Bone mineral density assessment for research purpose using dual energy X-ray absorptiometry

Dual energy X-ray absorptiometry (DXA) has become the most common method for measuring bone mineral density (BMD) of small animals in metabolic bone disease research, and errors should be minimized in all procedures involved in research studies in order to increase the accuracy of the study results. DXA is simpler and rapid compared to Micro-computed tomography for quantitative analysis of change in trabecular bone of test subject. In human research, measuring BMD is widely used; post-operative evaluation on orthopedic surgery, evaluation of osteoporosis medication in menopause and many other areas of study. For the study, the inspector should be trained by the equipment manufacturer regarding the utilization and analysis of the equipment and regular phantom testing should be conducted to ensure the stability of the equipment, and precision tests should be conducted to analyze the positioning and data analysis. They should also be familiar with the clinical trials and conduct studies based on the approval of the Institutional Review Board. In the absolute BMD measurement of the human body, it is necessary to apply and compare the position and condition, rotation degree, region of interest, and area of the scan in the follow-up test. In the case of small animals, animal selection, measurement and equipment should be modeled to match the research. Therefore, we would like to provide information for researchers to minimize the errors, effective data management and accurate data presentation. This article reviews the process of DXA measurement for research purpose including plan for DXA examination, BMD measurement in a human body study and small animal studies.

Quality Control of DXA System and Precision Test of Radio-technologists

The image quality management of bone mineral density (BMD) is the responsibility and duty of radio-technologists who carry out examinations. However, inaccurate conclusions due to the lack of understanding and ignorance regarding the methodology of image quality management can be a fatal error to patients. The accuracy and precision of BMD measurement must be maintained at the highest level so that actual biological changes can be detected with even slight changes in BMD. Accuracy and precision should be continuously preserved for image quality of machines. Those factors will contribute to ensure the reliability of BMD examination. The enforcement of proper quality control of radiologists performing BMD inspections which brings about the durability extensions of equipment and accurate results of calculations will help the assurance of reliable inspections.

Magnetic Resonance Imaging Diagnosis in Sports Injuries / 대한스포츠의학회지

MRI (magnetic resonance imaging) is widely applied to diagnose sport-related injuries including bone and soft-tissue injuries. Because the MR characteristics of hydrogen nuclei depend upon on their local tissue environment, soft tissue structures of similar density may exhibit difference in signal intensity (brightness on image). This enables MRI to get high soft-tissue contrast resolution superior to other imaging modalities such as computed tomography (CT). Advantages of MRI are its capacity to depict occult bone trauma or bone bruise and ligamentous or tendinous injuries that are not visible on conventional radiographs. MRI does not expose the patient to radiation dose, so it can be used safely for pediatric patients. In this review, we will discuss on the osseousand soft-tissue injuries of the extremities which could be helpful from MRI in various clinical situations.

Imaging Diagnosis of Osteoporotic Fracture

Osteoporotic vertebral fractures suspected at clinical evaluation require radiological confirmation. Most radiologists make the diagnosis of vertebral fracture on the basis of a qualitative impression. However, unlike other fractures, vertebral fractures are commonly found on radiographs obtained for other reasons in patients who do not show signs or symptoms suggestive of fractures. Radiologists qualitatively analyze radiographs of the thoracolumbar spine to identify vertebral fractures in patients whose clinical indications suggest trauma, osteoporosis, malignancy, or acute back pain. The accuracy of decision-making process can be enhanced by additional radiographic projections or by complementary examinations including DXA (Dual Energy X-ray Absorptiometry) morphometry, bone scan, CT, or MRI. The importance of imaging is highlighted by the fact that only about one in four vertebral fractures is recognized on the basis of clinical evaluations without radiographs. Radiographs may include lateral and AP (anterior/posterior) X-rays of the affected spinal segments. The physician may request bone scan and/or CT to help identify the location of the fracture, its status (stable versus unstable). Furthermore, an MRI scan may be performed if neurologic deficit, soft tissue trauma or hematoma are suspected.

