Bone Density
Á¦¸ñ | QRM-EFP, European forearm phantom, QCT, DXA phantom |
QCT, DXA ¿¡¼ ¸ðµÎ »ç¿ëÇÒ ¼ö ÀÖ´Â Forearm PhantomÀÔ´Ï´Ù. ±æÀÌ°¡ ±ä ¸ðµ¨µµ ÀÖ½À´Ï´Ù. 5°¡Áö ¼½¼ÇÀ¸·Î ±¸¼ºµÇ¾î ÀÖÀ¸¸ç µÎ°³ÀÇ ÆȶÒÂÊ »ÀÀÇ ÇüÅÂó·³ ±¸¼ºµÇ¾î ½ÇÁ¦Ã³·³ Å×½ºÆ® ÇÒ ¼ö ÀÖ½À´Ï´Ù 5°¡Áö ¼½¼ÇÀ¸·Î ±¸¼ºµÈ °ñ¹Ðµµ ÆÒÅÒÀÔ´Ï´Ù. QRM-EFP, a phantom consisting of water- and bone-equivalent solid materials was devised to test peripheral bone densitometry systems. A prime design consideration of the forearm phantom was to use the same material as is used for the European Spine Phantom QRM-ESP-04 . This not only allows for the comparision of trabecular bone examinations at different locations and different machines, but also to compare axial with peripheral bone measurements. A circular cross section with a diameter of 60 mm was chosen, with the sides flattened by 10 mm to model the forearm. The inserts simulate trabecular bone and provide the basis for linearity checks of QCT systems. Density and thickness of the simulated compact bone is selected such that the phantom can be used to calibrate DXA and SPA machines as well. The phantom should allow one to test reproducibility and accuracy of machines, both in clinical installations and at manufacturers¡¯ sites. The following quantities can be determined: (i) bone area in cm2, (ii) thickness of cortical bone in mm, (iii) trabecular and cortical mineral density in g/cm3, (iv) bone mineral content (BMC) in g/cm, (v) bone mineral area density (BMD) in g/cm2. The three inserts of the phantom simulating large, medium and small bone have diameters of 28 mm, 21 mm and 14 mm, respectively. The calcium hydroxyapatite (HA) density of the simulated trabecular bone was selected according to the densities used in the European Spine Phantom QRM-ESP-04, namely 200, 100 and 50 mg HA/cm3. 1.2 mm was selected as the thickness of the cortical bone for section I + III and 0.6mm for section II. Its HA density was chosen as 800 mg HA/cm3. In addition to the three inserts a fourth insert was added to also enable valida-tions of SPA (single photon absorptiometry) systems. Quality control with CT guarantes a homogeneously distributed trabecular bone density with an average that deviates less than 1mg/cm3 from linearity. Specifications Base material: water-equivalent resin Phantom cross section: 60 mm x 40 mm Phantom length: 100 mm Phantom weight: 140 g Cortical bone: 800 mg HA/cm3 Trabecular bone: Section I: 200 mg HA/cm3 Section II: 100 mg HA/cm3 Section III: 50 mg HA/cm3 Section IV to VI: water-equivalent resin |
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