Jassel Inderbir S, Siddique Musib, Frost Michelle L, Moore Amelia E B, Puri Tanuj, Blake Glen M
School of Biomedical Engineering & Imaging Sciences, King's College London, St Thomas' Hospital, London, UK.
Osteoporosis Research Unit, King's College London, Guy's Hospital, London, UK.
Quant Imaging Med Surg. 2019 Feb;9(2):201-209. doi: 10.21037/qims.2019.01.01.
[F] sodium fluoride PET/CT provides quantitative measures of bone metabolic activity expressed by the parameters standardised uptake value (SUV) and bone plasma clearance ( ) that correlate with measurements of bone formation rate obtained by bone biopsy with double tetracycline labelling. Both SUV and relate to the tracer uptake in each millilitre of tissue. In general, the bone region of interest (ROI) includes both mineralised bone {generally with a high concentration of [F]NaF} and bone marrow (with a much lower concentration), suggesting that correcting SUV and for volumetric bone mineral density (vBMD) and measuring them with respect to the tracer uptake in each gram of bone mineral might improve the correlation with the findings of bone biopsy. As a first test of this hypothesis, we looked for positive correlations between SUV and values with CT and DXA bone mineral density (BMD) parameters measured in the same ROI.
A retrospective reanalysis was performed of 63 lumbar spine [F]NaF PET/CT scans acquired in four earlier studies. The quantitative PET parameters SUV and were measured in L1-L4 and Hounsfield units (HU) measured on the CT scans in the same ROI. Spine BMD data was also obtained from DXA scans in the form of areal BMD and used to derive the bone mineral apparent density (BMAD, an estimate of vBMD). Scatter plots were drawn of SUV and against HU, BMAD and areal BMD and the Spearman rank correlation coefficients derived for each plot.
All correlations were positive and statistically significant. Correlations were highest for HU (SUV: R =0.513, P<0.0001; : R =0.429, P=0.0005) and lowest for areal BMD (SUV: R =0.353, P=0.005; : R =0.274, P=0.03).
The results demonstrate significant positive correlations between SUV and and vBMD measurements in the form of HU from CT or BMAD and areal BMD from DXA. These findings justify further exploration of the relationship between SUV and [F]NaF PET/CT measurements and CT or DXA measurements of vBMD to examine whether normalization for bone density might improve their correlation with bone metabolic activity as measured by bone biopsy.
[F]氟化钠正电子发射断层显像/计算机断层扫描（PET/CT）可通过标准化摄取值（SUV）和骨血浆清除率（ ）参数对骨代谢活性进行定量测量，这些参数与通过双四环素标记骨活检获得的骨形成率测量值相关。SUV和 均与每毫升组织中的示踪剂摄取有关。一般来说，感兴趣的骨区域（ROI）包括矿化骨{通常[F]NaF浓度较高}和骨髓（浓度低得多），这表明校正SUV和 以反映体积骨密度（vBMD），并根据每克骨矿物质中的示踪剂摄取来测量它们，可能会改善与骨活检结果的相关性。作为对这一假设的首次检验，我们在同一ROI中寻找SUV和 值与CT和双能X线吸收法（DXA）骨密度（BMD）参数之间的正相关关系。
对四项早期研究中获取的63例腰椎[F]NaF PET/CT扫描进行回顾性重新分析。在L1-L4测量定量PET参数SUV和 ，并在同一ROI的CT扫描上测量亨氏单位（HU）。脊柱BMD数据也以面积BMD的形式从DXA扫描中获得，并用于推导骨矿物质表观密度（BMAD，vBMD的估计值）。绘制SUV和 相对于HU、BMAD和面积BMD的散点图，并为每个图得出斯皮尔曼等级相关系数。
所有相关性均为正且具有统计学意义。与HU的相关性最高（SUV：R =0.513，P<0.0001； ：R =0.429，P=0.0005），与面积BMD的相关性最低（SUV：R =0.353，P=0.005； ：R =0.274，P=0.03）。
结果表明，SUV和 与以CT的HU形式、DXA的BMAD和面积BMD形式的vBMD测量值之间存在显著正相关。这些发现证明有必要进一步探索SUV和 [F]NaF PET/CT测量值与CT或DXA的vBMD测量值之间的关系，以检验骨密度标准化是否可能改善它们与骨活检测量的骨代谢活性之间的相关性。