Appropriate Position of the Forearm for the Measurement of BMD / 대한골다공증학회지

OBJECTIVES: The aim of this study was to evaluate the appropriate position of the forearm for measuring the BMD (Bone Mineral Density). MATERIAL & METHODS: CT scanning was performed in 21 men to determine the appropriate position for the forearm. Twenty one healthy volunteers who were without any history of operations, anomalies or trauma were enrolled. CT scanning was used to evaluate the cross sectional structures and the rotation angle on the horizontal plane of the distal radius. The rotation angle was measured by the m-view program on the PACS monitor. The DXA was used for measuring 20 dried radii of cadaveric specimens in pronation and supination with 3degrees, 5degrees, 7degrees and 10degrees of rotation respectively, including a neutral position (0degrees) to evaluate the changes of BMD according to the rotation. RESULTS: The mean rotation angle of the distal radius on the CT scan was 7degrees of supination (76%, n=16), 3.3degrees of pronation (15%, n=3), and 0degrees at the neutral position (9%, n=2), respectively. The total average rotation angle in the 21 people was 5.2degrees of supination. In the cadaveric study, the BMD of the distal radius was different according to the rotational angles. The lowest BMD was obtained in 1.4degrees of pronation. CONCLUSION: In the case of the measuring of the BMD in the forearm in a neutral position, the rotational angle of the distal radius is close to supination. Therefore, pronation is needed for the constant measurement of BMD in the forearm. We recommend measuring the lowest BMD of the distal radius at about five degrees of pronation.

A Case of Adult-onset Henoch-Schonlein Purpura (HSP) Combined with Post-infectious Glomerulonephritis (PIGN) / 대한신장학회지

Henoch-Schonlein purpura (HSP) is a small-vessel vasculitis that are predominantly observed in children, affecting their skin, joints, gut and kidneys. The renal prognosis of HS nephritis is known to be worse in adults than in children. It is defined by tissue deposition of IgA. In most HSP patients, serum complement levels are usually normal. However, some authors reported abnormalities of serum complement levels in children-onset HSP. The authors report here a rare adult-onset case of HSP combined with post-infectious glomerulonephritis, especially hypocomplementemia and subepithelial 'hump'- like electron dense deposits.

Investigation on Health Effects of an Abandoned Metal Mine

To investigate potential health risks associated with exposure to metals from an abandoned metal mine, the authors studied people living near an abandoned mine (n=102) and control groups (n=149). Levels of cadmium, copper, arsenic, lead, and zinc were measured in the air, soil, drinking water, and agricultural products. To assess individual exposure, biomarkers of each metal in blood and urine were measured. beta2-microglobulin, alpha1-microglobulin, and N-acetyl-beta-glucosaminidase and bone mineral density were measured. Surface soil in the study area showed 2-10 times higher levels of metals compared to that of the control area. Metal concentrations in the groundwater and air did not show any notable differences between groups. Mean concentrations of cadmium and copper in rice and barley from the study area were significantly higher than those of the control area (p<0.05). Geometric means of blood and urine cadmium in the study area were 2.9 microgram/L and 1.5 microgram/g Cr, respectively, significantly higher than those in the control area (p<0.05). There were no differences in the levels of urinary markers of early kidney dysfunction and bone mineral density. The authors conclude that the residents near the abandoned mine were exposed to higher levels of metals through various routes.

A Case of Paragonimiasis that was Suspicious for a Lung Malignancy by PET/CT / 결핵및호흡기질환

Positron emission tomography/computed tomography (PET/CT) is valuable for the diagnosis of malignancies. However, PET/CT is unable to discriminate exactly between inflammation and a neoplasm. We report a case of a 50-year-old man with pulmonary paragonimiasis that was suspicious for lung cancer, as detected by PET/CT. The use of PET/CT revealed multilobulated consolidation on the right lung and patchy consolidation on the left lung, with increased fluorodeoxyglucose (FDG) uptake. In addition, the left paraaortic lymph node (LN) and peripancreatic LN showed enlargement with increased FDG uptake. Lung cancer with multiple lymph node metastases was suspected from the increased standardized uptake values (SUV >4.5) determined by PET/CT. We performed wedge resection via video-assisted thoracic surgery (VATS) and found Paragonimus westermani eggs in the involved tissues.

