• Structural Engineering and Mechanics
• /
• v.48 no.4
• /
• pp.501-518
• /
• 2013

Apart from thinning of cortical layers, the local bone curvature, varying along bone periphery, modulates ultrasound waves as well, which is however often underestimated or overlooked in clinical quantitative ultrasound (QUS). A dedicated three-dimensional finite element modelling technique for cortical bones was established, for quantitatively exploring and calibrating the effect of local curvature of cortical bone on ultrasound. Using a correlation-based mode extraction technique, high-velocity group (HVG) and low-velocity group (LVG) wave modes in a human radius were examined. Experimental verification using acrylic cylinders and in vitro testing using a porcine femur were accomplished. Results coherently unravelled the cortical curvature exerts evident influence on bone-guided ultrasound when RoC/${\lambda}$ <1 for HVG mode and RoC/${\lambda}$ <2 for LVG mode (RoC/${\lambda}$: the ratio of local bone curvature radius to wavelength); the sensitivity of LVG mode to bone curvature is higher than HVG mode. It has also been demonstrated the local group velocity of an HVG or LVG mode at a particular skeletal site is equivalent to the velocity when propagating in a uniform cylinder having an outer radius identical to the radius of curvature at that site. This study provides a rule of thumb to compensate for the effect of bone curvature in QUS.

• Journal of Biomedical Engineering Research
• /
• v.16 no.3
• /
• pp.359-366
• /
• 1995

The parameter, B/A, quantifies nonlinearity of the pressure-density relationship of propagation medium. This study investigated quantitative evaluation technique for healing fractured bones using this ultrasonic nonlinear parameter, B/A, obtained by the second harmonic amplitude method. A series of fundamental experiments were performed on cylinder phantoms made of aluminium, which demonstrated potential capability of nonlinear parameter B/A in the diagnosis of healing fractured bones using ultrasound.

• Journal of muscle and joint health
• /
• v.12 no.1
• /
• pp.39-47
• /
• 2005

Purpose: To identify Osteoporosis and the related risk factors in middle-aged women, the descriptive survey was done. Method: The subjects were measured in 465 residents who were 40-60 aged healthy women. They underwent ultrasound measurement and health examination in G city's Health Center in Gyeonggi-do, Korea from July 2000 to March 2001. The self-reported questionnaire consisted of total 17 items about risk factors related to osteoporosis. The evaluation of bone density was based on ultrasound measurements of right heel. All data were analyzed by SAS-PC Program. Result: Mean age of the subjects was 46.7. Mean T score related to bone density was -1.30, ranged from -3.52 to 3.06. In diagnosis classification according to T score, 74.8% of subjects was normal, 12.9% was osteopenia, 12.3% was osteoporosis. Among risk factors, there were significant differences by age (t=15.35. p=0.000), parity (F=12.81, p=0.000), menopause status (t=22.05, p=0.000), period after menopause (F=5.20, p=0.006). The higher frequency of delivery, postmenopausal and longer period after postmenopause of subjects had the lower the bone density. Conclusion: It would be necessary to develop and apply the community-based health promotion program for middle-aged women to prevent osteoporosis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.13
• /
• pp.5487-5492
• /
• 2014

Ultrasonography is non-invasive and can give useful clues in the diagnosis of cervical lymphadenopathy, However, differential diagnosis is difficult in some situations even combined with color Doppler imaging. The present study was conducted to evaluate the clinical value of real time elastography in patients with unexplained cervical lymphadenopathy using a quantitative method. From May 2011 to February 2012, 39 enlarged lymph nodes from 39 patients with unexplained cervical lymphadenopathy were assessed. All the patients were examined by both B-mode ultrasound, color Doppler flow imaging and elastography. The method of analyzing elasto-graphic data was the calculation of the 10 parametres ("mean", "sd", "area%", "com", "kur", "ske", "con", "ent", "idm", "asm") offered by the software integrated into the Hitachi system. The findings were then correlated with the definitive tissue diagnosis obtained by lymph node dissection or biopsy. Final histology revealed 10 cases of metastatic lymph nodes, 11 cases of lymphoma, 12 cases of tuberculosis and 6 cases of nonspecific lymphadenitis. The significant distinguishing features for conventional ultrasound were the maximum short diameter (p=0.007) and absent of echogenic hilum (p=0.0293). The diagnostic accuracy was 43.6% (17/39 cases) and there were 17 patients with equivocal diagnosis. For elastography, "mean" (p=0.003), "area%" (p=0.009), "kurt" (p=0.0291), "skew" (p=0.014) and "cont" (p=0.012) demonstrated significant differences between groups. With 9 of the 17 patients with previous equivocal diagnoses (52.9%) definite and correct diagnoses could be obtained. The diagnostic accuracy for conventional ultrasound combined elastography was 69.2% (27/39 cases). There were differences in the diagnostic sensitivity of the two methods (p=0.0224). Ultrasound combined with elastography demonstrated higher rates of conclusive and accurate diagnoses in patients with unexplained cervical lymphadenopathy than conventional ultrasound. The quantitative program showed good correlation with the pathology of different lymph node diseases.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.1
• /
• pp.430-437
• /
• 2018

