Assessment of BMD and Statistical Analysis for Osteoporosis Detection

Biomedical engineering is one of the promising disciplines in engineering that deals with technology advancement in human health. Osteoporosis is a common metabolic disease categorized by decreased bone mass and increased liability to fractures. Bone densitometry is a broad term comprising the art and science of measuring the bone mineral content (BMC) and bone mineral density (BMD) of particular skeletal sites or the whole body. There are various methods to measure bone mineral density which differs based on the differential absorption of ionizing radiation or the sound waves. The methods are SPA (Single Photon Absorptiometry), DPA (Dual Photon Absorptiometry), SEXA (Single Energy X ray Absorptiometry), DEXA (Dual Energy X ray Absorptiometry), QCT (Quantitative Computed Tomography), QUS (Quantitative Ultra Sound) and RA (Radiographic absorptiometry). The DEXA test can measure the whole body but usually the lower spine and hips. A major disadvantage of DEXA is that currently there is a lack of standardization in bone and soft tissue measurements. Furthermore, for a given manufacturer, results may vary by the model of the instrument, the mode of operation or the version of the software used to analyze the data. In addition to that, DEXA scan images are only for the confirmation of correct positioning of the patient and correct placement of the regions of interest (ROI). Motivated by the above issues, this paper can pave a way for analysis in the measurement of BMD, measurement of T-score, and Z-score from the DEXA scan images. This proposed methodology includes segmentation algorithms such as k means clustering & mean –shift algorithm and comparison of the accuracy of algorithms. Also in addition, a novel mathematical analysis is also proposed to measure the T–score values in DEXA images with a new parameter ‘S’ from BMD values in order to detect the osteoporosis condition accurately.

Validation of single photon absorptiometry for on-farm measurement of density and mineral content of tail bone in cattle

A validation study examined the accuracy of a purpose-built single photon absorptiometry (SPA) instrument for making on-farm in vivo measurements of bone mineral density (BMD) in tail bones of cattle. In vivo measurements were made at the proximal end of the ninth coccygeal vertebra (Cy9) in steers of two age groups (each n = 10) in adequate or low phosphorus status. The tails of the steers were then resected and the BMD of the Cy9 bone was measured in the laboratory with SPA on the resected tails and then with established laboratory procedures on defleshed bone. Specific gravity and ash density were measured on the isolated Cy9 vertebrae and on 5-mm2 dorso-ventral cores of bone cut from each defleshed Cy9. Calculated BMD determined by SPA required a measure of tail bone thickness and this was estimated as a fraction of total tail thickness. Actual tail bone thickness was also measured on the isolated Cy9 vertebrae. The accuracy of measurement of BMD by SPA was evaluated by comparison with the ash density of the bone cores measured in the laboratory. In vivo SPA measurements of BMD were closely correlated with laboratory measurements of core ash density (r = 0.92). Ash density and specific gravity of cores, and all SPA measures of BMD, were affected by phosphorus status of the steers, but the effect of steer age was only significant (P < 0.05) for steers in adequate phosphorus status. The accuracy of SPA to determine BMD of tail bone may be improved by reducing error associated with in vivo estimation of tail bone thickness, and also by adjusting for displacement of soft tissue by bone mineral. In conclusion a purpose-built SPA instrument could be used to make on-farm sequential non-invasive in vivo measurements of the BMD of tailbone in cattle with accuracy acceptable for many animal studies.

GLYCOSAMINOGLYCAN CHANGES IN REGENERATIVE MENISCI OF THE IMMATURE RABBITS — HISTOLOGICAL AND SPECTROPHOTOMETRIC QUANTITATION

Purpose: This study was conducted primarily to compare the contents and distribution of Glycosaminoglycan (GAG) in the normal and regenerated menisci, and partly to elucidate the role of GAG in the meniscus to fulfill its function. Method: A total of 60 immature rabbits, weighing 300–400 gm and aged 4 weeks, were used for the study. Total medial meniscectomy in the right knee joint was performed in all rabbits. The medial menisci of the left knee joints were used as control. After 16, 20, 24 and 28 weeks postoperatively, the amount of GAG in normal and regenerated menisci were measured. For the measurement of quantity and distribution of GAG contents, photon absorptiometry and Safranin O staining method were used. Results: (1) In 48 of the 60 medial meniscectomized knees, menisci were regenerated in various sizes with degenerative changes of joints, especially on tibial side. (2) In normal menisci, GAG was distributed at inner and middle 1/3, while GAG in regenerated menisci was diffusely found in the entire width. (3) The concentration of GAG per 1 mg of regenerated menisci were 4.36 ± 1.68, 4.58 ± 1.14, 4.65 ± 2.21, 4.60 ± 2.06 μg in each 16, 20, 24, and 28 week groups, while those of normal menisci were 9.10 ± 2.09, 9.75 ± 3.97, 11.80 ± 8.44 and 14.51 ± 8.91 μg. (4) In normal menisci, the amount of GAG was gradually increased as rabbit got older. However, there was no statistical differences of quantitative amount of GAG of regenerated menisci among the 16, 20, 24, and 28 weeks groups during the observation periods (p > 0.05). (5) There was a distinctive difference in Safranin O stainability by every 4 μg increase of GAG in both 1 mg of normal and regenerated menisci. Conclusion: This study showed the quantitative change of GAG between normal and regenerated menisci, and comparative analysis of GAG contents in the menisci by biochemical method and histological method were found to be useful tools.

Methods to determine the dry matter content of roundwood deliveries

In pulp production, the dry matter content of pulpwood affects debarking and pulping. For pulpwood to be traded due to its dry weight, a prerequisite is that the measurement of dry be done quickly and accurately. No current method fulfils these requirements, although there are different methods that have the potential to determine the dry matter content in wood. These techniques include radar, gamma rays, dichromatic photon absorptiometry, computed tomography, near infrared (NIR), nuclear magnetic resonance (NMR), and radio frequency (RF). A literature review showed that several of the techniques can determine the dry matter content with an acceptable error. Several of the methods cannot handle frozen or semifrozen samples, which disqualifies them as an acceptable method. NIR, dichromatic photon absorptiometry, and RF techniques might have the potential to meet the requirements of fast measurement with high accuracy