Research described in this paper was performed at the BMIT facility at the Canadian Light Source, which is supported by the Canada Foundation for Innovation, Natural Sciences and Engineering Research Council of Canada, the University of Saskatchewan, the Government of Saskatchewan, Western Economic Diversification Canada, the National Research Council Canada, and the Canadian Institutes of Health Research. The authors would like to thank the beamline scientists at the Canadian Light Source, particularly Adam Webb, Denise Miller, Sergey Gasilov, and Ning Zu for the assistance in set-up and troubleshooting of the SkyScan SR&#181;CT and white beam microscope systems. We also wish to thank Beth Dalzell from The University of Toledo College of Medicine and Life Sciences and Dr. Jeffrey Wenstrup of the Northeast Ohio Medical University for access to cadaveric samples for this study. JM Andronowski is supported through start-up research funds provided by The University of Akron and a National&#160;Institute of Justice Research and&#160;Development in Forensic Science&#160;for Criminal Justice Purposes grant (2018-DU-BX-0188).&#160;RA Davis is supported by a graduate assistantship provided by The University of Akron. Equipment and supplies used for coring and sawing were purchased by start-up funds provided by The University of Akron and NSF grant EAR-1624242 to CW Holyoke.

All specimens were sourced from embalmed cadaveric donors at the University of Toledo, College of Medicine and Life Sciences and Northeast Ohio Medical University (NEOMED), with the informed consent of the donor themselves or the donor&#39;s next-of-kin. The University of Akron Institutional Review Board for the Protection of Human Subjects (IRB) deemed these specimens exempt from full IRB review as they were not procured from living individuals. Demographic information including age, sex, and cause of death were availab...