A Case of Paragonimiasis that was Suspicious for a Lung Malignancy by PET/CT / 결핵및호흡기질환

Positron emission tomography/computed tomography (PET/CT) is valuable for the diagnosis of malignancies. However, PET/CT is unable to discriminate exactly between inflammation and a neoplasm. We report a case of a 50-year-old man with pulmonary paragonimiasis that was suspicious for lung cancer, as detected by PET/CT. The use of PET/CT revealed multilobulated consolidation on the right lung and patchy consolidation on the left lung, with increased fluorodeoxyglucose (FDG) uptake. In addition, the left paraaortic lymph node (LN) and peripancreatic LN showed enlargement with increased FDG uptake. Lung cancer with multiple lymph node metastases was suspected from the increased standardized uptake values (SUV >4.5) determined by PET/CT. We performed wedge resection via video-assisted thoracic surgery (VATS) and found Paragonimus westermani eggs in the involved tissues.

Epithelioid Sarcoma in the Foot: A Case Report / 대한족부족관절학회지

Epithelioid sarcoma is a rare tumor which is usually presented with a nontender nodule on a distal extremity. It is sometimes confused with granulomatous process or chronic inflammation. We report of a case of epithelioid sarcoma on a foot of an adult male, which progressed rapidly.

Quantitative Assessment of Magnetic Resonance Imaging for the Noninvasive Evaluation of Bone Marrow Cellularity in Workers with Long-term Exposure to Solvents / 대한산업의학회지

OBJECTIVES: To develop a quantitative and noninvasive method of bone marrow cellularity evaluation in solvent-exposed painters. METHODS: Six painters (mean age 46.5 years, 5 males and one female) with hypocellular marrow, and 132 controls were examined using magnetic resonance imaging (MRI). A full examination of the peripheral blood and a bone marrow biopsy was done on each patient. Signal intensities were measured at the vertebral bodies from T12 to S1 on both the T1- and the T2-weighted image (T1WI and T2WI). Signal indices were calculated by dividing the signal indices of the vertebral bodies by that of the paraspinal muscle and the subcutaneous fat in the same view. RESULTS: The Bone marrow cellularities of the cases painters were between 20.3% and 33.6%. Signal indices based on the muscle at T1WI were greater in the cases of the painters compared to those of the controls (p<0.05, p<0.01). Signal indices based on the muscle at T1WI were significantly higher in older women compared with men (p< 0.05 ) . After adjusting for age and gender, the signal index of cases at S1 based on muscle of T1WI was higher than that of the controls by 0.364. Five of the six cases had a muscle signal index at S1 of T1WI higher than the mean + 1 standard deviation for the same age group and gender. CONCLUSIONS: MR signal indices are influenced by constitutional factors such as fat content, bone density, and the presence of other pathology. However, after adequate adjustment, it can be used as a useful indicator of bone marrow cellularity in a high-risk population.

