Moser Lukas Jakob, Klambauer Konstantin, Diaz Machicado Maria Carolina, Frey Diana, Mergen Victor, Eberhard Matthias, Nowak Tristan, Schmidt Bernhard, Flohr Thomas, Distler Oliver, Alkadhi Hatem
From the Department of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland (L.J.M., K.M., V.M., M.E., T.F., H.A.); Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland (M.C.D.M., D.F., O.D.); Siemens Healthineers AG, Forchheim, Germany (T.N., B.S., T.F.); and Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands (T.F.).
Invest Radiol. 2025 Aug 1;60(8):535-542. doi: 10.1097/RLI.0000000000001159. Epub 2025 Feb 4.
The aim of this study was to determine in a prospective patient study the accuracy of areal bone mineral density (aBMD) measurements with spectral localizer radiographs obtained with a clinical photon-counting detector computed tomography (PCD-CT) scanner in comparison with dual-energy x-ray absorptiometry (DXA).
In this institutional review board-approved, prospective study, 41 patients (15 females, 26 males; mean age 61.3 years, age range 35-78 years) underwent PCD-CT of the abdomen with a spectral localizer radiograph (tube voltage 140 kVp, tube current 30 mA) and DXA within a median of 45 days. aBMD values were derived for lumbar vertebrae L1-L4 from both methods and were compared with linear regression, Pearson correlation, intraclass correlation coefficients (ICCs), and Bland-Altman plots. T-scores were calculated on a patient level and were compared between methods.
DXA and spectral localizer radiographs showed strong correlation in aBMD measurements ( R = 0.97, P < 0.001) and patient level T-scores ( R = 0.99, P < 0.001). There was a strong agreement between aBMD from both methods (ICC, 0.96; 95% CI, 0.94-0.97). Bland-Altman analysis revealed a very small mean difference in aBMD between methods (mean absolute error 0.019 g/cm 2 ) with narrow limits of agreement (-0.083 g/cm 2 to 0.121 g/cm 2 ). Similarly, there were small differences in regard to the T-score (mean absolute error 0.156) with narrow limits of agreement (-0.422 to 0.734) between methods. ICCs indicated an excellent agreement between T-scores from DXA and spectral localizer radiographs (ICC, 0.98; 95% confidence interval, 0.95-0.99).
Our prospective patient study indicates that spectral localizer radiographs obtained with a clinical PCD-CT system enable accurate quantification of the lumbar bone areal mineral density. This opens up the opportunity for opportunistic screening of osteoporosis in patients who undergo CT for other indications.
本研究的目的是在一项前瞻性患者研究中，确定使用临床光子计数探测器计算机断层扫描（PCD-CT）扫描仪获得的光谱定位X线片测量面积骨密度（aBMD）的准确性，并与双能X线吸收法（DXA）进行比较。
在这项经机构审查委员会批准的前瞻性研究中，41例患者（15名女性，26名男性；平均年龄61.3岁，年龄范围35-78岁）在中位时间45天内接受了腹部PCD-CT检查，并同时进行了光谱定位X线片（管电压140 kVp，管电流30 mA）和DXA检查。从两种方法中得出腰椎L1-L4的aBMD值，并通过线性回归、Pearson相关性、组内相关系数（ICC）和Bland-Altman图进行比较。在患者层面计算T值，并对两种方法进行比较。
DXA和光谱定位X线片在aBMD测量（R = 0.97，P < 0.001）和患者层面T值（R = 0.99，P < 0.001）方面显示出很强的相关性。两种方法的aBMD之间有很强的一致性（ICC，0.96；95%CI，0.94-0.97）。Bland-Altman分析显示两种方法之间aBMD的平均差异非常小（平均绝对误差0.019 g/cm²），一致性界限较窄（-0.083 g/cm²至0.121 g/cm²）。同样，在T值方面差异也很小（平均绝对误差0.156），两种方法之间的一致性界限较窄（-0.422至0.734）。ICC表明DXA和光谱定位X线片的T值之间有极好的一致性（ICC，0.98；95%置信区间，0.95-0.99）。
我们的前瞻性患者研究表明，使用临床PCD-CT系统获得的光谱定位X线片能够准确量化腰椎骨面积矿物质密度。这为因其他指征接受CT检查的患者进行骨质疏松症的机会性筛查提供了机会。