<ol>
	<li>Andronowski, J. M., Crowder, C., Soto Martinez, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advancements+in+the+analysis+of+bone+microstructure:+New+dimensions+in+forensic+anthropology.">Recent advancements in the analysis of bone microstructure: New dimensions in forensic anthropology.</a> Forensic Sciences Research. 3 (4), 278-293 (2018).</li><li>Wysokinski, T. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Beamlines+of+the+biomedical+imaging+and+therapy+facility+at+the+Canadian+light+source+-+part+3.">Beamlines of the biomedical imaging and therapy facility at the Canadian light source - part 3.</a> Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 775, 1-4 (2015).</li><li>Carter, Y., Suchorab, J. L., Thomas, C. D. L., Clement, J. G., Cooper, D. M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Normal+variation+in+cortical+osteocyte+lacunar+parameters+in+healthy+young+males.">Normal variation in cortical osteocyte lacunar parameters in healthy young males.</a> Journal of Anatomy. 225 (3), 328-336 (2014).</li><li>Carter, Y., Thomas, C. D. L., Clement, J. G., Cooper, D. M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Femoral+osteocyte+lacunar+density,+volume+and+morphology+in+women+across+the+lifespan.">Femoral osteocyte lacunar density, volume and morphology in women across the lifespan.</a> Journal of Structural Biology. 183 (3), 519-526 (2013).</li><li>Langer, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=X-Ray+Phase+Nanotomography+Resolves+the+3D+Human+Bone+Ultrastructure.">X-Ray Phase Nanotomography Resolves the 3D Human Bone Ultrastructure.</a> PLoS ONE. 7 (8), 35691 (2012).</li><li>Peyrin, F., Dong, P., Pacureanu, A., Langer, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micro-+and+Nano-CT+for+the+Study+of+Bone+Ultrastructure.">Micro- and Nano-CT for the Study of Bone Ultrastructure.</a> Current Osteoporosis Reports. 12 (4), 465-474 (2014).</li><li>Dong, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+osteocyte+lacunar+morphometric+properties+and+distributions+in+human+femoral+cortical+bone+using+synchrotron+radiation+micro-CT+images.">3D osteocyte lacunar morphometric properties and distributions in human femoral cortical bone using synchrotron radiation micro-CT images.</a> Bone. 60, 172-185 (2014).</li><li>Gauthier, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+micro+structural+analysis+of+human+cortical+bone+in+paired+femoral+diaphysis,+femoral+neck+and+radial+diaphysis.">3D micro structural analysis of human cortical bone in paired femoral diaphysis, femoral neck and radial diaphysis.</a> Journal of Structural Biology. 204 (2), 182-190 (2018).</li><li>Giuliani, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bisphosphonate-related+osteonecrosis+of+the+human+jaw:+A+combined+3D+assessment+of+bone+descriptors+by+histology+and+synchrotron+radiation-based+microtomography.">Bisphosphonate-related osteonecrosis of the human jaw: A combined 3D assessment of bone descriptors by histology and synchrotron radiation-based microtomography.</a> Oral Oncology. 82, 200-202 (2018).</li><li>Andronowski, J. M., Pratt, I. V., Cooper, D. M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Occurrence+of+osteon+banding+in+adult+human+cortical+bone.">Occurrence of osteon banding in adult human cortical bone.</a> American Journal of Physical Anthropology. 164 (3), 635-642 (2017).</li><li>Andronowski, J. M., Mundorff, A. Z., Pratt, I. V., Davoren, J. M., Cooper, D. M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluating+differential+nuclear+DNA+yield+rates+and+osteocyte+numbers+among+human+bone+tissue+types:+A+synchrotron+radiation+micro-CT+approach.">Evaluating differential nuclear DNA yield rates and osteocyte numbers among human bone tissue types: A synchrotron radiation micro-CT approach.</a> Forensic Science International: Genetics. 28, 211-218 (2017).</li><li>Britz, H. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prolonged+unloading+in+growing+rats+reduces+cortical+osteocyte+lacunar+density+and+volume+in+the+distal+tibia.">Prolonged unloading in growing rats reduces cortical osteocyte lacunar density and volume in the distal tibia.</a> Bone. 51 (5), 913-919 (2012).</li><li>Maggiano, I. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+reconstruction+of+Haversian+systems+in+human+cortical+bone+using+synchrotron+radiation-based+micro-CT:+morphology+and+quantification+of+branching+and+transverse+connections+across+age.">Three-dimensional reconstruction of Haversian systems in human cortical bone using synchrotron radiation-based micro-CT: morphology and quantification of branching and transverse connections across age.</a> Journal of Anatomy. 228 (5), 719-732 (2016).</li><li>Cooper, D. M. L., Thomas, C. D. L., Clement, J. G., Hallgr&#237;msson, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+microcomputed+tomography+imaging+of+basic+multicellular+unit-related+resorption+spaces+in+human+cortical+bone.">Three-dimensional microcomputed tomography imaging of basic multicellular unit-related resorption spaces in human cortical bone.</a> The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology. 228 (7), 806-816 (2006).</li><li>Holyoke, C. W., Kronenberg, A. K., Newman, J., Ulrich, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rheology+of+magnesite:+Rheology+of+Magnesite.">Rheology of magnesite: Rheology of Magnesite.</a> Journal of Geophysical Research: Solid Earth. 119 (8), 6534-6557 (2014).</li><li>Holyoke, C. W., Kronenberg, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversible+water+weakening+of+quartz.">Reversible water weakening of quartz.