Cysts of the Pineal Gland: Report of Two Cases

Two cases of large, nontumorous cysts of the pineal gland are reported, the histopathology of which was confirmed using surgically resected specimens. Both patients were middle-aged, and the pineal cysts were found incidentally. The histopathological findings in the two cases were strikingly similar to each other and were characterized by the following points: 1) the cyst wall typically consisted of three layers, namely, collagenous fibers, glia-like cells, and normal pineal cells; 2) the cyst wall was relatively thin, approximately 100 to 300 μm in thickness; and 3) deposits of caleification almost always existed on the side of the layer of collagenous fiber. Because these findings are clearly different from those previously reported. large benign cysts of the pineal gland. or at least some of them, may constitute a new pathological entity. It is important to consider this possible pathological diagnosis when dealing with pineal cysts. (Neurosurgery 29:101-106, 1991)