OBJECTIVES: Bone densitometry is a current method for evaluating skeletal status, assessing osteoporosis, and determining fracture risk. DEXA has rapidly become a dominent method for evaluating skeletal status. But the comparison of patient data among different DEXA scanners is complicated because the instruments show differences in scanner design, bone mineral calibration, and analysis algorithms. The purpose of this study is making standardization of DEXA and comparability among different DEXA system. METHODS: Posteroanterior lumbar spine (L2-IA) measurements of healthy 83 racially homogenous Korean women, age 38-66 years (mean +/- 516, range of BMD 0.624-1.574g/cm) were obtained on a Lunar DPX-L, a Hologic QDR-2000, and a Norland XR-36. All sujects had no spinal deformities, ostophytes, fracture and scoliosis on thoracolumbar spinal X-ray. We performed the measurement of BMD in each subjects with different three scanners at the same time. RESULTS: The results of cross-calibration spinal BMD (L2-4, g/cm2) in patient study (r2=0.972-0.974); Lunar DPX-L=(1.149 X Hologic)+0.008=(1.022 X Norland)+0.137, Hologic QDR-2000=(0.847 X Lunar)+0.019= (0.876 X Norland)+0.124, and Norland XR-36=(0.954 X Lunar)-0.107=1.110 X Hologic)-0.113. The average absolute difference in patients` spinal BMD values (L2-L4) between Lunar and Hologic was 0.146g/cm2 (14%); it was 0.156g/cm2 (15%) between Lunar and Norland and 0.010g/cm2 (1%) between Hologic and Norland. CONCLUSIONS: The formula of this cross-calibration shows good correlation. We conclude that it is possible to compare the different spinal BMD values obtained on the different DEXA scanners.
Absorptiometry, Photon* ; Bone Density ; Calibration ; Congenital Abnormalities ; Densitometry ; Female ; Humans ; Osteoporosis ; Scoliosis ; Spine

A nationwide survey of chigger mites causing scrub typhus and an investigation of epidemiologic factors for chigger mites was conducted at 16 localities in 8 provinces in Korea during autumn 2009, 2012, and 2013. A total of 233 Apodemus agrarius were captured, and all were infested with chigger mites. The chigger index was highest in Chungcheongbuk-do in 2009 (358.3) and 2012 (290.1) and Chungcheongnam-do in 2013 (294.4). The predominant chigger mite species was Leptotrombidium pallidum in the northern and central parts and L. scutellare in the southern and western parts, Korea. L. pallidum was not found in Jellanam-do and Gyeongsangnam-do and the distribution of L. scutellare had been expanded in the northern parts of Korea. The chigger index of L. pallidum was positively correlated with temperature and negatively correlated with humidity. The incidence of scrub typhus is dependent on L. scutellare index. These findings could be helpful to monitor the distribution of chigger mites and to develop a preventive measures for scrub typhus in Korea.