</a> Earth and Planetary Science Letters. 374, 185-190 (2013).</li><li>Holyoke, C. W., Kronenberg, A. K., Newman, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dislocation+creep+of+polycrystalline+dolomite.">Dislocation creep of polycrystalline dolomite.</a> Tectonophysics. 590, 72-82 (2013).</li><li>Raterron, P., Fraysse, G., Girard, J., Holyoke, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strength+of+orthoenstatite+single+crystals+at+mantle+pressure+and+temperature+and+comparison+with+olivine.">Strength of orthoenstatite single crystals at mantle pressure and temperature and comparison with olivine.</a> Earth and Planetary Science Letters. 450, 326-336 (2016).</li><li>Millard, J. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pressure+Dependence+of+Magnesite+Creep.">Pressure Dependence of Magnesite Creep.</a> Geosciences. 9 (10), 420 (2019).</li><li>Thomas, C. D. L., Feik, S. A., Clement, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regional+variation+of+intracortical+porosity+in+the+midshaft+of+the+human+femur:+age+and+sex+differences.">Regional variation of intracortical porosity in the midshaft of the human femur: age and sex differences.</a> Journal of Anatomy. 206 (2), 115-125 (2005).</li><li>Jowsey, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age+Changes+in+Human+Bone.">Age Changes in Human Bone.</a> Clinical Orthopaedics and Related Research. 17, 210 (1960).</li><li>Martin, R. B., Pickett, J. C., Zinaich, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+of+skeletal+remodeling+in+aging+men.">Studies of skeletal remodeling in aging men.</a> Clinical Orthopaedics and Related Research. (149), 268-282 (1980).</li><li>Martin, R. B., Burr, D. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+implications+of+porosity+distribution+in+bone+of+the+appendicular+skeleton.">Mechanical implications of porosity distribution in bone of the appendicular skeleton.</a> Orthopedic Transactions. 8, 342-343 (1984).</li><li>Bousson, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distribution+of+Intracortical+Porosity+in+Human+Midfemoral+Cortex+by+Age+and+Gender.">Distribution of Intracortical Porosity in Human Midfemoral Cortex by Age and Gender.</a> Journal of Bone and Mineral Research. 16 (7), 1308-1317 (2001).</li><li>Goldman, H. M., Thomas, C. D. L., Clement, J. G., Bromage, T. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relationships+among+microstructural+properties+of+bone+at+the+human+midshaft+femur.">Relationships among microstructural properties of bone at the human midshaft femur.</a> Journal of Anatomy. 206 (2), 127-139 (2005).</li><li>De Micheli, P. O., Witzel, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microstructural+mechanical+study+of+a+transverse+osteon+under+compressive+loading:+The+role+of+fiber+reinforcement+and+explanation+of+some+geometrical+and+mechanical+microscopic+properties.">Microstructural mechanical study of a transverse osteon under compressive loading: The role of fiber reinforcement and explanation of some geometrical and mechanical microscopic properties.</a> Journal of Biomechanics. 44 (8), 1588-1592 (2011).</li><li>Martin, R. B., Boardman, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+collagen+fiber+orientation,+porosity,+density,+and+mineralization+on+bovine+cortical+bone+bending+properties.">The effects of collagen fiber orientation, porosity, density, and mineralization on bovine cortical bone bending properties.</a> Journal of Biomechanics. 26 (9), 1047-1054 (1993).</li><li>Cooper, D. M. L., Turinsky, A. L., Sensen, C. W., Hallgr&#237;msson, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+3D+analysis+of+the+canal+network+in+cortical+bone+by+micro-computed+tomography.">Quantitative 3D analysis of the canal network in cortical bone by micro-computed tomography.</a> The Anatomical Record Part B: The New Anatomist. 274 (1), 169-179 (2003).</li><li>Crowder, C., Heinrich, J., Stout, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rib+histomorphometry+for+adult+age+estimation.">Rib histomorphometry for adult age estimation.</a> Forensic Microscopy for Skeletal Tissues: Methods and Protocols. , 109-127 (2012).</li><li>Pfeiffer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Paleohistology:+Health+and+disease.">Paleohistology: Health and disease.</a> Biological Anthropology of the Human Skeleton. , 287-302 (2000).</li><li>Bone Hedges, R. E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=diagenesis:+an+overview+of+processes.">diagenesis: an overview of processes.</a> Archaeometry. 44 (3), 319-328 (2002).</li><li>. The use of formaldehyde imbedded human remains in experimental procedures Available from: <a target="_blank" href="https://capa-acap.net/sites/default/files/basic-page/capa_2017_program_final_no_cover.pdf">https://capa-acap.net/sites/default/files/basic-page/capa_2017_program_final_no_cover.pdf</a> (2017)</li><li>Currey, J. D., Brear, K., Zioupos, P., Reilly, G. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+formaldehyde+fixation+on+some+mechanical+properties+of+bovine+bone.">Effect of formaldehyde fixation on some mechanical properties of bovine bone.</a> Biomaterials. 16 (16), 1267-1271 (1995).</li><li>Asaka, T., Kikugawa, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+formaldehyde+solution+on+fracture+characteristics+of+bovine+femoral+compact+bone.">Effect of formaldehyde solution on fracture characteristics of bovine femoral compact bone.</a> Journal of the Japan Institute of Metals. 69 (8), 711-714 (2005).</li></ol>

