The development and validation of micro‐CT of large deep frozen specimens. Issue 1 (30th December 2014)

• Record Type: Journal Article
• Authors: Kampschulte, Marian; Erdmann, Georg; Sender, Jonas; Martels, Gunhild; Böcker, Wolfgang; ElKhassawna, Thaqif; Heiß, Christian; Langheinrich, Alexanders Claus; Roeb, Elke; Roderfeld, Martin; Krombach, Gabriele Anja
• Is Part Of: Scanning. Volume 37:Issue 1(2015:Jan./Feb.)
• Page Start: 63
• Page End: 72
• Publication Date: 2014-12-30
• Subjects: Scanning electron microscopy -- Periodicals; 502.825
• DOI: 10.1002/sca.21180
• Languages: English
• ISSNs: 0161-0457

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Summary</title> <sec id="sca21180-sec-0001" sec-type="section"> <p>Repetitive freeze/thaw cycles lead to a progressive loss of structural and molecular integrity in deep frozen specimens. The aim of this study was to evaluate a micro‐CT stage, which maintains the cryoconservation of large specimens throughout micro‐CT imaging. Deep frozen ovine vertebral segments (−20 °C) were fixed in a micro‐CT stage made of expanded polystyrene and cooled with dry ice (0 g, 60 g and 120 g). The temperature inside the stage was measured half‐hourly over a time span of three hours with subsequent measurement of surface temperature. The method was validated in a series of 30 deep frozen vertebral specimens and in liver tissue after repetitive micro‐CT scanning. Isolation without cooling resulted in defrosting. Cooling with 60 g of dry ice led to a temperature rise inside the stage (max. 5.1 °C) and on the specimen surfaces (max. −3 °C). Cooling with 120 g of dry ice resulted in a significant (p < 0.001) and sufficient lowering of the temperature inside the stage (max. −14 °C) and on the surface of the specimens (max. −13.9 °C). The surface temperature during the subsequent micro‐CT validation study did not exceed −16 °C (processing time 1 h 45 min). The resolution was 33 μm isotropic voxel side length, enabling a binarization of bone microstructures. Temperature can reliably be maintained below −10 °C during a micro‐CT scan by applying the described technique. The resulting spatial resolution and image quality permits a binarization of bone microstructure. SCANNING 37:63–72, 2015. © 2014 Wiley Periodicals, Inc.</p> </sec> </abstract>