MicroCT examination of human bone specimens

Effects of polymethylmethacrylate embedding on structural parameters

E. Perilli, F. Baruffaldi, M. Visentin, B. Bordini, F. Traina, A. Cappello, M. Viceconti

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

X-ray microtomography permits the nondestructive investigation of trabecular and cortical bone specimens without special preparation of the sample. To do a quantitative characterization, the cross-section images have to be binarized, separating bone from nonbone. For this purpose, a widely used method is uniform thresholding. However, for commonly available microtomography scanners which use a polychromatic X-ray source, it is unclear what effect the surrounding medium (e.g. air, saline solution, polymethylmethacrylate) has on the threshold value used for the binarization. In the literature an easy procedure to find the optimal uniform threshold value for a given acquisition condition is reported. By applying this procedure, the present work investigated whether a microtomography scan of trabecular bone samples in air or embedded in polymethylmethacrylate gave the same results in terms of structural parameters. The gold standard, that is, histological sections, was used as a reference. Two fixed threshold values were found, one for the microtomography scans performed in air and one for the scans with the same samples embedded in polymethylmethacrylate. These were applied on the correspondent microtomography images for the estimation of structural parameters, such as bone volume fraction, direct trabecular thickness, direct trabecular separation and structure model index. Paired comparisons were made in bone volume fraction between histological sections and microtomography cross-sections for the same bone samples scanned first in air and then embedded in polymethylmethacrylate, by which no significant differences were found. Paired comparisons were also made in bone volume fraction, direct trabecular thickness, direct trabecular separation and structure model index for the same samples over volumes of interest of 4 × 4 × 4 mm3 between microtomography scans in air and scans with the samples embedded in polymethylmethacrylate. Neither these comparisons showed significant differences. This leads to the conclusion that structural parameters estimated by microtomography for human trabecular bone samples scanned either in air or embedded in polymethylmethacrylate are not affected by the surrounding medium (i.e. presence or absence of polymethylmethacrylate), provided that the corresponding optimal threshold value is applied for each acquisition condition.

Original languageEnglish
Pages (from-to)192-200
Number of pages9
JournalJournal of Microscopy
Volume225
Issue number2
DOIs
Publication statusPublished - Feb 2007

Fingerprint

X-Ray Microtomography
Polymethyl Methacrylate
embedding
bones
Bone
examination
Bone and Bones
Air
air
Matched-Pair Analysis
Volume fraction
thresholds
Model structures
acquisition
X rays
cross sections
Sodium Chloride
scanners
X-Rays
x rays

Keywords

  • Bone stereology
  • Embedding
  • MicroCT
  • Polymethylmethacrylate
  • Thresholding

ASJC Scopus subject areas

  • Instrumentation

Cite this

MicroCT examination of human bone specimens : Effects of polymethylmethacrylate embedding on structural parameters. / Perilli, E.; Baruffaldi, F.; Visentin, M.; Bordini, B.; Traina, F.; Cappello, A.; Viceconti, M.

In: Journal of Microscopy, Vol. 225, No. 2, 02.2007, p. 192-200.

Research output: Contribution to journalArticle

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