There has been no comprehensive, standardized protocol for procuring uniform and cylindrical cortical bone core samples for high-resolution SR&#181;CT imaging with limited FOV setups. The protocol detailed here fills&#160;that void by providing a comprehensive tutorial regarding how to procure consistently sized cortical bone core samples for SR&#181;CT imaging and the subsequent accurate visualization and extraction of microarchitectural data. We have shown that our protocol provides a more standardized and reliable met...

With recent advancements in imaging technology, it is now feasible to acquire X-ray imaging data with very high resolution. Desktop micro-CT (&#181;CT) systems are the current standard for imaging cancellous bone due to their non-destructive nature1. When imaging microstructural features of cortical bone, however, &#181;CT use has been more limited. Due to resolution constraints, desktop systems cannot attain the resolution required to image microstructural features smaller than cortical pores, such as osteocyte lacunae. For this application, SR&#181;CT is ideal owing to the greater resolution of these systems1. For example, experiments at the Canadian Light Source (CLS) on the BioMedical Imaging and Therapy (BMIT) beamlines2 have produced images with voxels as small as 0.9 &#181;m. Previous studies1,3,4,5 have used this resolution to acquire projections and subsequent three-dimensional (3D) renders from cortical bone specimens from human long bones (Figure 1) to quantify osteocyte lacunar density4,6,7,8,9 and variation in the lacunar shape and size3 across the human lifespan and between the sexes. Further studies have demonstrated the presence of osteon banding in humans10, a phenomenon previously recognized to be associated with only nonhuman mammals in the forensic anthropological literature.
In order to achieve exceptional resolution, the X-ray beam must be finely focused within the field of view (FOV), which often limits the maximum specimen size to a few millimeters in diameter. Currently, there have been no comprehensive, standardized procedures described in the literature outlining bone sample procurement that meet these restrictions. Centering specimens within the FOV is critical to ensure that 1) the sample remains centered as it rotates 180&#176; during imaging, and 2) scan artifacts are limited since there is no image truncation. In other words, no portions of the sample outside of the FOV interfere with the beam entering its focal point inside the FOV. If this occurs, the reconstruction algorithm is deprived of some of the attenuation data needed for a fully correct reconstruction. It is further worth noting that 360&#176; (full rotation) scans minimize the effects of beam hardening but increase artifacts caused by misalignment and sample movement during imaging. Thus, while a 360&#176; scan will typically generate cleaner data, imaging time is doubled and so a compromise between experimental cost and data quality must be addressed.
An important and often overlooked aspect of bone imaging experiments is the accurate and replicable specimen preparation technique performed prior to scanning. Studies that incorporate SR&#181;CT methods into their experiments briefly mention their sampling protocol, but the authors provide little to no detail regarding the particular methodology used to gather their specimens. Many such studies mention cutting rectilinear bone blocks of arbitrary dimensions, but generally provide no further information about the tools or embedding materials used3,4,10,11,12,13,14. Some researchers commonly use handheld rotary tools (e.g., Dremel) to remove rectilinear blocks of bone from a region of interest (ROI)3,4,10,11,12,13,14. This method results in nonuniformly sized samples that may be larger than the FOV, increasing the likelihood of scan artifacts and image truncation. Such specimens often require further refining using a precision diamond-wafer saw (e.g., Buehler Isomet). Procuring samples with consistent dimensions (to the two-hundredths/mm) is critical to ensure that the acquired datasets are of the highest quality and the subsequent results are replicable.
The limited reporting of sample procurement methodology adds an extra layer of difficulty when attempting to employ and/or validate methods performed in a previous study. Currently, researchers must contact authors directly for further details on their sampling procedures. The protocol detailed here provides biomedical researchers with a thoroughly documented, replicable, and cost-efficient sampling technique. The primary objective of this article is to provide a comprehensive tutorial regarding how to procure consistently sized cortical bone core samples using a mill-drill press and diamond coring bit for the accurate visualization and extraction of microarchitectural data. This method is modified from procedures used to routinely collect uniform, small-diameter (1-5 mm) cylinders from blocks of hard materials in high pressure rock mechanics15,16,17,18,19.