Ultrasonic attenuation is an important parameter in Quantitative Ultrasound and many algorithms have been proposed to improve estimation accuracy and repeatability for multiple independent estimates. In this work, we propose an improved algorithm for estimating ultrasonic attenuation utilizing the optimal frequency compounding technique based on stochastic noise model. We formulate mathematical compounding equations in the AWGN channel model and solve optimization problems to maximize the signal-to-noise ratio for multiple frequency components. Individual estimates are calculated by the reference phantom method which provides very stable results in uniformly attenuating regions. We also propose the guideline to select frequency ranges of reflected RF signals. Simulation results using numerical phantoms show that the proposed optimal frequency compounding method provides improved accuracy while minimizing estimation bias. The estimation variance is reduced by only 16% for the un-compounding case, whereas it is reduced by 68% for the uniformly compounding case. The frequency range corresponding to the half-power for reflected signals also provides robust and efficient estimation performance.

• Journal of the Korean Society for Precision Engineering
• /
• v.24 no.11
• /
• pp.29-36
• /
• 2007

• The Journal of Korean Physical Therapy
• /
• v.25 no.2
• /
• pp.76-80
• /
• 2013

Purpose: The objective of this study was to offer primary clinical data examining whether change of imaging structure and quantitative evaluation of muscle activity on myofascial trigger points can lead to implementation of an analytical technique for evaluation of myofascial pain diagnoses. In addition, we examined the effect of a variety of mediation techniques, in order to examine neuromuscular physiological characteristics of myofascial trigger points muscle by comparing differences in pressure pain threshold and ultrasound imaging. Methods: Participants in the study included 30 adults in their twenties. The subjects were divided into the normal and myofascial trigger points groups. Clinical outcomes were evaluated by pressure pain threshold for pain and ultrasound imaging was performed for evaluation of the structural characteristics of muscle. Independent t-test was used for statistical analysis. Results: The two groups showed statistical significance in the change in pressure pain threshold (p<0.05). Findings of ultrasound imaging analysis showed no significant differences, increased muscle thickness was observed (p>0.05). Findings of ultrasound imaging analysis showed significant differences, increased muscle echodensity was observed (p<0.05). Findings on ultrasound imaging analysis showed significant differences, increased muscle white area index was observed (p<0.05). Conclusion: From these results, active myofascial trigger points muscle showed quality deterioration on ultrasound imaging. Thorough evaluation of imaging structure and physiological characteristics can be useful quantitative analytical techniques for diagnosis of myofascial pain syndrome and a primary factor reflected in physical therapy intervention.

• Journal of the Korean Physical Society
• /
• v.73 no.12
• /
• pp.1849-1854
• /
• 2018

The present study aims to investigate the feasibility of using a simple nonlinear acoustic method for the assessment of bone status and osteoporosis in trabecular bone. Correlations of linear and nonlinear ultrasound parameters with the apparent bone density were obtained in 32 bovine femoral trabecular bone samples. Highly significant positive correlations were observed between the apparent bone density and the two linear ultrasound parameters, the speed of sound (SOS) and the normalized broadband ultrasound attenuation (nBUA), with Spearman's correlation coefficients of r = 0.85 and 0.77. In contrast, the apparent bone density was found to be negatively correlated with the nonlinear ultrasound parameter introduced in the present study, the logarithmic difference between the power spectrum levels of the fundamental frequency and the second harmonic (PSL1-PSL2), with the highest correlation coefficient of r = -0.92. These results suggest that the PSL1-PSL2, in addition to the SOS and the nBUA, may be useful for the assessment of bone status and osteoporosis.

• Journal of the Korean Dietetic Association
• /
• v.13 no.3
• /
• pp.240-249
• /
• 2007

The objective of this study was to investigate the relation of serum calcium level, body mass index(BMI) with bone status expressed as broadband ultrasound attenuation(BUA) measured by quantitative ultrasound (QUS) and the occurrence of osteopenia among adult men and women. Two hundred eleven(63 male and 148 female) workers who worked in 4 different battery factories were recruited from March 2005 to October 2005. BUA was used as a surrogate of bone mineral density and measured at left calcaneous bone area. The BUA value transformed into T-score by WHO standard conversion criteria to determine osteopenia (-2.5

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.2 no.2
• /
• pp.94-98
• /
• 2009

Acupuncture is a treatment method that originated more than 3,000 years ago in China and is practiced in most of the world. Acupuncture became the most popular complementary and alternative medicine modality. Ultrasound is useful for research and educational purposes, visualizing needle insertion at acupuncture points, especially next to vulnerable structures such as nerves or the pleura. Additionally, ultrasound is an ideal imaging method for evaluation the biomechanical effects of needle manipulation on tissue and has the distinctive advantage of yielding both images of tissue morphology and biomechanical information. Elastography take aim at quantifying a mechanical response or the mechanical property of tissues from a mechanical stimulus, generated internally or externally. Therefore, the combination of ultrasound and elastography analyses allows quantitative assessment of dynamic changes in the structure of human connective tissue.