Population-based geographic variations in dxa bone density in Europe: The evos study

The purpose of this study was to investigate variations in bone density between 16 European populations, 13 of which were participants in the European Vertebral Osteoporosis Study (EVOS). Men and women aged 50–80 years were recruited randomly from local population registers, stratified in 5-year age bands. The other three centres recruited similarly. Random samples of 20–100% of EVOS subjects were invited for dual-energy X-ray absorptiometry (DXA) densitometry of the lumbar spine and/or proximal femur using Hologic, Lunar or Norland pencil beam machines or, in one centre, a Sopha fan-beam machine. Cross-calibration of the different machines was undertaken using the European Spine Phantom prototype (ESPp). Highly significant differences in mean bone density were demonstrated between centres, giving rise to between-centre SDs in bone density that were about a quarter of a population SD. These differences persisted when centres using Hologic machines and centres using Lunar machines were considered separately. The centres were ranked differently according to whether male or female subjects were being considered and according to site of measurement (L2–4, femoral neck or femoral trochanter). As expected, bone mineral density (BMD) had a curvilinear relationship with age, and apparent rates of decrease slowed as age advanced past 50 years in both sexes. In the spine, not only did male BMD usually appear to increase with age, but there was a highly significant difference between centres in the age effect in both sexes, suggesting a variability in the impact of osteoarthritis between centres. Weight was consistently positively associated with BMD, but the effects of height and armspan were less consistent. Logarithmic transformation was needed to normalize the regressions of BMD on the independent variates, and after transformation, all sites except the femoral neck in females showed significant increases in SD with age. Interestingly, the effect of increasing weight was to decrease dispersion in proximal femur measurements in both sexes, further accentuating the tendency in women for low body mass index to be associated with osteoporosis as defined by densitometry. It is concluded that there are major differences between BMD values in European population samples which, with variations in anthro-pometric variables, have the potential to contribute substantially to variations in rates of osteoporotic fracture risk in Europe.     

乳腺癌的影像学

由于x线检查方法的进步,对乳房疾病患的诊断能力也在不断提高,有一些在临床上还不能肯定的病变,利用X线检查而得以确诊。因此,广泛应用x线检查对防癌普查发现早期病变以及鉴别肿瘤和非肿瘤病变、区别良性和恶性肿瘤上都具有重要意义。     

影像学在肿瘤诊治中的作用

医学影像学飞速发展,对临床医学的发展起到强大的推动作用。本文重点论述影像学在肿瘤诊治中的作用,及各种方法的优缺点。     

Value of a laser guidance system for CT interventions: a phantom study

The aim of this study was to check the handling and usefulness of a laser puncture system. The laser has tacking optics and is fastened to a sledge with angle graduation. The sledge runs on a bar fixed to the computerized tomograph (CT) parallel to the scan level. By means of a phantom, three experienced and seven inexperienced physicians made punctures with and without laser, using varying angles in single and double angulation. The distance from needle tip to target was measured. The handling of the puncture system proved to be problem-free. With both single and double angulation, the measurement differences with and without support were so small among experienced puncturers that there was no significant difference, with the exception of one double angulation (10 °/45 °). Among the beginners, there was a significant difference (P < 0.001, P < 0.05), with both single and double angulation. The accuracy of the beginners improved with use of the laser; experienced puncturers may profit from practice with small and hard-to-reach focuses. In terms of educational benefits, the laser guidance system offers great advantages and increased confidence for beginners. Received: 16 May 1997; Revision received: 16 March 1998; Accepted: 13 May 1998     

