No abstract available.
Densitometry*

No abstract available.
Densitometry* ; Osteoporosis*

PURPOSE: To evaluate the effect of reconstruction algorithms on the CT measurement of mean lung mass density and normal thoracic structures. MATERIALS AND METHODS: Forty-six patients with a 2-9cm-sized lung mass underwent thoracic CT examinations with intravenous contrast enhancement and using a CT HiSpeed Advantage scanner (GE Medical Systems). In each examination, the axial image of the lung mass was reconstructed using soft, standard, detail, and bone algorithms. The mean value and standard deviation of mass density in Hounsfield Units (HU) were measured using ROIs of three different sizes (50 mm2, 200 mm2, and 350 mm2 or more), and the same method was used to measure the density of normal lung, muscle, bone, and vessels. In 21 patients, mass density was also measured on unenhanced and delayed enhanced images and the degree of enhancement was calculated. RESULTS: The average maximum difference in mean mass density in the images of the four different algorithms was less than 1 (range, 0.1 -1.9) HU (ROI size, 350 mm2 or more), 0 -4.2 HU (200 mm 2), and 0.1 -3.6 HU (50mm2). The average maximum difference in the degree of lung mass enhancement was 0.5 -1.2 (range, 0 -1.6 )HU (ROI size, 350 mm2 or more). The mean density of the four normal thoracic structures was highest in images reconstructed with the bone algorithm, though there was no significant difference between the four different algorithms (p = 1.000). CONCLUSION: The measured mean CT density of a lung mass larger than 2 cm does not significantly change according to the reconstruction algorithm used. When using a small ROI, however, the density difference may increase.
Densitometry* ; Humans ; Lung*

OBJECTIVETo determine densities of mineral drugs and their calcined products by using sealing wax densimetry, and to establish the testing method of crispness for calcined traditional Chinese medicine.

METHODTaking density as detection indicator, the accuracies of mineral drugs and their calcined products were investigated by sealing wax densimetry compared with direct densimetry, and the method of density determination was optimized.

RESULTThe density values measured by two methods investigated above were significantly different (P < 0.01), the density values of Pyritum, Haematitum, calcined Pyritum and calcined Haematitum measured by direct densimetry were increased 1.66%, 9.43%, 96.72% and 9.02%, respectively compared with that measured by sealing wax densimetry.

CONCLUSIONSealing wax densimetry is suitable for the density determination of mineral drugs and their calcined products with its high accuracy, whereas direct densimetry'is not suitable for the density determination of mineral drugs and their calcined products.

The Scheimpflug photography was used to evauate objectively changes in lens opacity at a month interval in 143 eyes of 78 patients affected by early cataract. from Dec. 1993 to Dec. 1994. A total of 48 patients were treated daily with 1.5g bendazac-lysine, and 30 patients constituted the control group. We checked visual acuity and analyzed change of lens opacity by using axial densitometry and retroillumination of Scheimpflug photography after Bendaline(R) medication up to 9 months After treatment, improvement or no change of subjective visual acuity was observed in 65 eyes(78.3%) of treated group, whereas decrement in 35 eyes (58.3%) of control group. In the axial densitometry, the nuclear opacity began to improve after 3 months of medication and opacities of lens between anterior supranucleus and posterior capsule were statistically significant improved after 5 months of medication (p<0.05). There's no correlation in the change of opacity area under retroillumination (p>0.05). The result show that bendazac lysine may be effective in improvement of visual acuity and delay the formation of lens opacity in early cataract.
Cataract* ; Densitometry ; Humans ; Lysine ; Photography ; Visual Acuity

PURPOSE: To evaluate the correlation between nuclear density measured using the Pentacam(R) (Oculus Optikgerate GmbH, Wetzlar, Germany) Scheimpflug imaging system and phacoemulsification parameters. METHODS: The nuclear density was measured using maximal nuclear density with ImageJ, Pentacam(R) nucleus staging (PNS), average value and maximal value in lens densitometry. Intraoperatively, effective phaco time (EPT) and balanced salt solution (BSS) used were noted and compared with the nuclear density calculation methods. As an index of corneal endothelial cells, the changes in cell density (CD) were compared with the nuclear density. RESULTS: Regarding EPT, maximal nuclear density with ImageJ (r = 0.379, p < 0.01) and PNS (r = 0.367, p < 0.01) were correlated positively, but the other methods were not correlated. Concerning BSS used, maximal nuclear density with ImageJ (r = 0.279, p = 0.03) and PNS (r = 0.286, p = 0.04) were positively correlated, but the other methods were not correlated. The specular microscopy showed that as the nuclear density increased, the postoperative CD tended to decrease, but without statistical significance. CONCLUSIONS: Preoperative nuclear density measurements using maximal nuclear density with ImageJ or PNS were correlated with phacoemulsification parameters.
Cell Count ; Densitometry ; Endothelial Cells ; Microscopy ; Phacoemulsification*