<table border="0" cellpadding="0" cellspacing="0" style="width:1367px;" width="1367">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:215px;">1-1/8&#34; plunge cutting carbide for composites</td>
			<td style="width:120px;">Warrior</td>
			<td style="width:133px;">61812</td>
			<td style="width:899px;">28.6mm plunge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">70% Ethanol</td>
			<td style="width:120px;">Fisher Scientific</td>
			<td style="width:133px;">BP8201500</td>
			<td>3.8 Liters</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Blunt-tipped forceps</td>
			<td style="width:120px;">Fisher Scientific</td>
			<td style="width:133px;">10-300</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Centrifuge tubes</td>
			<td style="width:120px;">ThermoFisher</td>
			<td style="width:133px;">55398</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Crystalbond 509-3 Epoxy</td>
			<td style="width:120px;">Ted Pella</td>
			<td style="width:133px;">821-3</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">CTAnalyser</td>
			<td style="width:120px;">Bruker microCT</td>
			<td style="width:133px;">v.1.15.4.0</td>
			<td>Download and install at https://www.bruker.com/products/microtomography/micro-ct-software/3dsuite.html</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Dental Tool Kit</td>
			<td style="width:120px;">Amazon</td>
			<td style="width:133px;">787269885110</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:215px;">Diamond wafering saw blade for composite material</td>
			<td style="width:120px;">Buehler</td>
			<td style="width:133px;">#11-4247</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Drill Press</td>
			<td style="width:120px;">Jet Mill/Drill</td>
			<td style="width:133px;">350017</td>
			<td>Model: JMD-15, benchtop drill presses are suitable substites, but typically lack a translatable machine table for positioning samples beneath the drill stem</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Fine-tipped forceps</td>
			<td style="width:120px;">Fisher Scientific</td>
			<td style="width:133px;">22-327379</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:215px;">Fixturing clamps for XY machine table for mill/drill</td>
			<td style="width:120px;">MSC Industrial Supply</td>
			<td style="width:133px;">#04804571</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Glass microscope slides</td>
			<td style="width:120px;">Ted Pella</td>
			<td style="width:133px;">26005</td>
			<td>75x50mm slides, 1mm thick</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Glass slide chuck</td>
			<td style="width:120px;">Buehler</td>
			<td style="width:133px;">#112488</td>
			<td>Large enough to hold 75x50mm glass slides</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:215px;">Hot plate capable of reaching 140 &#176;C</td>
			<td style="width:120px;">ThermoScientific</td>
			<td style="width:133px;">HP88850105</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Incubator</td>
			<td style="width:120px;">NAPCO</td>
			<td>Model 4200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Isocut Fluid</td>
			<td style="width:120px;">Buehler</td>
			<td style="width:133px;">111193032</td>
			<td>Lubricant; 30mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Jeweler&#39;s diamond coring drill bit</td>
			<td style="width:120px;">Otto Frei</td>
			<td style="width:133px;">#119.050</td>
			<td>2mm inner diameter hollow stem coring bit</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">NRecon</td>
			<td style="width:120px;">Bruker microCT</td>
			<td style="width:133px;">v.1.6.10.2</td>
			<td>Download and install at https://www.bruker.com/products/microtomography.html</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Oscillating saw</td>
			<td style="width:120px;">Harbor Freight</td>
			<td style="width:133px;">62866</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Oven-safe glass dishes</td>
			<td style="width:120px;">Pyrex</td>
			<td style="width:133px;">1117715</td>
			<td>Glass food storage container</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:215px;">Precision slow-speed saw (Isomet 1000)</td>
			<td style="width:120px;">Buehler</td>
			<td style="width:133px;">111280160</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Razor blades</td>
			<td style="width:120px;">Amazon</td>
			<td style="width:133px;">25181</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Shallow aluminum tins</td>
			<td style="width:120px;">Amazon</td>
			<td style="width:133px;">B01MRWLD0R</td>
			<td>~8cm diameter</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:215px;">Specimen cups</td>
			<td style="width:120px;">Amazon</td>
			<td style="width:133px;">616784425436 885334344729</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Tergazyme detergent</td>
			<td style="width:120px;">Alconox</td>
			<td style="width:133px;">1304-1</td>
			<td>1.8kg box</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Ultrasonic cleaner</td>
			<td style="width:120px;">MTI Corporation</td>
			<td style="width:133px;">KJ201508006</td>
			<td></td>
		</tr>
	</tbody>
</table>

a sectioning, coring, and image processing guide for high-throughput cortical bone sample procurement and analysis for synchrotron micro-ct