Prevalence and risk factors of the osteoporosis of perimenopausal women in the community population / 대한내과학회지

BACKGROUND: Osteoporotic fractures pose a major public problem, not only in Western populations but also of increasing significance in Asian populations. However, most previous studies for the prevalence of osteoporosis in Korea were carried out from the data of hospitalized or out-patient based subjects, hospital staff, healthy volunteers and so forth. The purpose of present study was to evaluate the normative data of bone mineral density (BMD) in Korean young and perimenopausal women and to determine the prevalence and risk factors of low bone mass, including osteoporosis and osteopenia in a community-based population. METHODS: In 1999, a baseline survey was carried out in the Dong-gu of Ulsan city, a urban area but located in seashore of southeastern Korea. The selected community sample of 3,822 inhabitants (all were women aged 49~54 years) were chosen. We studied 1,629 women among them and 127 healthy women aged 20~35 years. BMD of lumbar spine and femur was measured using dual-energy X-ray absorptiometry. For analysis of risk factors, those were excluded who was the current or recent user of estrogen and who had osteoporosis related disease or unknown menopause due to previous hysterectomy. Thus, 1,020 subjects were analysed for the association of low BMD and risk factors. Significant determinants of BMD were investigated using univariate and multiple regression analysis. RESULTS: When our young normal data were used, 9.8% for the lumbar spine and 1.4% for the femoral neck of our study population (n=1,629) were classified as osteoporosis. Among them, the menopausal status of above 1,020 subjects had independent association with low BMD (T-score<-1.0) of both lumbar spine (odds ratio=4.71 in postmenopause, p<0.001) and femoral neck (odds ratio=2.86 in postmenopause, p<0.001). In premenopausal women (n=507), weight and age of menarche were associated independently with low bone mass, including osteoporosis and osteopenia of both lumbar spine and femoral neck. In postmenopausal women (n=513), weight and duration since menopause were associated independently with low bone mass of both lumbar spine and femoral neck. Also, daily amount of calcium intake had significant association (regression coefficient=0.047; p<0.05) independently with BMD of femoral neck. CONCLUSION: The results of this population-based study suggest that it is important to prevent bone loss and screen the BMD in women aged 49~54 years with menopause, low body weight, late menarche, prolonged duration since menopause, low calcium intake.

Relation of physical activity and calcium intake to bone mineral density in perimenopausal women

BACKGROUND: Physical activity and calcium nutriture with reproductive endocrine status are primary controller of bone remodelling activity. There are differences in impact of exercise on early menopausal bone ; late menopausal bone. There are possibility of different effect of calcium intake on bone mass among different life stage. The aim of this study was to elucidate whether the relation between lifestyle and bone mineral density varied with life stages. METHODS: We examined bone mineral density and took questionnaires related to lifestyle of 1,698 women aged 49~54 years old who lived in ulsan from July 1999 to Dec. 1999. We selected 731 healthy subjects without medical conditions or lifestyle factors known to affect bone metabolism. RESULTS: In 6~10 years postmenopausal women, those with calcium intake of more than 600 or 800mg /day showed significantly greater BMD. In postmenopausal women , those daily consumption of milk showed greater BMD. But it is not significantly. In premenopausal women with regular menstruation, those who took regular exercise showed significantly greater BMD than those who did not. Working hours is not related with BMD. CONCLUSIONS: Our study showed that the relation between calcium intake or physical activity and BMD differed with life stages. It was suggested that life stages should be taken into consideration to perform lifestyle modifications for the prevention and management of osteoporosis.

Ferumoxides-enhanced MR in the Detection of Hepatocellular Carcinoma: Comparison with Combined CT During Arterial Portography and CT Hepatic Arteriography