OBJECTIVE: The purpose of this study was to compare the results of three types of short segment screw fixation for thoracolumbar burst fracture accompanying osteopenia. METHODS: The records of 70 patients who underwent short segment screw fixation for a thoracolumbar burst fracture accompanying osteopenia (-2.5< mean T score by bone mineral densitometry <-1.0) from January 2005 to January 2008 were reviewed. Patients were divided into three groups based on whether or not bone fusion and bone cement augmentation procedure 1) Group I (n=26) : short segment fixation with posterolateral bone fusion; 2) Group II (n=23) : bone cement augmented short segment fixation with posterolateral bone fusion; 3) Group III (n=21) : bone cement augmented, short segment percutaneous screw fixation without bone fusion. Clinical outcomes were assessed using a visual analogue scale and modified MacNab's criteria. Radiological findings, including kyphotic angle and vertebral height, and procedure-related complications, such as screw loosening or pull-out, were analyzed. RESULTS: No significant difference in radiographic or clinical outcomes was noted between patients managed using the three different techniques at last follow up. However, Group I showed more correction loss of kyphotic deformities and vertebral height loss at final follow-up, and Group I had higher screw loosening and implant failure rates than Group II or III. CONCLUSION: Bone cement augmented procedure can be an efficient and safe surgical techniques in terms of achieving better outcomes with minimal complications for thoracolumbar burst fracture accompanying osteopenia.
Bone Diseases, Metabolic ; Congenital Abnormalities ; Densitometry ; Follow-Up Studies ; Humans

BACKGROUND: Although dual energy X-ray absorptiometry (DXA) is known to standard equipment for bone mineral density (BMD) measurements. Different results of BMD measurement using a number of different types of devices are difficult to use clinical practice. The purpose of this study was to evaluate discrepancy and standardizations of DXA devices from three manufactures using a European Spine Phantom (ESP). METHODS: We calculated the accuracy and precision of 36 DXA devices from three manufacturers (10 Hologic, 16 Lunar, and 10 Osteosys) using a ESP (semi-anthropomorphic). The ESP was measured 5 times on each equipment without repositioning. Accuracy was assessed by comparing BMD (g/cm2) values measured on each device with the actual value of the phantom. Precision was assessed by the coefficient of variation (CVsd). RESULTS: Lunar devices were, on average, 22%, 8.3%, and 5% overestimation for low (L1) BMD values, medium (L2), and high (L3) BMD values. Hologic devices were, on average, 6% overestimation for L1 BMD, and 5% and 6.2% underestimation for L2 and L3 BMD values. Osteosys devices was, on average, 12.7% (0.063 g/cm2), 6.3% (0.062 g/cm2), and 5% (0.075 g/cm2) underestimation for L1, L2, and L3, respectively. The mean CVsd for L1-L3 BMD were 0.01%, 0.78%, and 2.46% for Lunar, Hologic, and Osteosys devices respectively. CONCLUSIONS: The BMD comparison in this study demonstrates that BMD result of three different devices are significant different between three devices. Differences of BMD between three devices are necessary to BMD standardization.
Absorptiometry, Photon ; Bone Density ; Densitometry* ; Lumbar Vertebrae ; Spine*

Computer densitometry using MATLAB 4.2b [The MathWorks, Inc.] was developed for the quantitiative measurement of diffuse retinal nerve fiber layer [RNFL] atrophy. Intra- and inter-operator reliability and clinical validity of densitometry were evaluated. Twenty-one RNFL photographs of 21 patients that show varying degrees of atrophy underwent computer densitometry by two operators on two separate occasions. And the association between RNFL measurements and retinal sensitivity was investigated. Coefficient of variation in the densitometric measurements was 1.2~5.4%. Intra-and inter-oprator reliabilities were excellent [Pearsons correlation coefficient > 0.96, p=0.00]. The agreement between total density variations in the upper and lower ninety degrees along the circle of 1.5 and 2.5 times optic disc radius and retinal sensitivity of Humphrey C30-2 visual field was moderate [Spearmans correlation coefficient=0.52 -0.54, p=0.00]. Computer densitometry of RNFL photographs provides objective and quantitative measurement of diffuse RNFL atrophy.
Atrophy ; Densitometry* ; Humans ; Nerve Fibers* ; Radius ; Retinaldehyde* ; Visual Fields

BACKGROUND: The confgurations of the skin surface, as characterized by surface furrows and plateaux, are known to change with ageing. There are many parameters to analyze the effects of ageing processes on the surface configuration. However, there are contradictory results among the authors. OBJECTIVE: The purpose of this study was to compare the sensitivity of various parameters being described in other reports with our new parameters used in evaluating the changes of the skin surface in the agein processes. METHODS: 112 healthy Korean males in 4 age groups participated in this study. Silicon skin replicas were taken from medial and lateral aspects of the forearm. Images of the skin replicas were analyzed by means of a digital image processing system (AIC, GA). Most parameters were calculated and measured in the primary skin axis. Image analyses were porformed by 3 different processes i.e., morphometry, densitometry (optical profilometry), and histograms. RESULTS: In Morphometry, the furrow count in the vertical section (VFC), the coefficient of the developed skin surface (CDSS) and mean width at maximal interception (MWMI) showed a tendencies to decrease with ageing.Irregularity of shadow shape (ISS) showed a tendency to increase with ageing. In Densitometry, the mean surface roughness(Ra) and mean depth of roughness(Rz) showed a tendency to increase with ageing. On histogram analysis, skewness was decreased with ageing but kurtosis did not show any significant changes. CONCLUSION:Ra, Rz, and ISS have shown a tendency to increase in the ageing processes (p<0. 05). VFC, CDSS, MWMI and skewness showed tendencies to decrease with ageing but the results were not statistically significant. The different results between morphometry and densitometry are likely to be due to increrr ent angles in the skin furrows with ageing.
Axis, Cervical Vertebra ; Densitometry ; Forearm ; Humans ; Male ; Silicones ; Skin*