Cryostatic micro-computed tomography imaging of arterial wall perfusion.

A double-walled copper vessel, 32 cc in volume, was fabricated for scanning tissue specimens while maintained below freezing point. To keep specimen temperature within +/- 1 degrees C, temperature sensors within the chamber control, the rate of inflow of the cold nitrogen gas vented through the chamber. The specimen is attached to a small platform on top of a vertical pin which is attached to the computer-controlled rotating stage under the vessel.

Three-dimensional imaging of fractures in outlet struts of Björk-Shiley convexo-concave heart valves by microcomputed tomography in vitro.

Background And Aims Of The Study: For implanted Björk-Shiley convexo-concave (BSCC) heart valves, structural failure of the valve's U-shaped outlet strut results in embolization of its blood flow-regulating disc (occluder), with consequent patient morbidity and mortality. After a variable and unpredictable number of cardiac cycles, one strut leg may fatigue ('single-leg separation'; SLS); subsequently the other strut leg may also fatigue, resulting in full structural failure ('outlet strut failure'; OSF). Some BSCC valves are believed to be at more risk of SLS and OSF than others.