- Dissect any soft tissue from the specimen using forceps, being careful not to damage the specimen.
- Place sample in 70% ethanol, PBS, or 10% formalin. We prefer 70% ethanol as a fixative. If femurs will be tested mechanically after scanning use PBS. Specimens will not be accepted without an appropriate NFPA chemical hazard label on the container.
- Before samples can be scanned, a sample name must be generated for each sample in the Micro-CT database. Please ID all samples for scanning before submission.
The main bone parameters returned from the analysis are:
- TV: total volume [mm^3]
- BV: bone volume [mm^3]
- BV/TV: the relative volume of calcified tissue in the selected volume of interest (VOI)
- Tb.Th: measures the thickness of the trabecular structure
- Tb.N: indicates the number of trabeculae
- Tb.Sp: trabecular separation; measurement of the thickness of the spaces between the trabeculae. It is inversely proportional to the trabecular thickness
- Conn.D: connectivity density, 3-D connectivity index; measure of the degree to which a structure is multiply connected
- SMI: structure model index; this measurement is related to the architecture of the structure and ranges between 0 and 3. An SMI of 0 signifies that the structure is only plates, whereas a value of 3 means only cylindrical rods.
Parameters returned from analysis include:
- Vox-TV: Total fat volume [mm^3]
- Vox-BV: Visceral fat volume [mm^3]
- Tri-TV: Total volume of examined mouse part [mm^3]
- Mean 1: Mean density of visceral fat [mg HA/ccm]
- Mean 2: Mean density of subcutaneous fat [mg HA/ccm]Mean 3: Mean density of total fat [mg HA/ccm]
We analyzed repeatability, which is the variation in measurements obtained by one person on the microCT using multiple readings/quantification of the same samples. Four femora were scanned three times each and VOX-TV and VOX-BV were measured for each scan for trabecular and cortical regions. Deviations are represented for individual bone measurements and the calculations of group averages over the three repeat scans.
|Individual Bones, trabecular measurements||VOX-TV||VOX-BV|
|standard deviation as % of mean||Average 1.8% range from 0.08% to 4.4%||Average 5.5%, range from 0.6% to 8.4%|
|Individual Bones, cortical measurements||VOX-TV||VOX-BV|
|standard deviation as % of mean||Average 0.15% range from 0.06% to 0.3%||Average 0.3%, range from 0.07% to 0.5%|
|Experimental Group, n=4, trabecular measurements||VOX-TV||VOX-BV|
|standard deviation of group as % of group mean||1.89%||2.5%|
|Experimental Group, n=4, cortical measurements||VOX-TV||VOX-BV|
|standard deviation of group as % of group mean||0.05%||0.14%|
Estimates of cost can be provided after submission of the microCT servcie form if requested. The final cost is based on total scanning and analysis time as follows:
|Service||Internal Rate||IDeA-funded investigator
|Ex vivo specimens||$35.00/hour USD||$65.00/hour USD||$85.00/hour USD||Contact us for pricing|
|In vivo scanning||$65.00/hour USD||n/a||n/a||n/a|