PURPOSE: Purpose: To compare the diagnostic accuracy of ferumoxides-enhanced MR with that of combined CT during arterial portography (CTAP) and CT hepatic arteriography (CTHA) in the preoperative detection of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: For preoperative evaluation, 20 patients with HCC underwent ferumoxides-enhanced MR and combined CTAP and CTHA. The MR protocol included fat-suppressed respiratory-triggered fast spin echo, T2*-weighted fast multiplanar gradient-recalled acquisition in the steady state, proton density-weighted fast multiplanar spoiled gradient-recalled echo, and breath-hold in-phase T1-weighted fast multiplanar spoiled gradient-recalled echo. In all patients, laparotomy was performed. The presence or absence of HCC was confirmed by pathologic examination in the resected liver and by intraoperative ultrasonography of remaining liver, or by follow up. Images were reviewed by three radiologists working independently; regarding the presence or absence of HCC in each segment, each observer assigned one of five confidence levels. A receiver operating characteristic (ROC) curve was fitted to these confidence ratings, and the diagnostic accuracy of each modality was evaluated by calculating the Az value (area under the ROC curve) and compared with that of other modalities. The sensitivity and specificity of each modality in the detection of HCC were also calculated and compared, and using a κstatistic, inter-observer agreement for each modality was assessed. RESULTS: In 28 of 160 liver segments, 30 HCCs were present. For ferumoxide-enhanced MR the mean Az value was 0.958, and for combined CTAP and CTHA this value was 0.948. The difference was not statistically significant. The mean sensitivities of ferumoxide-enhanced MR and combined CTAP and CTHA were 92.9% and 90.9%, respectively, the difference being statistically insignificant. The mean specificities of these modalities were, respectively, 98.9% and 93.6%. The difference was statistically significant. For both ferumoxide-enhanced MR and combined CTAP and CTHA, interobserver agreement was excellent. CONCLUSION: In the preoperative detection of HCC, ferumoxide-enhanced MR imaging of the liver showed a diagnostic accuracy similar to that of combined CTAP and CTHA. Its specificity, however, was higher.

Monitoring Therapy for Osteoporosis with Bone Densitometry / 대한내분비학회지

No abstract available.

The effect of audiovisual instruction that influences hormone replacement therapy uptake and changes of lifestyle behaviors related to osteoporosis in perimenopausal women

No Abstract Available.

The Relationships between Calcium Intake and Bone Mineral Density in Korean Postmenopausal Women / 한국역학회지

BACKGROUND: The evidence for a protective effect of calcium on bone mineral density is controversial. Despite this conflicting evidence an assessment of dietary calcium is often included in the clinical evaluation of osteoporosis risk. The purpose of this study was to assess the relationships between calcium intake and bone mineral density(BMD) in postmenopausal women. METHODS: The subjects consisted of 143 postmenopausal women over 40 years old who visited the Department of Family Medicine and Orthopedic Surgery in Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea from June 1997 to September 1998. They were divided into three groups such as osteoporosis, osteopenia and control groups according to the level of BMD. The BMD of the lumbar was measured by dual-energy X-ray absorptiometry. Dietary assessment was performed by semi-quantitative food frequency questionnaire. RESULTS: Total calcium intakes were directly proportional to the BMD among three groups : they were 385.5+/-298.8mg/d, 438.3+/-216.5mg/d and 548.3+/-405.3mg/d in osteoporosis, osteopenia and control groups, respectively. Multivariate analysis, which was adjusted for age, place of residence in teenage, education, body mass index, exercise, muscular strength and energy intake, was performed between osteoporosis and control groups. As a result, the odds ratio of the highest 25% vs the bottom 25% of calcium distribution by milk consumption was 0.037(95% CI 0.002~0.891). In comparison of milk consumption at least once per day with that of less than 1 time per week, the odds ratio was 0.081(95% CI 0.008~0.793). CONCLUSIONS: Levels of BMD in postmenopausal women are associated with amount and frequency of milk consumption. Therefore, more than 100mg/d of calcium intake - that is, at least a half glass of milk a day - should be recommended in postmenopausal women in order to prevent osteoporosis.