Bone is a dynamic and mechanically active tissue that changes in structure over the human lifespan. The products of the bone remodeling process have been studied substantially using traditional two-dimensional techniques. Recent advancements in X-ray imaging technology via desktop micro-computed tomography (&#181;CT) and synchrotron radiation micro-computed tomography (SR&#181;CT) have allowed for the acquisition of high-resolution three-dimensional (3D) scans of a larger field of view (FOV) than other 3D imaging techniques (e.g., SEM) providing a more complete picture of microscopic structures within human cortical bone. The specimen should be accurately centered within the FOV, however, to limit the appearance of streak artifacts known to impact data analysis. Previous studies have reported procurement of irregularly shaped rectilinear bone blocks that result in imaging artifacts due to uneven edges or image truncation. We have applied a geological sampling protocol (coring) to procure consistently sized cortical bone core specimens for SR&#181;CT experiments from the anterior aspect of human femora. This coring method is efficient and minimally destructive to tissue. It creates uniform cylindrical samples that decrease imaging artifacts by nature of being isometric during rotation and providing a uniform path length for X-ray beams throughout scanning. Image processing of X-ray tomographic data of cored and irregularly shaped samples confirms the potential of the technique to improve visualization and analysis of cortical bone microarchitecture. A goal of this protocol is to deliver a reliable and repeatable method for the extraction of cortical bone cores that is adaptable for various types of high-resolution bone imaging experiments. An overarching goal of the work is to create a standardized cortical bone procurement for SR&#181;CT that is affordable, consistent, and straightforward. This procedure may further be adapted by researchers in related fields who commonly evaluate hard composite materials such as in biological anthropology, geosciences, or material sciences.

The described method of core sampling proved to be highly effective and efficient. Coring specimens using this protocol allowed for the procurement of &#62;300 consistently sized samples for experiments on the CLS BMIT-BM beamline2, with an FOV of ~2 mm at 1.49 &#181;m voxel size. To validate the consistency of core diameter, three measurements were taken along the length (top, middle, bottom) of a subset of human anterior femoral cores (n=69). The average diameter of the cores was 1.96 &...

Watch this Scientific Journal Video about A Sectioning, Coring, and Image Processing Guide for High-Throughput Cortical Bone Sample Procurement and Analysis for Synchrotron Micro-CT at JoVE.com

A Sectioning, Coring, and Image Processing Guide for High-Throughput Cortical Bone Sample Procurement and Analysis for Synchrotron Micro-CT

We employed a geological (coring) sampling protocol to procure cortical bone specimens of uniform size for SR&#181;CT experiments from the anterior aspect of human femora. This method is minimally destructive, efficient, results in cylindrical specimens that minimize imaging artifacts from irregular sample shapes and improves microarchitectural visualization and analysis.

Bone is a dynamic and mechanically active tissue that changes in structure over the human lifespan. The products of the bone remodeling process have been ...

