Erlichman M, Holohan T V
U.S. Department of Health and Human Services, Public Health Service, Agency for Health Care Policy and Research, Rockville, MD, USA.
Health Technol Assess (Rockv). 1996 Sep(9):i-vi, 1-31.
Bone mass loss and osteoporosis are associated with various conditions, such as asymptomatic primary hyperparathyroidism, and treatments, such as prolonged steroid therapy. Bone densitometry is used to measure bone mass density to determine the degree of osteoporosis and to estimate fracture risk. Bone densitometers measure the radiation absorption by the skeleton to determine bone mass of the peripheral, axial, and total skeleton. Common techniques include single-photon absorptiometry (SPA) of the forearm and heel, dual-photon (DPA) and dual-energy x-ray absorptiometry (DXA) of the spine and hip, quantitative computed tomography (QCT) of the spine or forearm, and radiographic absorptiometry (RA) of the hand. Part I of this report addresses important technical considerations of bone densitometers, including radiation dose, site selection, and accuracy and precision, as well as cost and charges. Part II evaluates the clinical utility of bone densitometry in the management of patients receiving prolonged steroid therapy. Steroids have broad effects on both immune and inflammatory processes and have been used to treat a wide variety of immunologically mediated diseases. Osteoporosis and vertebral compression fractures have been considered major complications of prolonged steroid therapy. Bone loss is also a direct result of many of the diseases treated with steroids. Issues addressed are the type and extent of bone loss associated with steroid therapy, risk for fracture, whether steroid dose reduction or alternative therapy is an option, and whether osteoporosis associated with prolonged steroid use can be prevented or treated. The other assessments in this series address the clinical utility of bone densitometry for patients with: asymptomatic primary hyperparathyroidism, end-stage renal disease, vertebral abnormalities, and estrogen-deficient women.
骨量丢失和骨质疏松与多种情况相关，如无症状原发性甲状旁腺功能亢进，以及与多种治疗手段相关，如长期使用类固醇疗法。骨密度测定用于测量骨密度，以确定骨质疏松的程度并评估骨折风险。骨密度仪通过测量骨骼对辐射的吸收来确定外周、轴向和全身骨骼的骨量。常用技术包括前臂和足跟的单光子吸收测定法（SPA）、脊柱和髋部的双光子吸收测定法（DPA）和双能X线吸收测定法（DXA）、脊柱或前臂的定量计算机断层扫描（QCT）以及手部的放射吸收测定法（RA）。本报告的第一部分阐述了骨密度仪的重要技术考量因素，包括辐射剂量、测量部位选择、准确性和精密度，以及成本和收费情况。第二部分评估了骨密度测定在接受长期类固醇治疗患者管理中的临床应用价值。类固醇对免疫和炎症过程均有广泛影响，已被用于治疗多种免疫介导性疾病。骨质疏松和椎体压缩性骨折一直被视为长期类固醇治疗的主要并发症。骨量丢失也是许多用类固醇治疗的疾病的直接后果。探讨的问题包括与类固醇治疗相关的骨量丢失类型和程度、骨折风险、是否可以选择降低类固醇剂量或采用替代疗法，以及与长期使用类固醇相关的骨质疏松是否可以预防或治疗。本系列中的其他评估涉及骨密度测定对以下患者的临床应用价值：无症状原发性甲状旁腺功能亢进患者、终末期肾病患者、椎体异常患者以及雌激素缺乏的女性。