7.0 TMR关节软骨自旋锁定三维自旋-晶格弛豫时间成像与量化分析的实验研究

目的 建立MR关节软骨自旋锁定旋转坐标系中的自旋-晶格弛豫时间(T1ρ)三维成像技术和量化分析方法.方法 用7.0 T MR机和内径为6 cm的圆柱形鸟笼23Na-H射频线罔,采用自旋锁定自动补偿脉冲簇和三维自旋回波序列,自旋锁定时间(spin-locking time,TSL)分别为0、10、20、30、40和50 ms,自旋锁定频率带宽为440 Hz(自旋锁定磁场BsL),对6个不同浓度(1%～6%)琼脂糖凝胶体模和8个猪髌骨分别进行自旋锁定T1ρ成像扫描,建立自旋锁定T1ρ成像技术并评价其重复性.在Vnmr J图像终端上,利用自行编制的软件进行三维重组自旋锁定T1ρWI,并重构T1ρ弛豫时间图;采用人工标注的方法画感兴趣区,分别测定体模与髌骨软骨T1ρWI的信噪比(SNR)与T1ρ值.T1ρ值在各组间的对比,行单因素方差分析;软骨组织与琼脂糖体模SNR随时间对比关系的假设检验,行多因素方差分析.结果 关节软骨T1ρWI的SNR值、短自旋锁定时间采集图像的SNR值明显高于长自旋锁定时间采集的图像.在不同自旋锁定时间髌骨软骨T1ρWI,SNR值在48 4±8～95±8之间;不同自旋锁定时间,正常软骨SNR与1%琼脂糖体模的对比关系不同,当自旋锁定时间＜30 ms时,琼脂糖体模的图像SNR均低于正常软骨;＞30 ms时,正常软骨的图像SNR均低于1%的琼脂糖体模.随着琼脂糖浓度减少,不同自旋锁定时间采集的图像SNR值逐渐增加.各浓度琼脂糖凝胶体模T1ρ值测量的变异系数均小于10%,显示重复性好.髌骨关节软骨全层、表层、中间层、深层、钙化层T1ρ值测定结果分别为(68.9±6.3)、(80.7±12.8)、(65.7±7.0)、(82.4±7.7)、(69.7±6.4)ms(F=6.436,P＜0.05).T1ρ值在软骨表层和深层明显高于中间层、钙化层和软骨全层.结论 三维自旋锁定T1ρ成像技术是可行的、敏感的、特异的软骨分子成像技术,T1ρ弛豫时间图可量化测量关节软骨的分层状结构.     

自制AQA模体应用于射波刀质控的可行性分析

目的 探讨自制AQA模体应用于射波刀自动质量保证检测中的可行性。方法 在射波刀治疗计划系统中设计相同的自动质量保证检测治疗计划,分别在第四代（G4）射波刀和第五代（VSI）射波刀模式下使用自制AQA模体和AQA模体在相同条件下执行检测,各重复测量5次,分析比较2种模体检测结果的差异。结果 自制AQA模体与AQA模体在G4射波刀下自动质量保证检测总偏差结果分别为（0.28±0.12） mm和（0.28±0.15） mm,在VSI射波刀下检测结果分别为（0.46±0.19） mm和（0.50±0.07） mm,差异均无统计学意义（P> 0.05）;总偏差检测结果均小于1.0 mm,符合WS 667—2019 《机械臂放射治疗装置质量控制检测规范》。结论 自制AQA模体与AQA模体在自动质量保证检测中结果具有一致性,自制AQA模体可用于射波刀质量控制。     

小儿肠套叠复位术受照剂量的测量与分析

目的 调查分析X射线引导下空气灌肠整复术中患儿的受照剂量,为降低患儿辐射损伤风险提供依据。方法 收集接受空气灌肠整复术治疗的肠套叠患儿的资料;筛选、整理出3个不同年龄段的高、中、低组实验的条件,利用仿真人体模型模拟手术现场,借助热释光系统对患儿受照剂量进行测量。结果 肠套叠患儿在X射线引导下行空气灌肠整复治疗,成功率为88%（含再套叠者）、早期再套叠率为8%。该治疗中患儿有效剂量范围为0.57～12.33 mSv,吸收剂量较高的组织、器官多集中于胸部、腹部。结论 不同实验组患儿受照剂量差距较大,受照剂量不容小觑。建议操作者优选超声引导,若选择X射线引导,应尽量减少曝光时间,并为患儿规范佩戴防护用品,从而保障患儿健康。