Available data related to bone specimen procurement for synchrotron micro-computed tomography remain sparse. Our comprehensive tutorial provides a methodology that is straightforward, minimally destructive, and cost-effective. Procuring bone specimens with consistent dimensions and a cylindrical shape is critical to ensure that the resulting data sets are of the highest quality and the results are applicable.The techniques described in this manuscript are applicable to coring rocks, fossils, or any hard material. We've used these to collect uniformly sized cores of rocks and single crystals for high-pressure experiments to explore the rheology of Earth's crust and upper mantle. Novice corers may find that the bone specimen forms conical shapes.This can be addressed by allowing adequate and enough time for bone dust to flush from the drill bit and slowing down coring speed. There's a lack of instructional texts and videos that demonstrate bone specimen procurement for synchrotron micro-computed tomography and is the logical analysis. Our step-by-step bone preparation tutorial helps to fill this out gap.Place a 75 by 25 millimeter glass microscope slide on hot plates up to 140 degrees Celsius and melt a generous amount of thermal epoxy resin on the center of the slide. Press the inferior aspect of the bone block into the thermal epoxy resin on the microscope slide with the length of the bone perpendicular to the slide. Shift the sample back and forth in order to coat the underside of the bone and ensure secure adhesion.Let the mounted specimen rest on the hot plate for approximately five minutes to allow the thermal epoxy to wick into the pores and cracks making sure that the epoxy on the slide is free of bubbles. If bubbles are present, shift the sample back and forth to remove them. Use blunt forceps to remove the slide with the mounted specimen from the hot plate and allow it to cool at room temperature for about 10 minutes, then remove any epoxy from the edge of the slide with a razor blade to ensure that the chuck adequately grips the slide.Attach the slide with the adhered sample to a glass slide chuck and mount the chuck on the swivel arm of a slow speed sectioning saw positioning it so that a cross-section of the bone can be cut perpendicular to its length. Adjust the swivel arm to ensure that the blade contacts and transects the sample. Add weights to the far side of the cutting arm to counter the weight of the arm and add distilled water and cutting fluid to the fluid receptacle.Tightly secure the diamond wafer blade and ensure that the fluid level submerges the cutting portion of the blade. Set the speed to 200 RPM and slowly lower the sample onto the blade. Once the saw begins sectioning, ensure that the blade and chuck are not wobbling or bouncing.If they are, immediately stop the saw and tighten the blade or chuck arm assembly. If the chuck is aggressively moving up and down, add more counterweights. The first thick section is a waste cut that will provide a well-defined surface parallel to each additional cut.After the initial waste cut, raise the swivel arm and move the chuck five millimeters towards the blade using the positioning dial. After sectioning is complete, place the glass slide with the mounted specimen on a hot plate to melt the thermal epoxy. Mount five millimeter bone sections to the bottom of a shallow aluminum tin using the thermal epoxy bonding technique previously described.Place the tin on an XY machine table of the mill drill press and hand-tighten the fixturing clamps. Insert a two millimeter inner diameter hollow shaft jewelers diamond tipped coring drill bit into the mill drill chuck and adjust the depth limiter to prevent coring through the tin. Align the central anterior aspect of the bone sample beneath the drill bit while avoiding close contact with the periosteum and ostium or highly trabecularized areas.Fill the tin with distilled water to completely cover the sample which prevents heat buildup, burning of the sample, and damage to the drill bit during coring. The mill drill press can be dangerous if proper safety measures aren't taken. Operators should ensure that they wear safety glasses, that loose clothing is secured, and that long hair is pulled back so it doesn't get caught in the spindle.for the first few instances of contact between the core bit and bone, apply gentle pressure in order to wear a ring on the superior surface of the bone. This prevents deflection of the drill bit at the beginning of the coring process and ensures correct placement of the bit. During coring, lift the drill bit in and out of the sample while keeping the bit's tip beneath the water surface.Do this every few seconds to flush out trapped bone dust and ensure debris is not occluding the drill bit. After coring is complete, the resulting bone core may become lodged in the hollow stemmed drill bit. Use a pair of fine tipped forceps or a small Allen wrench to dislodge the core from the bit.Store the cored sample in a labeled microcentrifuge tube in a cool and dry location until imaging. The described method of core sampling proved to be highly effective and efficient. Representative figures comparing the image processing workflow of a cored sample and one procured using a rotary tool are shown here.The sample cut using the common rotary tool exhibited an increased number of canals and lacunae and a decreased average canal diameter, canal volume, and cortical porosity when compared to the cored sample. This table shows porosity data for each sample. Although the coring protocol decreases artifacts observed in synchrotron microcomputer tomography scans, the lower quality artifact-laden figures from the rectilinear bone block experiments represent a multifaceted issue.Subsequent image processing confirmed the potential of the technique to improve visualization of cortical bone micro architecture. For example, mineralization differences, improved delineation of osteonal boundaries, and consistent visualization of soft tissues within vascular canals were observed. Proceeding slowly is the key to getting consistently-sized cylindrical samples.Going too fast can cause the specimens to become cone-shaped instead of cylindrical. While procuring thick sections for coring, further thick sections can be gathered for Brightfield or confocal microscopy. This allows for the visualization of the canalicular network.

a-sectioning-coring-image-processing-guide-for-high-throughput

Research

JoVE Journal

Biology

5.0K vistas.  The University of Akron. Available data related to bone specimen procurement for synchrotron micro-computed tomography remain sparse. Our comprehensive tutorial provides a methodology that is straightforward, minimally destructive, and cost-effective. Procuring bone specimens with consistent dimensions and a cylindrical shape is critical to ensure that the resulting data sets are of the highest quality and the results are applicable.The techniques described in this manuscript are applicable to coring rocks, fo...