A NEW SET OF CALIBRATION STANDARDS FOR ESTIMATING THE FAT AND MINERAL-CONTENT OF VERTEBRAE VIA DUAL ENERGY QCT
A NEW SET OF CALIBRATION STANDARDS FOR ESTIMATING THE FAT AND MINERAL-CONTENT OF VERTEBRAE VIA DUAL ENERGY QCT
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DOI：
10.1016/0169-6009(91)90070-g
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发表时间：
1991-06-01
期刊：
影响因子：
--
通讯作者：
CHESNUT, CH
中科院分区：
文献类型：
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作者：
GOODSITT, MM;JOHNSON, RH;CHESNUT, CH
一套新的校准标准已被开发用于实施双能量（DE）定量CT技术，以估计椎骨的脂肪和骨含量。 QCT技术基于骨的三组分模型，并利用在其X射线衰减特性中模拟这些组分的校准材料。 我们选择模拟的三种成分是骨（矿物质加胶原蛋白），脂肪和无脂肪的红骨髓。 这一选择是基于我们希望采用的材料，这将有助于以后的实验验证的方法。 校准标准品和一组测试样品由组织模拟环氧树脂制成。 他们受雇于该技术的准确性（一致性）和精密度的研究，并在21名正常绝经后妇女的研究。 供试品的骨和脂肪含量估计值与生产商的质量标准一致，分别在13 mg/ml和7 vol%范围内。 两种量的长期重现性（变异系数）约为3%。 人类受试者的T12-L3椎骨的平均骨含量为262 +/-32 mg/ml（152 +/-18 mg/ml羟基磷灰石或矿物质钙），平均脂肪含量为63 +/-8%。 这些椎骨的常规单能（SE）QCT测量值比DE矿物质测量值低约23%，这与其他人通过化学分析确定的SEQID和灰分含量之间的差异一致。 DE脂肪含量的绝对值比文献中报告的值高约15%，这可能是由于红骨髓的假定组成存在错误。 骨和脂肪估计值的真实准确度将在计划的人体椎骨标本研究中确定。
A new set of calibration standards has been developed for implementing a dual-energy (DE) quantitative CT technique for estimating the fat and bone content of vertebrae. The QCT technique is based upon a three-component model of bone and utilizes calibration materials that mimic those components in their X-ray attenuation properties. The three components we chose to simulate are bone (mineral plus collagen), fat and a fat-free red marrow. This choice was predicated upon our desire to employ materials that would facilitate later experimental verification of the method. The calibration standards and a set of test samples were manufactured of tissue-simulating epoxy resins. They were employed in studies of the accuracy (consistency) and precision of the technique and in a study of 21 normal postmenopausal women. Estimates of the bone and fat content of the test samples were consistent with the manufacturer's specifications to within 13 mg/ml and 7 vol%, respectively. Long-term reproducibility (coefficient of variation) for both quantities was about 3%. The average bone content of the T12-L3 vertebrae of the human subjects was 262 +/- 32 mg/ml (152 +/- 18 mg/ml calcium hydroxyapatite or mineral) and the average fat content was 63 +/- 8%. Conventional single energy (SE) QCT measurements of these vertebrae were about 23% less than the DE mineral measurements, which is consistent with the differences between SEQCT and ash content that other have determined via chemical analysis. The DE fat content is, in absolute terms, about 15% greater than values reported in the literature and may be due to an error in the assumed composition of red marrow. The true accuracy of the bone and fat estimates is to be determined in a planned human vertebral specimen study.