Peller P J, Ho V B, Kransdorf M J
Department of Radiology, Walter Reed Army Medical Center, Washington, DC.
Radiographics. 1993 Jul;13(4):715-34. doi: 10.1148/radiographics.13.4.8356264.
Scintigraphy with technetium-99m methylene diphosphonate (MDP) delineates a wide spectrum of nonosseous disorders. Neoplastic, hormonal, inflammatory, ischemic, traumatic, excretory, and artifactual entities demonstrate abnormal soft-tissue uptake of Tc-99m MDP. Mechanisms leading to increased extraosseous Tc-99m MDP uptake include extracellular fluid expansion, enhanced regional vascularity and permeability, and elevated tissue calcium concentration. The composition of the calcium deposition and the presence of other metallic ions (eg, iron and magnesium) are important. Soft-tissue Tc-99m MDP uptake is seen in benign (tumoral calcinosis, myositis ossificans) and malignant (sarcomas, adenocarcinomas, metastases) neoplastic entities. Hormonal disturbances in calcium metabolism, especially in hyperparathyroidism, can lead to metastatic calcification, visualized with Tc-99m MDP scintigraphy. Tissue damage from inflammation, infection, or physical trauma results in localized hyperemia, edema, or calcium (and hemosiderin) deposition based on their pathophysiologic characteristics. Urinary tract obstruction, anomalies, or dysfunction are demonstrated by Tc-99m MDP imaging. Common artifacts are related to faulty radiopharmaceutical preparation, Tc-99m MDP administration, and imaging technique. Recognition of these modes of extraskeletal Tc-99m MDP uptake can enhance the diagnostic value of bone scintigraphy.
锝-99m亚甲基二膦酸盐（MDP）闪烁扫描可显示多种非骨疾病。肿瘤性、激素性、炎症性、缺血性、创伤性、排泄性及伪像性病变均表现为软组织对锝-99m MDP摄取异常。导致骨外锝-99m MDP摄取增加的机制包括细胞外液扩张、局部血管增多及通透性增强，以及组织钙浓度升高。钙沉积的成分及其他金属离子（如铁和镁）的存在很重要。软组织摄取锝-99m MDP可见于良性（肿瘤性钙化、骨化性肌炎）和恶性（肉瘤、腺癌、转移瘤）肿瘤性病变。钙代谢的激素紊乱，尤其是甲状旁腺功能亢进，可导致转移性钙化，锝-99m MDP闪烁扫描可显示。炎症、感染或物理创伤所致的组织损伤，根据其病理生理特征可导致局部充血、水肿或钙（及含铁血黄素）沉积。锝-99m MDP成像可显示尿路梗阻、畸形或功能障碍。常见伪像与放射性药物制备错误、锝-99m MDP给药及成像技术有关。认识这些骨外摄取锝-99m MDP的方式可提高骨闪烁扫描的诊断价值。
