scholarly journals Acquisition of Quasi-Monochromatic Dual-Energy in a Microfocus X-ray Generator and Development of Applied Technology

Diagnostics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Hiroaki Hasegawa ◽  
Masanori Sato

In regenerative medicine, evaluation of bone mineral density using a microfocus X-ray generator could eventually be used to determine the degree of bone tissue regeneration. To evaluate bone mineral density against regenerated bone material, two low-energy X-rays are necessary. Herein, the acquisition of quasi-monochromatic, dual-energy soft X-ray and the subsequent medical application were examined using the K-absorption edges of two types of metal filters (i.e., zirconium and tin) in a microfocus X-ray generator. Investigation of the optimal tube voltage and filter thickness to form a quasi-monochromatic energy spectrum with a single filter revealed that a filter thickness of 0.3 mm results in an optimal monochromatization state. When a dual filter was used, the required filter thickness was 0.3 mm for tin and 0.2 mm for zirconium at a tube voltage of 35 kV. For the medical application, we measured quasi-monochromatic, dual-energy X-rays to evaluate the measurement accuracy of bone mineral density. Using aluminum as a simulated bone sample, a relative error of ≤5% was consistent within the aluminum thickness range of 1–3 mm. These data suggest that a bone mineral density indicator of recycled bone material can be easily obtained with the quasi-monochromatic X-ray technique using a microfocus X-ray generator.

2002 ◽  
Vol 120 (1) ◽  
pp. 09-12 ◽  
Author(s):  
Lúcia Costa Paiva ◽  
Silvana Filardi ◽  
Aarão Mendes Pinto-Neto ◽  
Adil Samara ◽  
João Francisco Marques Neto

CONTEXT: Measurements of bone density taken by dual-energy x-ray absorptiometry are the most accurate procedure for the diagnosis of osteoporosis. This procedure has the disadvantage of measuring the density of all mineral components, including osteophytes, vascular and extra vertebral calcifications. These alterations can influence bone density results and densitometry interpretation. OBJECTIVE: To correlate radiography and densitometry findings from women with osteoporosis, analyzing the influence of degenerative processes and vertebral fractures on the evaluation of bone density. DESIGN: Retrospective study. SETTING: Osteoporosis outpatients' clinic at Hospital das Clínicas, Universidade Estadual de Campinas. PARTICIPANTS: Ninety-six postmenopausal women presenting osteoporosis diagnosed by bone density. MAIN MEASUREMENTS: Bone mineral density of the lumbar spine and femoral neck were measured by the technique of dual-energy x-ray absorptiometry, using a LUNAR-DPX densitometer. Fractures, osteophytes and aortic calcifications were evaluated by simple x-rays of the thoracic and lumbar spine. RESULTS: The x-rays confirmed vertebral fractures in 41.6%, osteophytes in 33.3% and calcifications of the aorta in 30.2%. The prevalence of fractures and aortic calcifications increased with age. The mean bone mineral density was 0.783g/cm² and the mean T-score was --3.47 DP. Neither fractures nor aortic calcifications had significant influence on bone mineral density (P = 0.36 and P = 0.09, respectively), despite the fractured vertebrae having greater bone mineral density (P < 0.02). Patients with lumbar spine osteophytes showed greater bone mineral density (P = 0.04). Osteophytosis was associated with lumbar spine bone mineral density after adjustment for fractures and aortic calcifications by multiple regression (P = 0.01). CONCLUSION: Osteophytes and lumbar spine fractures can overestimate bone density interpretation. The interpretation of densitometry results should be carried out together with the interpretation of a simple lumbar spine x-ray in elderly women.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 227.2-228
Author(s):  
D. Claire ◽  
M. Geoffroy ◽  
L. Kanagaratnam ◽  
C. Isabelle ◽  
A. Hittinger ◽  
...  

Background:Dual energy X-ray absoprtiometry is the reference method to mesure bone mineral density (1). Loss of bone mineral density is significant if it exceeds the least significant change. The threshold value used in general population is 0,03 g/cm2 (2). Patients with obesity are known for having a higher bone mineral density due to metabolism and physiopathology characteristics (3,4).Objectives:The aim of our study was to determine the least significant change in bone densitometry in patients with obesity.Methods:We conducted an interventionnal study in 120 patients with obesity who performed a bone densitometry. We measured twice the bone mineral density at the lumbar spine, the femoral neck and the total hip in the same time (5,6). We determined the least significant change in bone densitometry from each pair of measurements, using the Bland and Altman method. We also determined the least significant change in bone densitometry according to each stage of obesity.Results:The least significant change in bone densitometry in patients with obesity is 0,046g/cm2 at the lumbar spine, 0.069 g/cm2 at the femoral neck and 0.06 g/cm2 at the total hip.Conclusion:The least significant change in bone densitometry in patients with obesity is higher than in general population. These results may improve DXA interpretation in this specific population, and may personnalize their medical care.References:[1]Lees B, Stevenson JC. An evaluation of dual-energy X-ray absorptiometry and comparison with dual-photon absorptiometry. Osteoporos Int. mai 1992;2(3):146-52.[2]Briot K, Roux C, Thomas T, Blain H, Buchon D, Chapurlat R, et al. Actualisation 2018 des recommandations françaises du traitement de l’ostéoporose post-ménopausique. Rev Rhum. oct 2018;85(5):428-40.[3]Shapses SA, Pop LC, Wang Y. Obesity is a concern for bone health with aging. Nutr Res N Y N. mars 2017;39:1-13.[4]Savvidis C, Tournis S, Dede AD. Obesity and bone metabolism. Hormones. juin 2018;17(2):205-17.[5]Roux C, Garnero P, Thomas T, Sabatier J-P, Orcel P, Audran M, et al. Recommendations for monitoring antiresorptive therapies in postmenopausal osteoporosis. Jt Bone Spine Rev Rhum. janv 2005;72(1):26-31.[6]Ravaud P, Reny JL, Giraudeau B, Porcher R, Dougados M, Roux C. Individual smallest detectable difference in bone mineral density measurements. J Bone Miner Res. août 1999;14(8):1449-56.Disclosure of Interests:None declared.


1995 ◽  
Vol 4 (2) ◽  
pp. 141-148
Author(s):  
Ryuzou Takaya ◽  
Masakuni Tokuda ◽  
Tatsuya Oguni ◽  
Haruki Tanaka ◽  
Kazutaka Konishi ◽  
...  

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