PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 11702138

Stereolithographic models simulating trabecular bone and their characterization by thin-slice- and micro-CT.

K Engelke·C Süss·W A Kalender
View original source ↗Export metadata ↓

Abstract

The analysis of bone structure in vivo is an important goal in osteoporosis, because the determination of bone mineral density alone is insufficient to predict whether an individual patient will eventually suffer an osteoporotic fracture or not. An additional structural analysis may significantly improve the statistical assessment of fracture risk. In this study we present a method to generate realistic although enlarged 3D phantoms of trabecular bone. These phantoms are useful in characterizing the potential of in vivo imaging procedures for the analysis of bone structure and to verify textural or structural analysis methods applied to these images. Our phantoms are based on a real trabecular bone specimen that was converted to a plastic model using the technique of stereolithography. The trabecular network is modeled by hydroxyapatite. Limitations of the stereolithographic process prevent the generation of exact 1:1 replicas of the real bone. A histomorphometric analysis of microCT scans of the phantoms showed that an excellent replication of the bone structure could be achieved in phantoms enlarged by a factor of 2.5 with "trabecular" hydroxyapatite concentrations up to 400 mg/cm3. In order to demonstrate the usefulness of our phantoms, we investigated one of them with various thin-slice CT protocols using clinical single- and multi-slice spiral CT scanners. The enlargement of the phantoms limits their use on high spatial resolution CT scanners (resolution >20 lp/cm). The limited hydroxyapatite concentration requires enhanced exposure rates for the phantoms scans to offset the larger impact of noise due to the lower contrast in the phantoms.

Explore related subjects

Bone and BonesModels, AnatomicPhantoms, ImagingTomography, X-Ray ComputedJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

K Engelke, C Süss, W A Kalender. 2001. Stereolithographic models simulating trabecular bone and their characterization by thin-slice- and micro-CT.. https://doi.org/10.1007/s003300100927

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Cytogenetic and molecular cytogenetic findings in dedifferentiated liposarcoma with neural-like whorling pattern and metaplastic bone formation.

Dedifferentiated liposarcoma is a subtype of liposarcoma characterized by juxtaposition of well-differentiated liposarcoma with a nonadipocytic sarcoma. A peculiar form of dedifferentiated liposarcoma has been described, characterized by a nonlipogenic component with a neural-like whorling pattern of growth and metaplastic bone formation. We report the cytogenetic and molecular genetic findings of this peculiar form of dedifferentiation in a retroperitoneal tumor found in a 58-year-old female. The neoplasm had typical histologic findings and a complex karyotype characterized by several numeric and structural chromosomal abnormalities, including the presence of ring and giant rod chromosomes. Molecular cytogenetic studies found high levels of amplification of the MDM2 oncogene, consistent with the amplification of the 12q14 chromosome band, a cytogenetic abnormality commonly found in these tumors. These findings indicate that, despite its unique and peculiar morphologic features, this unusual type of dedifferentiated liposarcoma shares many of the cytogenetic features and molecular genetic abnormalities found in other forms of dedifferentiation. The specific cytogenetics and molecular determinants of these peculiar morphologic findings, however, remain unknown.

Bone and Bones↗
PubMed2007

Traditional and virtual microscopy compared experimentally in a classroom setting.

The technology known as virtual microscopy is now widely available to medical students. A number of medical school histology and pathology course directors, including those at the Eastern Virginia Medical School, are exploring the question of how best to make use of this new tool. The current study compared the efficacy of teaching and testing one unit of histology, bone and cartilage, using two technologies, namely, virtual microscopy and traditional microscopy. Additionally, the study examined whether low, moderate, high moderate, or high achieving students perform more effectively in any of the learning/testing formats. In a completely randomized block design, 96 first semester, first-year medical students were grouped by previous exam quartiles then subsequently randomly assigned to one of four groups. Using identical laboratory exercises with highly comparable slides for each experimental group, half of the subjects learned the exercise with traditional microscopy and half learned with virtual microscopy. Subjects were further randomly subdivided into virtual or actual testing groups. The authors found no significant differences in test scores when they examined effects by learning group or by testing group, nor were there significant interaction effects. Student performance evaluated by previous exam quartile was significant (P < 0.001). That is, students who had scored in a particular quartile on a previous test tended to score in the same quartile on the bone and cartilage test regardless of learning or testing method. In a short opinion survey, students were polled to evaluate their experience. Student preferences for both learning and testing method varied widely.

Bone and Bones↗