In vivo skeletal imaging of 18F-fluoride with positron emission tomography reveals damage- and time-dependent responses to fatigue loading in the rat ulna.
In vivo skeletal imaging of 18F-fluoride with positron emission tomography reveals damage- and time-dependent responses to fatigue loading in the rat ulna.
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DOI：
10.1016/j.bone.2006.01.149
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发表时间：
2006-08
期刊：
影响因子：
4.1
通讯作者：
Matthew J. Silva;B. Uthgenannt;J. Rutlin;G. Wohl;Jason S. Lewis;M. Welch
中科院分区：
文献类型：
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作者：
Matthew J. Silva;B. Uthgenannt;J. Rutlin;G. Wohl;Jason S. Lewis;M. Welch
骨骼对破坏性疲劳载荷的反应尚不完全清楚。我们使用 18 F-氟化物PET来描述在体内疲劳引起的损伤水平不断增加之后骨骼反应的时间过程。 40只成年大鼠的右前肢在体内循环压缩至四级骨折下，疲劳位移：骨折位移的30%、45%、65%或85%。在第0天（4小时）、第2、4、7、9、11、18、24和30天给大鼠注射骨寻找放射性核素（18F-氟化物），并使用小型动物正电子发射断层扫描（PET）扫描仪进行成像。我们量化了右前肢（负载）和左前肢（对照）中央 50% 的氟化物吸收量。与对照组相比，所有位移组在第 0 天负载前肢的氟化物吸收量显着增加。标准化吸收（加载/对照）在加载后 4 至 9 天达到峰值水平。标准化吸收很大程度上取决于疲劳位移的水平。标准化摄取从 30% 位移水平逐渐增加到 45% 位移水平 (P < 0.001)，从 45% 位移水平逐渐增加到 65% 水平 (P < 0.001)，但在 65% 和 85% 之间没有差异 (P = 0.41)。在组织学上，我们观察到早在第 1 天就出现了快速的骨膜反应，血管供应增加，并且在第 3 天和第 7 天之间形成了丰富的编织骨。在遭受更多疲劳位移的骨骼中，骨膜和编织骨厚度更大。我们得出结论，单次疲劳负荷导致18 F-氟化物的吸收短暂增加，该吸收与初始损伤水平成比例，并且与负荷后第一周内血管分布增加和编织骨形成相关。
The skeletal response to damaging fatigue loading is not fully understood. We used18F-fluoride PET to describe the time course of the skeletal response following the creation of increasing levels of in vivo, fatigue-induced damage. The right forelimbs of 40 adult rats were loaded in vivo in cyclic compression to four levels of subfracture, fatigue displacement: 30, 45, 65, or 85% of fracture displacement. Rats were injected with a bone-seeking radionuclide (18F-fluoride) on days 0 (4 h), 2, 4, 7, 9, 11, 18, 24, and 30, and imaged using a small animal positron emission tomography (PET) scanner. We quantified fluoride uptake in the central 50% of the right (loaded) and left (control) forelimbs. There were significant increases in fluoride uptake in loaded forelimbs compared to control on day 0 for all displacement groups. Normalized uptake (loaded/control) reached peak levels 4 to 9 days after loading. Normalized uptake depended significantly on the level of fatigue displacement. Normalized uptake increased progressively from the 30 to the 45% displacement level (P < 0.001), and from the 45 to the 65% level (P < 0.001) but did not differ between 65 and 85% (P = 0.41). Histologically, we observed a rapid periosteal response with increased vascularity as early as day 1 and abundant woven bone formation between days 3 and 7. Periosteal and woven bone thicknesses were greater in bones subjected to more fatigue displacement. We conclude that a single bout of fatigue loading leads to a transient increase in the uptake of18F-fluoride, that the uptake is in proportion to the level of initial damage and is associated with increased vascularity and woven bone formation in the first week after loading.