Three-phase bone scintigraphy of hydroxyapatite ocular implants
Three-phase bone scintigraphy of hydroxyapatite ocular implants
复制标题
羟基磷灰石眼部植入物的三相骨闪烁扫描
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
U. Scholz
中科院分区：
文献类型：
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作者：
T. Leitha;A. Staudenherz;U. Scholz
羟基磷灰石眼植入物是通过水热化学交换反应从造礁珊瑚的外骨骼中提取的板层骨组织的复制品。它们附着在眼肌上，作为纤维血管向内生长的被动框架，可以钻孔来固定人工眼睛的可见部分，并允许眼球同步运动。在钻孔之前，纤维血管向内生长必须通过骨显像确认。本研究在12个月内监测了10例患者血管向种植体的生长情况，以建立临床可行的成像方案。在静脉注射600 MBq 99mtc - dpd后，通过动态和单光子发射断层扫描（SPET）目视和定量地监测示踪剂积累。植入物在动脉或血池期未见示踪剂积累。因此，动态闪烁成像可以从成像方案中省略。迟发性示踪剂积累不早于术后2个月，也不晚于术后6个月。平面显像不推荐使用，因为高分辨率SPET是将种植体与周围骨分离所必需的。我们得出的结论是，在注射示踪剂后3小时，不早于手术后3个月，成像可以局限于高分辨率的SPET。血管化羟基磷灰石眼窝植入物是一种重要的体内模型，可以独立于任何软组织和骨病研究寻骨剂的摄取动力学。我们的研究结果证明，在正常骨骼中，99mtc - dpd在羟基磷灰石晶体结构中的化学吸附是唯一定量相关的摄取机制。
Hydroxyapatite ocular implants are replicas of lamellar bone tissue derived from the exoskeleton of a reef-building coral by a hydrothermal chemical exchange reaction. Attached to the eye muscles, they act as a passive framework for fibrovascular ingrowth and can be drilled to hold the visible part of the artificial eye and allow synchronous eye movement. Fibrovascular ingrowth has to be confirmed by bone scintigraphy before the drilling procedure. This study monitored the vascular ingrowth into the implant in ten patients over 12 months to establish a clinically feasible imaging protocol. Tracer accumulation was monitored visually and quantitatively in dynamic and single-photon emission tomography (SPET) scans after the intravenous administration of 600 MBq of99mTc-DPD. The implants showed no tracer accumulation in the arterial or blood pool phase. Accordingly, dynamic scintigraphy can be omitted from the imaging protocol. Delayed tracer accumulation appeared no earlier than 2 and no later than 6 months after surgery. Planar scintigraphy is not recommended as high-resolution SPET is necessary to separate the implant from the surrounding bone. We conclude that imaging can be confined to high-resolution SPET 3 h after tracer injection, no earlier than 3 months after surgery. The vascularized hydroxyapatite orbital implant is an important in vivo model for bone-seeking agents to study their uptake kinetics independently of any soft tissue and bone disease. Our results provide evidence that in normal bones the chemical adsorption of99mTc-DPD into the crystalline structure of hydroxyapatite is the only quantitatively relevant uptake mechanism.