Parkinson's Disease and Osteoporosis

Parkinson's disease(PD) is characterized clinically by bradykinesia, rigidity, tremor, and disturbance of posture and equilibrium. A higher incidence of fractures in PD patient has been reported, however the studies of musculoskeletal complications in PD have been negligible. The purposes of this study were to investigate the incidence of osteoporosis and spinal compression fracture in PD patients and to evaluate whether the incidence were affected by the severity of PD. Bone mineral density(BMD) in 21 patients(5 males and 16 females) with idiopathic PD was measured by dual energy X-ray absorptiometry(DXA) and compared with an age adjusted control group(32 females). The patients were divided into two groups according to the Hoehn and Yahr(H-Y) stage as mild or severe and the BMD was compared. Simple x-ray studies of thoracolumbar spine were performed to find out the presence of spinal compression fractures. The results showed that the BMD of PD patients was significantly lower than control subjects. The PD patients with high H-Y stage(severe group) had lower BMD scores with no statistical significance. The spinal compression fractures were noted mainly at mid-thoracic area and thoraco-lumbar junction. Spinal t-score in patients with a compression fracture was significantly reduced. No significant correlation exists between back pain and a compression fracture.

The Effects of Growth Hormone Tretment on Body Composition and Glucose Metabolism in Adult Hypophysectomized Rats / 대한내분비학회지

BACKGROUND: It is well known that growth hormone (GH) stimulates animal growth, but studies on metabolic effects of growth hormone have recently been increasing. The purpose of this study was to clarify the effects of growth hormone treatment on body composition and glucose metabolism in hypophysectomized growth hormone-deficient rats. METHODS: The 20-week-old rnale Sprague-Dawley rats were hypophysectomized and replaced with cortisol and thyroxine for 8 weeks, then administered with recombinant human growth hormone for 2 weeks. Group 1 consisted of intact controls (n 15), while group 2 consisted of hypophysectomized controls (n 12), and group three consisted of those with GH treatment (n 13). The body weights, body composition, blood glucose levels, plasma insulin-like growth factor-I (IGF-I) levels, euglycemic hyperinsulinemic clamp test, and glycogen synthase activities in gastrocnemius muscle were measured before and after growth hormone treatment. RESULTS: Plasma IGF-I levels in GH-treated group increased to intact control group levels after 2 weeks of GH treatment. There were significant changes in body composition after the treatment (fat mass significantly decreased and lean body mass significantly increased). There were no changes in glucose metabolism in peripheral tissue after 2 weeks of GH treatment. CONCLUSION: Human GH treatment (4 IU/kg/day) in adult hypophysectomized GH-deficient rats changed the body composition, but did not alter the glucose metabolism in peripheral tissue.

Multiple Bony Lesions other than Femoral Heads on

PURPOSE: To evaluate the clinical significance of the multiple increased uptake lesions other than in femoral heads as seen on whole body bone scan in patients with avascular necrosis of femoral heads. MATERIALS AND METHODS: One hundred and seventy three patients with clinical diagnosis of avascular necrosis of fthe emoral head underwent a bone scan using Tc-99m MDP. Increased uptake lesions other than in femoral heads were evaluated, including frequency and common sites of involvement, and correlated with clinical information and plain radiographic findings. Two hundred patients without AVN, who had undergone a bone scan, were included as a control group. RESULTS: Increased uptake lesions in extrafemoral head locations were found in 36 of 173 patients(20.8% ; the location of 79 lesions was other than the femoral head, This result is statistically different from patients without avascular necrosis of femoral head(p<0.0001). The most common site of involvement was the knee joint area(62.5%). Other lesions were located in the mid-shafts of the long bones of the lower extremities, calcaneus, proximal humerus, etc., in order of decreasing frequency. Plain radiographs of 17 lesions were nonspecific, except for three lesions showing definite changes associated with avascular necrosis. The risk factors included alcoholism, the prolonged use of steroids, renal transplantation, herbal medication and working as a working as deep-sea diver. Most patients did not complain of pain, except for two with irreversible osteonecrotic changes as seen on plain radiograph. CONCLUSION: in patients with avascular necrosis of the femur, increased uptake lesions other than in the femoral head as seen on bone scan, may represent the early stage of osteonecrosis, which shows a characteristic appearance on bone scan. In order to avoid possible misdiagnoses of multiple extrafemoral lesions as bony metastasis or traumatic lesions, in patients with avascular necrosis of the femur these should be carefully evaluated.